US 1927818 A
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M. BRODERSEN 1,927,813
RIPPER TOOTH Filed Aug. 17, 1932 Inventor WWW ' A Homey J Patented Sept. 26, 1933 PATENT OFFICE RIPPER TOOTH Max M. Brodersen, Los Angeles, Calif assignor to Killefer Manufacturing Corporation, Ltd., Los Angeles, Calii'., a corporation of California Application August 17, 1932.
Serial No. 629,141
18 Claims. (01. 282-43) This invention relates to earth working tools and in particular to a digging tooth for use in earth, rock, and especially road working tools, so constructed as to produce such a tool as will 5 maintain its efllciency and working angles as the tooth wears away in use.
In one particular, it consists in the manner of distribution of extremely hard abrasive resistant material upon a certain cross section of tooth. The portion of the tooth which serves to penetrate the material initially is so, constructed as to retain a minimum area well supported in the direction of maximum stress. In addition, that portion of the tooth serving to displace and break up the material is likewise provided with the same type of abrasive resistant material, distributed in such a manner as to provide penetrating points along the cleavage planes which have been found to be most eflicient in breaking out such material with minimum power. Further, this abrasive resistant material is placed in such a manner that under normal use the wear of the tooth will take place in a way that will maintain these penetrating points in practically constant relation to each other and to the body portion of the tooth. In this manner an ideal cutting edge is maintained, and the lip angle, clearance, and back slope of the lip surface, likewise maintain their relations automatically as the tooth wears in service.
In road working tools in particular, such as for example: rippers, it is extremely important that these elements of the tooth remain at all times in correct relation to the material being worked. In such tools, efficiency is secured only by a correctly balanced relation between the direction of travel of the tooth, the working depth, the power applied, the resultant working forces on the tooth, and the manner in which the material being worked breaks out. Such a correct balance is secured only when the tooth angles are maintained in definite relation, as will be later described in the specification.
Broadly, the object of this invention is to produce a digging tooth of materials having different physical properties so distributed relative to the working angles and faces of the tooth and its normal position during use, as to maintain substantially the initial relation after long periods of use, and the consequent abrading away of the materials at the soil contact surfaces.
A further object of the invention is to produce a digging tooth wherein undesirable properties of one material are compensated by corresponding properties of the other, whereby the tooth as a whole will give unusually long and satisfactory service with maximum economy in the use of the materials of high cost.
Other objects will be apparent from the reading of the specification and the advantages pointed out therein.
While the drawing shows, and the specification describes, but one form of the invention, it is obvious that many changes may be made without departing from the broad invention as distinctly pointed out in the claims.
In the drawing:
Figure 1 is a side elevation of a tooth constructed in accordance with my inventions-partially in section;
Figure 2 is a top view thereof Figure 3 is a section taken on line 33 of Figure 1;
Figure 4 is a side elevation of the tool illustrated in working position in the soil and also showing the tool as it appears after a period of use.
Figure 5 is a fragmentary perspective view of the working end of the tooth;
Figure 6 illustrates the type of wear which takes place in the ordinary form of digger tooth;
Figure 7 shows the tooth of Figure 1 mounted oppositely on the shank from the mounting shown in Figure 4, such as may be used for more shallow ripping, scarifying and other uses where the lifting action is not predominant.
As illustrated, the tooth comprises a body 10, preferably of cast or forged steel, having a socketed upper end 11, for reception of the shank 12, and provided with lateral openings 13 for the reception of bolt heads 14, by which it is retained upon the shank 12. The shank 12 is attached to a wheeled carriage (not shown) by which it is supported. Opening 13a is provided for the escape of dirt from the socket. The working end 15 of the body is substantiallyof prismatic form with its section substantially triangular, but for purposes of support for the hard facing material, the edges 16 are somewhat flattened. In practice, the form is obtained from a basic circle inscribing the edges 16 and the top rib 17, between which flutes 16a are formed. The rib 17 serves to strengthen the tooth and to split up the material displaced, minimizing the tractive effort required to pull the tool. Smaller grooves 18 are also formed in the edges 16 for the reception of wear resistant material 19, such as tungsten carbide, other carbides of similar properties, or other hard compounds such as are known by the various trade names of Stellite, Stoodite, Hastellite.
These materials may be laid in the grooves in stick or granular form and appropriately bonded to the body material by welding, or may be embedded locally molten in the body material without the preforming oi the grooves. The grooves may be filled with such material in the form of welding or facing rods, or a bead of such material may be welded on the edge, all processes well known in the welding art.
As arranged for attachment to its shank 1,4,.
in one arrangement the triangular section of the body 15 is so oriented as to provide a bottom edge 20, and two side edges 21. The bottom edge 20, forms what may be called the hel" of the tooth. The working face, or lip surface, 22 is formed diagonally across the section extending from the bottom edge 20, rearwardlyupward, forming an acute angle designated as the flip angle" with the bottom edge. As supported in working position, the heel or bottom edge 20 will extend rearwardly upward at a small angle to the horizontal. The working face 22 extends rearwardly upward at a much greater angle with the horizontal with the bottom edge 20 intersecting the working face 22 at a point 23 in the position illustrated considerably in advance of the intersections 24 of the side edges 21 with the working face 22.
