« НазадПродовжити »
is used. There will be a separate card for each kind and size of stock. All stock will be classified and proper guide cards will readily show the location of each class of stock cards. These classes will be sub-divided when necessary, the class guide cards and the sub-class guide cards being of different colors. These sub-classes may be advantageously again divided in some instances. For instance: Class, cap screws; sub-classes, round and hexagonal heads; in each of these sub-classes, soft and case-hardened. Nut blanks, square and hexagonal. Sheet steel, machine steel, spring steel, and tool steel. Sheet brass, hard and soft, etc.
When stock is received it will be entered on the proper card, giving the date of its receipt. As quantities are issued the date and amount is entered at each issue, the total carried out on the horizontal line, and at any time added vertically and subtracted from the total amount received will show the balance on hand. When this card is filled up the amount on hand is ascertained and carried on to another card against the word “forward,” and future operations entered as before.
Fig. 200. Requisition for Consumable Supplies, size,
54 x 8} in. Color, Manila. In order to prevent an unnecessary amount of any one stock, or of allowing the amount to get below a safe minimum, the stock keeper will watch the condition of his stock, note the amount issued within a certain time, and soon be able to fix maximum and minimum limits, within which the stock of each particular article is to be kept. These amounts he will enter on the upper right-hand corner of the
proper card. Should his first estimate in this respect not prove correct he may change it on subsequent cards.
By careful attention to this point he may save much unnecessary outlay for stock kept on the shelves, and should any changes occur he will have less old stock to work off. Once every three months the stock on hand may be inventoried as a check on the card account. If found substantially correct these periods may be lengthened to six months.
All consumable supplies issued will be upon requisitions of the form shown in Fig. 200. These will always be signed by a foreman, or other authority. One part of this blank will be retained by the stock keeper, and the other part, with the costs entered upon it, returned with the supplies.
Still another division of the store or stock room may be a storeroom for small finished parts purchased from outside manufacturers. The general system of receiving them and accounting to the purchasing clerk, caring for them and issuing them upon proper requisitions, is the same as in accounting for stock and supplies.
PATTERN SHOP SYSTEM
A field for a good system of management. The poorly created shop. Its proper location
and importance. Organizing the working force. Various kinds of labor necessary. Classifying the work. Qualifications of a skilled pattern maker. Selection of pattern lumber. A lumber drying room. Storing pattern lumber. The kind of lumber for patterns. How the lumber should be cut from the log. Economical use of pattern lumber. Caring for short lengths of pattern lumber. Working up scraps. Discrimination in the use of lumber. Fillets and dowels. System of marking and testing patterns. Making pattern letters and figures. The proper style of letter. Applying them to the pattern. Case for storing pattern letters. Care of wood fillets. The pattern maker's cabinet. Keeping wire nails, screws, etc. A color system for varnishing patterns. The pattern loft. Handling patterns. Overhead trolley tracks and trolley hoists. System of storing patterns. Pattern records. Card system for recording, issuing, and recovering patterns. Handling the card system. Time and cost keeping. Material and cost card. A complete system. Methodical and orderly management. Individual duties and responsibilities. The ideal pattern shop.
THERE is no department connected with the modern machine shop in which a good system of management, administered by a careful, methodical man, in a quiet and orderly manner, will be of more benefit to the establishment in general than the pattern shop. It is too often the case that this department is looked upon as being non-productive; a source of continual expense; not producing anything which may be sold at a profit; and consequently should be managed as cheaply as possible.
Therefore we see the pattern work done in a part of the shop not at all fitted for such work, possibly in one end of a machine room and subject to the iron dust and dirt which is not shut out by even a board partition, and sometimes by one only half the height of the room. We find it poorly equipped with inadequate and often obsolete machinery, supplied with poor lumber, and lacking many of the essentials for producing good work. Often men are employed because of the low wages they are willing to work for, rather than those of the requisite ability in their chosen trade.
There is always a vast difference between cheapness and economy, as the terms are generally understood, and these false ideas of economy generally result in the expenditure of more money finally than if such short-sighted
ideas gave way to the policy of seeking for the best, being willing to pay for it, and then expecting high efficiency of employees and the production of good work that would stand the test of hard usage, rather than that which must be frequently repaired and strengthened in order to keep it in use.
