US1922917A - Grader blade - Google Patents

Description

z- 1933- c. A. RUSSELL ET AL 1,922,917

GRADER BLADE Filed Aug. 4, 1930 Char/es Russ e Car/'0 /7. Wa C) yyp gw Patented Aug. 15, 1933 UNlTED STATES 1,922,917 GRADER BLADE Charles A. Russell and Carroll M. Walker, Los

Angeles, Calif., assignors to Mills Alloys, Inc.,' Los Angeles, Calif., a Corporation of Delaware Application August 4, 1930. Serial No. 472,880

10 Claims.

This invention relates to a grader blade used on a motor or. tractor drawn grader for removing irregularities existing on the road or highway, and more particularly relates to a means for maintaining the surface of a road or highway at a uniformly smooth level.

Scraper blades have been quite generally used for levellinga road, but have not proven to be very efficient due to the lack of means which would cut and remove the knolls, mounds or ridges existing in the road beds. The conventional scraper blade merely rubbed over and removed the crowns or crests of these knolls and ridges, but invariably left the road surface in an uneven and bumpy condition. In order to make the surface substantially uniformly free from bumps or ridges, it was necessary to operate this blade over the roadmany times.

It is an'object of this invention to provide a means which will substantially and uniformly level the road surface in a single operation by the provision of means on the scraper blade which act on the irregularities existent on the road surface to cut and scrape in one operation.

It is a further object of this invention to provide a means which operates atmaximum efiicienc'y after the blade has been used. for a short interval. of time. 7 This is due to the formation of a plurality of small cutting surfaces of tungsten carbide or other hard :wear material, which are exposed when part ofthe bonding material has worn away due to friction.

It is a further object ofthis invention to provide a scraper blade having cutting elements which can be readily renewed as required.

It isa further object of this invention to provide a scraper blade which can be simply and inexpensively improvedto perform the function set out in the above objects.

Our invention possesses many other advantages, and has other objects which may be made more easily apparent from a consideration of one embodiment of our invention. For this purpose we have shown a form in the drawing accompanying and forming part of the present specification. We shall now proceed to describe this form in detail, which illustrates the general principles of our invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of our invention is best defined by the appended claims.

Referring to the drawing: 1

Figure 1 is a perspective view of a scraper blade embodying our invention; and

Fig. 2 is a sectional View substantially along the plane 2-2 of Fig. 1.

The scraper blade comprises a supporting structure 10 which may be curved, and to which is secured, at the lower portion thereof, a scraper blade 11. Any suitable fastening means may be employed, and as shown in the drawing, bolts-12 extend through openings in the scraper blade 11 and the supporting structure 10, and maintain them in the assembled position by means of nuts 13 screw threaded onto bolts 12. The head of each bolt 12 is maintained flush with the exposed face of the scraper blade 11 by countersinking the bore extending therethrough. The scraper blade has a, curvature corresponding to the curvature (if such curvature is used), ofthe supporting structure 10, and at the lower portion thereof a plurality of spaced teeth or cutting portions referred to as a whole as by 14 are secured in any. desirable manner, such as by welding or riveting. any desirable manner to the back portion of the supporting member 10 and in this manner provides a means for operatively supporting the scraper blade on a motor driven vehicle. The upper portion of the cradle 15 which is shown as curved as at 16, is adapted to coact with a corresponding curved part on the vehicle to operate the scraper at any desirable angle.

The cutting teeth 14 are formed by welding or mechanically fastening curved strips of iron or steel bosses or teeth 17 at spaced intervals on the lower portion of the scraper blade 11. In this manner a plurality of spaced projections or bosses are formed which act, when scraped over the road, to cut the knolls, mounds or ridges at or near the base portion thereof. The intervening exposed spaces 18 of the scraper blade 11 act toscrape or smooth over the surface of the road. As the spaces 18 are back of the operative faces of the teeth 14, the cutting action first takes place due to the projecting bosses, and this is followed by the consequent scraping action brought about by the spaced portions 18. Experimentation has shown that ribs or teeth, two inches in width and spaced two inches apart perform the best results, however, these dimensions are not to be construed as limiting, as it is within the purview of this invention to broadly cover spaced projecting portions on a cutting blade structure.

