US1497836A - Grinding compound - Google Patents

Description

Patented June 17, 1924.

human STATES PATENT ounce.

GEORGE W. BENEDICT, F

MINNEAPOLIS, MrnNEsorA, assrenon, BY mEsnE ASSIGN- MENTS, TO WOOD-IMIES MANUFACTURING COMPANY, Oi MINNEAPOLIS, MINNE- SOTA, A CORPORATION OF SOUTH DAKOTA.

GRINDING COMPOUND.

Ho Drawing.

To all whom it may concern:

Be it known that I, GEORGE W. BENEDICT, a citizen of the United States, resident of Minneapolis, in the county of Hennepin 6 and Stateof Minnesota, have invented certain new and useful Improvements in Grinding Compounds, of which the following is a specification.

This invention relates to improvements in W abrasiveor grinding compounds adapted to grind and finish the surface of metals. It is more particularly adapted for use in fitting, truing and removing the high spots from istons, cylinders, valves, valve seats and 0t or moving parts of engines and machinery.

Heretofore grinding compounds have consisted mainly of carborundum, emery, ground glass, and other abrasives of a relatively permanently abrasive nature. Such compounds 1y indefinite period and in using these compounds it is difficult, if not in the majority of cases impossible, to remove the compound after the proper grinding function is achieved; The carborundum', emery, ground lass or similar substance apparently works its way into the metal or about the part being treated and continues to grind after the proper fitting of the moving parts. Detrimental results obviously follow. Furthermore, as these substances are not thoroughly removed, they are apt to cause freezing of the working parts and scoring (as for exam le of engine cylinders), due to continue abrasive action and resultant friction. Likewise, the presence of such abrasive in a machine or engine is apt damage the parts between which there is movement. This novel compound is composed of an abrasive material which loses its 1 abrasive efi'ect and becomes smooth in a relatively short time during use on hard metals, such as cast-iron aluminum, lynite, magnolite, semi-steel, steel, and bronze. It is not intended for use on Babbitt metal. The selected abrasive materiak are sufiicientl hard and sharp to provide the desired grincl in so sir ed quantity of material may be em loyed to effect the correct grinding with t e asbecome smooth after a relativemixture to stand for action for a short period and the de- Application filed April 24,1922. Serial No. 556,330.

surance that the material will relatively rapidly become non-abrasive after its purpose has-been achieved. Thus, for example, in fitting and truing working parts of enines and machinery the above-mentioned igh spots may be removed and grinding action beyond the necessary point properly to fit the parts is prevented. Furthermore the novel compound is such that it may be rendered practically non-abrasive by use of lubricating oil.

The object therefore of this invention is to provide an improved grinding compound.

Other objects of the invention will more 7 fully appear from the following description and will be pointed out in the annexed claims. I

The principal ingredient of this novel grinding compound is the abrasive material and this material must have the attribute of relatively rapidly losing its abrasive property when used on hard surfaces. A

silica-like material 'presents the desired characteristics and the preferred silica-like ma- 1 terial is quartz. A uniform grade of quartz particularly adapted for the purposes of this compound may be obtained from the well-known quartz quarries in Indiana.

, The quartz is preferably employed in a finely divided state, being ground to pass a 140 mesh screen so that the piu-ticlesawill be fine, uniform and substantia y-free from foreign matter yet gritty and sharp.

A fluid is added to the ground quartz so that the mass is converted to a substantially viscous mass. The fluid employed is preferably one which exercises a cleansing efi'ect upon the surface being treated. The selected cleansing fluid must be substantially without lubricating qualities in order not to interfere with the abrasive function of the ground quartz. While a saponaceous liquid may be emplo ed for this purpose, it is preferable to use cleansing properties but little or no lubricatingqualities. It is to be noted that the best results are obtained by permitting the 36 to 48 hours and screening and stirring about once every 12 hours.

Preferably a body element or filler is em erosene or similar oils having ployed to overcome any tendency of the ground quartz and kerosene to form a coagulant mass. There are many organic substances suitable for this purpose such as wood powder, saw-dust, wool, peat, etc., in a finely divided state. However, it is found that ordinary egg-shells provide a ood filler to prevent coagulation. These s ells are crushed and so mixed with the quartz and kerosene. If used, the filler is added be.- fore the settin and stirring.