While these facts should be strenuously adhered to as to the regular work of the pattern shop intended for permanent use, we should not lose sight of the occasional jobs of pattern work intended for only a few castings, and therefore should be made with this end in view, and often at one half the expense of a thoroughly made, permanent pattern.
That there has been a good deal of improvement along these lines within the last few years is undoubtedly true, yet the fact remains that there is still in many shops room for more changes for the better, both in matters of economy of expense and a higher standard of workmanship.
The following plans and systems of handling the work are the result of practical experience as well as years of observation of this and kindred work, and it is hoped that they may offer practical suggestions to men having the responsibilities of administering the affairs of such a department.
In arranging the working force of the pattern shop a definite plan should be followed. This plan will depend to a great extent upon the kind of work that is to be done. That is, whether it is to be for large, medium, or small pattern, or perhaps a portion of each. Also, whether it is to be a good deal of new work, or a large proportion of the work is in altering patterns, or changing standard parts of them. In any event the one essential point to be considered is, to employ skilled or high priced pattern makers only on such work as need such ability, while all work that can be done by apprentices, or less skilled men, shall be done by them. For this as well as other evident reasons, getting out dimension lumber, making core prints, bosses, varnishing and marking patterns, and similar work, may be done by men at from half to two thirds of the pay that the skilled pattern maker receives. Therefore such machines as the planer, jointer, circular saws, etc., may be handled by the men who may be classed as “mill men,” who, while they are not conversant with pattern making as a trade, can get out such dimension lumber as the pattern makers require in less time and at much less cost.
The same will be the case with the man running the band saw in getting out segment work and then laying it up. Being employed on this class of work continually, he can not only do just as good work, but sometimes better, than a man who only does it occasionally, and of course do more of it and do it more economically. Putting in fillets, puttying, plugging screw-head holes, varnishing and rubbing down patterns, etc., is the work of an apprentice and not that of a skilled workman.
To obtain the most efficient and economical results from this department,
assuming that the work will be in the usual proportion of new work, alterations, repairs, etc., its force and the duties of the men should be classified somewhat as follows: A force of fourteen employees would consist of say one foreman, six skilled pattern makers, one lathe man, one planer man, one circular saw man, one band saw and segment man, one finisher and varnisher, one man for keeping pattern records, lettering patterns, etc., and one laborer.
For a force of ten employees there should be one foreman, four skilled pattern makers, one lathe man, one band saw and segment man, one man for keeping pattern records, finishing, varnishing, and lettering patterns, etc., and one laborer.
For a force of seven men there would be one foreman, three skilled pattern makers, one lathe, band saw, and segment man, one planer, jointer, and circular saw man, and one man for keeping pattern records, finishing, varnishing, and lettering patterns, etc. A laborer must be called from the yard or some part of the shop when wanted.
By finishing a pattern is meant putting in fillets, plugging screw-head holes, puttying, etc. In a force of ten men the lathe man will do whatever other work the foreman desires when he is not engaged on his special work. The man who keeps the pattern records looks after the issuing of patterns to the foundry and the storing of them when they are returned. An apprentice should be able to put in fillets, putty, varnish, rub down, etc., and where there are only a few men the foreman will keep the pattern records.
It should be understood that when we speak of a skilled pattern maker we mean one who thoroughly understands his business, and this is a matter not always properly understood by men who have not had practical shop experience in this particular line.
He must be able to read drawings quickly and thoroughly. He must have a good practical knowledge of molding from the patterns in the foundry, including those to be cast in “green sand,” dry sand, and prepared loam; of those molded from patterns, and those “swept up” by sweeps or “strickles,” and of the behavior of the various metals in casting, particularly of the different qualities of cast iron, of their liability to distortion, and the varying degrees of shrinkage.
He must have a practical idea of the effect of distortion of castings from patterns of different forms and proportions of solid and cored work.
He should know the correct amount of stock to allow for machining a casting when this is not specified on the drawings, and many other things besides the mere mechanical work of building up the pattern. In this part of the work he must know about the behavior of lumber when made into a pattern; how to so build up his pattern as to secure the greatest rigidity; to so dispose of the pieces of wood composing the pattern that its contraction and