A yoke or cradle. 15 is secured in A mechanical mixture of tungsten carbide pariron or iron alloys on the tooth 17. This can be accomplished by means of an acetylene torch.

The action of the heat issuing from the acetylene torch tends to soften and melt the iron or iron alloy mixed with tungsten carbide particles 7 and also the surface of the projecting tooth 17 and thus provides a molten float or carrier which upon cooling retains the tungsten carbide particles on and embedded in the tooth. The iron, nickel or cobalt or alloys including iron, nickel or cobalt act as a binding and cushioning mate-- rial for the tungsten carbide particles. The tungsten carbide particles can vary in size between those that will pass through a 20 mesh screen and those that will stay on a 60 mesh screen.

The metal or alloy other than tungsten or carbon in the mechanical" mixture must not exceed 10% by weight. As the hardness of the bonding metal or alloy is considerably less than that of the tungsten carbide particles, their resistance to wear is materially less thanthat of the tungsten carbide particles. It is accordingly apparent that as the operation of the scraper blade continues, the action or friction of the road surface on the cutting tooth first tends to wear out the intervening or bonding layer of metal or alloy, and therefore exposes aface consisting of tungsten carbide particles- These particles present a multiplicity of wear resisting cutting edges which act to more thoroughly. out the uneven portions from the road surface. These minute cutting surfaces are continually maintained aslong as the tooth lasts, for they are always maintained in exposed position due to their great wear resisting characteristics. That is, the bonding material wears first and consequently maintains the exposed tungsten carbide particles. Should any one of these ribs .or-teeth becomebroken or fractured due to anyundue impact, each or all of. them may be'readily replaced. a

As a modification of the means disclosed for securing the tooth to the scraper blade 11, the

tungsten carbide particles may be first secured to the tooth 17 in a manner already described, and the tooth may then be secured to the scraper blade 11 by welding or by a suitable mechanical sten carbide of a size not smaller than those that will stay on a sixty mesh screen, nor larger than those that can pass through a twenty mesh screen.

4. In a scraper blade, means forlning a plurality of spaced projecting cutting portions, and a plurality of spaced scraping portions formed by said means, said means including particles of tungsten carbide.

5. In a scraper blade, means forming a plurality of spaced projecting cutting portions, and a plurality of spaced scraping portions formed by said means, said projecting portions alternating in the same horizontal plane with said scraping portions, with the operative faces of the latter behind the operative faces of the former.

6. Ina scraper blade, means forming a plurality of spaced projecting cutting portions, said cutting portions including particles of tungsten carbide, and a plurality of spaced scraping portions, the operative faces of which are behind the operative'faces of the cutting portions.

'7. In a scraper blade, a plurality of spaced scraping portions, and a plurality of spaced projecting cutting portions secured to the blade, said blade being characterized by a series of alternating cutting and scraping portions, the operative faces of the former being ahead of the operative faces of the latter, said cutting portions including particles of tungsten carbide.

8. In a scraper blade, means forming a plurality of spaced projecting cutting portions, said cutting portions including particles of tungsten carbide, and a plurality of spaced scraping portions, the operative faces of which are behind the operative faces of the cutting portions, said particles being of a size notsmaller than those that will stay on a sixty mesh screen, nor larger than those that can pass through a twenty mesh screen.

19. In a scraper blade, a plurality of spaced scraping portions, and'a plurality of spaced projecting cutting portions secured to the blade, said blade being. characterized by a series of alternating cutting and scraping portions, the operative faces of the former being ahead of the operative faces of the latter, theoperative faces.

of. thecutting portions being formed of particles of tungsten carbide including metals other than tungsten or carbon of an amount not exceeding 10% by weight. a 10. In. the combination set out inclaim 8 in which the tungsten. particles are of a size not smaller than those that will stay .on a sixty mesh screen, nor larger than those that can pass through a twenty mesh screen;

CHARLES A. RUSSELL.

CARROLL M. WALKER.

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