The proportions of the above-mentioned ingredients are such that the quartz predominates. Where ground quartz and kerosene are employed the preferred proportions are 150 pounds of quartz ground to 140 mesh to I 10 gallons of kerosene. If the filler be employed and egg-shells are the selected filler, then 30 pounds of egg-shells are used with the above-mentioned proportions of quartz and kerosene,

As above noted the com ound is preferably used in a substantially viscous form with the'egg-shells functioning to overcome any tendency ,to coagulation of the quartz and kerosene while the latter provides the desirable working consistency. and also provides the means for cleansing the surface being abraded by the compound. The eggshells also have a very slight abrading action in the nature of burnishing.

It has been found desirable to provide the compound with an odorous ingredient to predominate'over the smell of the kerosene. Therefore, an oil obtained'from green cedar leaves is used. This oil overcomes the smell of the kerosene and has little or no lubricat-.

ing qualities. However, it is to be understood. that other odorous substances may be employed in place of the odorant mentioned.-

When added to the compound prepared according to the above-mentioned proportions, about one-half pound' of this selected odorous oil is used.

In preparing the compound in the pre-- ferred proportions above specified, the filler, if used, is first mixed with the ground quartz, then such mixture is sifted into the kerosene, and the resultant semi-fluid mass is set, screened and stirred, as above-mentioned. If the odorous oilbe used, itisadded last.

In using the compound, it is'placed upon the surface to be ground and the compound is suitably pressed thereagainst, or the compound is placed between the co-operative surfaces to be treated and one of the bodies presenting such surfaces is moved while forcibly held against the other. The'particles of the abrasive ingredient of the compound being hard and sharp will quickly perform their abrading function and, from the nature of the preferred abrasive, will relatively rapidly lose their abrading property and will become substantially smooth and non-abrading and even if particles are process for fitting pistons to cylinders. The

present grinding compounds containing carborundum or emery are disadvantageous for this work due to the fact that particles of such hard abrasives are difiicult to remove completely from the cylinders and the abrading continues when the pistons and cylinders are put in use after the grinding is supposedly completed. In the present compounds, the particles of the abrasive material break or are crushed or ground by the abrading action into smaller hard sharp particles with new abrading points, edges or surfaces with the result thatthe abrading function continues relatively indefinitely.

.In the novel compound, the particles of the abrasive material do not break into smaller particles with renewed abrasive properties.

The size of the abrasive particles of this .novel compound will govern to a great extent the clearance thereby obtained in lap ping-in pistons. The 140 mesh compound is particularly adapted for lapping-in pistons for automobiles. Thus, such sized compound will give the 2-1000th clearance usual in this work. The compound is poured upon a piston in its cylinder and the piston is vertically reciprocated and turned-until the piston will drop under its own weight vertically through the cylinder while the compound is on the cooperative faces of the piston. The cutting life of each particle of this novel com ound is substantially definite. For example, 1f .the interior wall of a castiron cylinder be burnished by means of a sizing tool exerting a pressure upon the wall of 15 poundsper square inch, the particles of the compound above set forth will have a cutting life of 16 inches of travel upon the cast-iron walls. In other words the abrasive particles are worn smooth and their effective cutting function ceases. While several applications of this novel grinding compound are necessary in carrying out such lappingin process because the abrasive effect of each application relatively rapidly deteriorates, such disadvantages greatly overbalancedby the fact that even the dulled particles of the silica-like abrasive ingredient may be completely removed by the application of any of the common lubricating oils. The abrasive ingredient of this improved grinding compound eliminates the bad effect of the hard abrasives, such as carborundum, emery,

etc., working into the metal surface treated.

by the use of lubricating oil.

I claim as my invention:

1. A grinding compound composed of finely divided quartz, kerosene in proportion 'to form a substantially viscous mass,

and a filler proportionately added to prevent coagulation.

2. A grinding compound for metallic surfaces composed of finely divided quartz, a liquid having cleansing properties and substantially negligible lubricating properties, said liquid being proportionately added to roduce a substantially viscous mass, and a hller proportionately added to prevent ooagulation.

3. A grinding compound composed of ground quartz, kerosene, cedar oil and ground egg-shells in the proportions of pounds of quartz to 10 gallons of kerosene, pound of cedar oil and 5 pounds of eg shells.

In witness whereof, I have hereunto set my hand this 12th da of April, 1922. GEOR E W. BENEDICT.