It will be seen that when such a tool is drawn along in the ground, the projecting point 23 will horizontally penetrate the soil breaking it upwardly toward the surface over the surface 22. The force of this, action will be exerted through the shank l4 and carriage of the tool to the drawbar in accordance with the proportioning and linkage of the connecting framework, location of the wheels, and the angle of the working face.
If the angle of the face is materially changed, the magnitude and direction of the balancing forces must likewise change, and either the tool will tend to dig deeper imposing a greater load on the wheels, or will tend to climb out, or to swing backward or forward changing the breaking out angle of the soil, and resulting in less eincient action than that for which the tool angle is initially set.
Figure 6 illustrates the manner in which an ordinary pointed tool will wear away. The original point 25 unsupported by harder materials extending along it even though it may be faced with such materials, Will break or wear away. This will leave such a point as 25a and often a heel or riding edge 26 sloped upwardly from the horizontal. Such a heel will produce a downward wedging component on the formation consuming excess tractive effort and imposing heavy pressure against the point increasing the wear thereon. a a
A tooth constructed in accordance with this invention is protected by the wear resistant materials against creating such a poor shape of digging tooth as just described. The wearing away of the softer material of which the body is formed will normally leave projecting points of the harder materials. These points will give the penetrating action required to crack the formation ahead. As the wear resistant material forms the outer edges of the tool, the tool will maintain its form and any tendency to wedge formation, either laterally or vertically is either completely resisted, or speedily corrected by the wearing away of the softer body material.
It will also be apparent that the wear resistant material extending parallel to the body surfaces extends into said forward face, and in which adsurface of the top rib 17 may also be protected with a bead of wear resistant material, but such has not been found tobe necessary inmost c'ases owing to the efficient maintenance of the lip surface, and, in fact, may actually be undesirable.
When used as in Figure 7, the heel 20 forms a leading cutting edge, serving to spread the material upwardly and outwardly, splitting the material, rather than lifting it bodily as is the case when the tool is used in the manner shown in: Figure 4. In the claims, the parts and relations of the tooth will be referred to as shown in position a for the purposes of definition and reference only, but it will be understood that the claims are to be considered as equally applicable to the parts when reversed in function and relation as. shown in Figure 7; and without limitation as to the position of use.
Having thus described one embodiment of my invention, I claim and desire to secure by Letters Patent:
l. A digger tooth including a body of substantially triangular section and prismatic form, the lateral edges thereof containing material having greater resistance to abrasion than the material of said body.
2. A digger tooth including a body having an earth lifting face, said body extending rearwardly therefrom and having a relatively narrow bottom edge, said bottom edge containing material having a greater wear resistance than the terial of said body.
3. A digger tooth including a body adapted for no horizontal travel within the earth having an upwardly and rearwardly directed forward face, said body extending upwardly and rearwardly at a lesser angle to the horizontal therefrom, and having relatively narrow side edges containing material having a greater wear resistance than the material of said body.
4. A digger tooth including a body adapted for horizontal travel within the earth having an upward andrearwardly directed forward face, the, rearwardly extending faces of said body carrying material having a greater resistance to wear than the material of said body.
5. A digger tooth as described in claim 4 in which the material of greater wear resistance extends into said forward face, thereby forming working portions of said face of said material.
6. A digger tooth as described in claim 4 in which the material of greater wear resistance which said body is provided with relatively narrow side edges containing material also having a greater wear resistance than the material of said 8. A digger tooth including a body having an earth lifting face, said body extending rearwardly therefrom and having a relatively narrow bottom edge, said bottom edge containing material having a greater wear resistance than the material of said body, said wear resistant material extending into said forward face thereby forming a narrow wear resistant leading point on said face.
9. A tooth as described in claim 3 in which said wear resistant material extends into said forward face thereby forming narrow wear resisting points at the sides of said face.
10. A digger point as described in claim 8 in which said body includes relatively narrow side edges also containing material of greater wear resistance than that of said body.
11. A digger tooth including a body having an earth lifting face, said body extending rearwardly therefrom and having relatively narrow bottom and side edges, said edges containing material 1 ant points are of material less wear resistant than that of said edges, whereby in use the material will partially wear away from around said points leaving projecting points of wear resistant material projecting from said face at the sides and bottom thereof. I
13. A tooth as described in claim 3 in which the wear resistant material extends into said forward face, and in' which the adjacent portions of said face are less wear resistant than said material,
whereby side portions of said face will present projecting points of wear resistant material as the tooth wears in service.
14. A digger tooth as described in claim 1 and including a rib extending along the upper face of body bonded thereto, .said beads being arranged to form the edges of a triangular prismof body material, and adapted for presentation to the formation angularly endwise.
16. A digger tooth including a body of substantially triangular section and prismatic formation, beads of material having a resistance to wear greater than that of the material of' said body extending along the edges thereof, the edges of said body being flattened and the wear resistant material embedded therein, the side faces of said body being provided with longitudinal flutes, and a longitudinal rib extending along the top face of said body,,and adapted for spreading the formation being worked in a lateral direction.
MAX M. BRODERSEN.