The Bridgeport evening farmer., 1916-04-13
GRINDING WHEEL ANUFACTURE IS
 LECTURE THEME
Foremen of Arms Company Enjoy InstrueffVe Illus
 trated Talk

Joyed, on Tuesday evening, at their regular semi meeting, an il- lustrated lecture by MT. Williams, sales manager of the Norton Grind- ing Wheel Co. of Worcester, Mass. MT williams chose as his subject tsGrinding Wheels the manufacture, use and care of same, and that his choice of subject was happy one was evidenced by the keen interest which was manifested by his listen
 He began by tracing the history of the abrasive wheel from it's ear Hest form, that ofs a. rough. hewn rock used by our serab civilized artl- sans to sharpen their hunting knives, up through from crude grinding stones used by our forefathers to the modern abrasive wheels with their numerous classif1cations and grades and shapes and uses. MT. Williams til 15 or IS years ago, grinding wheels had not progressed beyond the stage of a flat piece of sand. stone, pierced by a square hole somewhere near the center and hand chiseIed more or less round, mounted on two wooden horses. From then until about seven years ago, was said to be the period during which the mod ern abrasive wheel, with. all of its intricacies of manufacture was evolv- ed.
 A synopsis was then given Oft the methods used in tracing the abra- sive grains, which are the important part of grinding wheels, from the mine through electric furnaces and thence to the abrasive wheel man. 11facturer The material is obtained from the same mines as the a1umin- Irn wear manufacturers secure their materials. Because of the high grade of material necessary for I @S- ! produce is used. The lower grade. ore is used by the manufacturers of aluminium kitchen ware. The ma terial in this rough state is placed in wrought iron furnaces or kettles, mounted on a carbon plate. On the top of this carbon bed is placed a layer of charcoal. Then the, elec- trode is lowered into the furnace un- ! til it rests upon the charcoal In short while the charcoal burns out and the current jumps the gap thus formed. The material is then ShoV- eled in a rest to the proper tempera- ture, which is automatically control lied by means of grasshopper switch and allowed to remain for suitable length of time After cool f ing, the wrought iron jacket is lift l ed off and a hard glacious cylinder is ! found This is then broken up into i Jumps about the size of mans head i and passes along on a belt conveyor betMeeen sorters, who pick out those 4 luTnps which have some infused ma steriai in them. That material which l is found to be in the proper state, is | boxed up and shipped to the manu- facturer of abrasive wheels.
 When received, it is put through crushers which reduce the Jumps to 1 the minute particles which are used n the grinding whee1es. Material in it's granular stage is placed in large I hoppersl and fed down through tubes contxo1led at the nozzle by ordinary { molasses valves with automatic
 weighing attachments. A ga1vaniz- i ed iron ring is placed on a plaster ! paris plate and the eabrasive grains are distributed inside this ring,Which is roughly of the diameter and thick ness of the abrasive wheel wanted The mould is then filled with. the k binder and allowed to dry. After dry ] ing out sufficient to be worked on, it is shaved on the sides and face and then baked.
 MT. Williams spoke of the great < skill required in baking these wheels in the kilns, and the extraordinary care that was necessary. The kilnS used were equipped with every pos sibIe mechanical contrivance for reg 2 ulating the heat, but even then it was necessary to employ only the most
 skilled workmen to attend to this portion of the job. After being bak- ed, the wheels were sent to the tru- ing room, where they were trued and shaped according to the require where accurate dimensions were not so necessary, a, chilled iron cutter was used. For the finer grade wheels, and those of special shape, a dia- naord was necessary. On interesting fact in connection with the truing up of the abrasive wheels was that all of the dust was collected and used over again because of the value of the ma terial. The floor of the rooms where this process was carried on was swept up daily and the sweep1ngs saved
 After being brought to the proper shape and size, the wheels were test ed for hardness; the finer grade registering devices which register the amount of the penetration of a
 point, similar the screw driver
 point while for the rougher wheels a. similar point in. the hands of an expert workman was sufficiently fine for grading MT. Williams empha- sized the difficulty in grading the wheels to an exact standard, and stated that the classification now used
 was as finely drawn as was pracuca- bIe that is, that a. wheel could only be classed betweeen certain limits and not to a set constant. After being tested in this manner, the wheels were labeled and passed to another testing room where they are tested Tor Safe- tv The wheels were mounted on a frame and reyoIved at a surface speed of 9.Oa0efeet per minute All wheels
 over five. inches in diameter were tested in this way
 At the conclusion of the lecture MT. Williams was subjected to cross-fre questioning brought on by his own i invitation, and very ably gave satis- factory answers. The club was so pleased that they rendered Mir Will Hams a rising vote of thanks.
 Dr. EmmeTich,s Kit taE4 discoverer of liquid fire, ,fprmeFz GeFHane confidential . agent, serving a term in the Ohio State Penitentiary at Columbus, was grant ed permission by Warden Thomas to