No matches found 三星彩票计划

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    Software name: appdown
    Software type: Microsoft Framwork

    size: 812MB

    Lanuage:Englist

    Software instructions



      Judged upon theoretical grounds, and leaving out the mechanical conditions of operation, it would at once be conceded that a proper plan would be to move the lightest body; that is, if the tools and their attachments were heavier than the material to be acted upon, then the material should be moved for the cutting action, and vice versa. But in practice there are other conditions to be considered more important than a question of the relative weight of reciprocating parts; and it must be remembered that in solving any problem pertaining to machine action, the conditions of operation are to be considered first and have precedence over problems of strain, arrangement, or even the general principles of construction; that is, the conditions of operating must form a base from which proportions, arrangements, and so on, must be deduced. A standard planing machine, such as is employed for most kinds of work, is arranged with a running platen or carriage upon which the material is fastened and traversed beneath the cutting tools. [130] The uniformity of arrangement and design in machines of this kind in all countries wherever they are made, must lead to the conclusion that there are substantial reasons for employing running platens instead of giving a cutting movement to the tools.

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      In one of the inmost circles, a sacred elephant had gone must, breaking his ropes, and confined now by only one leg. The chains fastened round his feet as soon as he showed the first symptoms of madness were lying broken in heaps on the ground. The brute had demolished the walls of his stable and then two sheds that happened to be in his way; now he was stamping a dance, every muscle in incessant motion, half swallowing his trunk, flinging straw in every direction, and finally heaping it on his head. A mob of people stood gazing from a distance, laughing at his heavy, clumsy movements; at the least step forward they[Pg 113] huddled back to fly, extending the circle, but still staring at the patient. In an adjoining stable were two more elephants very well cared for, the V neatly painted in red and white on their trunks, quietly eating and turning round only at the bidding of the driver; but one of them shed tears.In view of these propositions, I need hardly say to what object machine improvements should be directed, nor which of the considerations named are most affected by a combination of machine functions; the fact is, that if estimates could be prepared, showing the actual effect of machine combinations, it would astonish [70] those who have not investigated the matter, and in many cases show a loss of the whole cost of such machines each year. The effect of combination machines is, however, by no means uniform; the remarks made apply to standard machines employed in the regular work of an engineering or other establishment. In exceptional cases it may be expedient to use combined machines. In the tool-room of machine-shops, for instance, where one man can usually perform the main part of the work, and where there is but little space for machines, the conditions are especially favourable to combination machines, such as may be used in milling, turning, drilling, and so on; but wherever there is a necessity or an opportunity to carry on two or more of these operations at the same time, the cost of separate machines is but a small consideration when compared with the saving of labour that may be effected by independent tools to perform each operation. The tendency of manufacturing processes of every kind, at this time, is to a division of labour, and to a separation of each operation into as many branches as possible, so that study spent in "segregating" instead of "aggregating" machine functions is most likely to produce profitable results.


      for dinner, both of which he appeared to appreciate. I was awfully

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