JPS6215718B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the field of earthmoving tools, such as those used in rock and coal cutting machines or channel construction and road maintenance machines. For purposes of explanation, the invention will be described with respect to a road planer, a particular type of road construction and road maintenance equipment.

The tools to which this invention is most relevant consist of a base, a block (sometimes called a lug), and a bit in contact with the machining medium. The bits can be of any of several types known in the art.

A normal consequence of utilizing tools in abrasive machining media such as dirt is that the tools become worn and must therefore be replaced. The time during replacement is greater than when the bit is tipped with a hard wear resistant material such as tungsten carbide.

The tool is attached to a rotating rotor to drive the bit into the soil. Often the base and block are welded to the rotor and the bit is removably attached to the block. For normal operation, only the bit must be replaced. However, it has been observed that the blocks themselves are also subject to wear and even breakage. In this case, the entire machine is stopped, the old block is removed and
A welding machine must then be deployed to install the new block. Leaving such expensive machinery idle involves considerable expense.

Thus, for example, US Pat. No. 2,905,456;
It is desirable that the blocks also be interchangeable, as shown in Nos. 3,820,849 and 4,180,292.

This only partially solves the problem. i.e. buried railway tracks, manhole rings, expansion plates or deck plates on bridges, etc.
If an underground obstruction is encountered, an abnormally high cutting load will be applied to the bit and the base itself will be stripped from the rotor. If this happens, the machine must be taken out of service and the welder must be placed as before.

One way to improve this situation is to make the base and block heavy enough to withstand the cutting forces. This is shown for example in US Pat. No. 3,749,449. The result of this design is that the rotor is very heavy due to the increased base and block;
The force available for cutting action through the bit is somewhat reduced. Of course, such a design would also be expensive.

The present invention solves these problems of the prior art.

Thus, it is an object of the present invention to provide a base and block assembly that is both lightweight and durable.

Another object of the invention is to make the base and block assembly cost effective.

It is a further object of the invention to provide a base block assembly in which the blocks of the base block assembly are replaceable and yet are firmly held by the base during operation.

Yet another object of the invention is to provide a base, which protects the base of the block assembly from abnormally high cutting loads.

In accordance with the present invention, an assembly for use with an earthmoving bit is disclosed. A base and a block that engages within the base is provided. The block has a shank portion and a tool holder portion.
A tool holder portion extends from the first end of the shank portion and is adapted to receive an earthmoving bit. A mechanism is also provided for preferentially disabling the block when subjected to abnormally high cutting loads.

The base has a T-shaped recess formed by the intersection of a vertical slot and a horizontal slot. The block has a T-shaped portion extending from the second end of the shank portion. When fully engaged, the T-shaped portion slidably engages the T-shaped recess.

The deactivation mechanism is arranged on the shank part, preferably on the shank part between the tool holder part and the T-shaped part. Preferably, the deactivation mechanism also consists of a segment of the shank part whose cross-sectional area is reduced compared to the remainder of the shank part. Most preferably, the reduced cross-sectional area segment comprises a groove arranged along at least one circumferential surface of the shank portion.

The base also has a top portion consisting of two intersecting surfaces. Each top portion surface is inclined relative to the horizontal plane. The block also has a bottom portion consisting of two intersecting surfaces extending outwardly from the first end of the shank portion. Each bottom portion surface is inclined relative to the horizontal plane. When the block engages the base, the top surface of the base directly opposes the bottom surface of the block. Preferably, the angle that each of the top portion surfaces of the base makes with the horizontal plane and the angle that each of the bottom portion surfaces of the block makes with the horizontal plane is about 10 degrees.

More preferably, the horizontal slot and the top surface of the base diverge from each other towards the rear of the base.
The T-shaped portion and bottom portion surfaces of the block similarly diverge from each other towards the rear of the block. This divergence causes the base and block to wedge together as the block moves rearward within the base.

Also in accordance with the present invention, the base and block assembly preferably includes a mechanism for retaining the block in fixed engagement within the base. Preferably, this retention mechanism consists of a fastening means, a threaded recess formed in the rear of the shank portion, and a hole formed in the rear of the T-shaped recess. The holes and threaded recesses align when the block engages the base. The fastening means passes through the bore and engages the threaded recess.

In accordance with the present invention, a block for use with an earthmoving bit is disclosed. A tool holder portion is provided extending from the shank portion and a first end of the shank portion and adapted to receive an earthmoving bit. A mechanism is also provided for preferentially disabling the block when subjected to abnormally high cutting loads.

Preferably, the block also has a T-shaped portion extending from the second end of the shank portion.

Preferably, the deactivation mechanism is also arranged on the shank portion. More preferably, the deactivation mechanism is on the shank part between the tool holder part and the T-shaped part. The deactivation mechanism consists of a segment of the shank portion that has a reduced cross-sectional area than the remainder of the shank portion. Most preferably, the reduced cross-sectional area segment comprises a groove arranged along at least one circumferential surface of the shank portion.

The block also has a bottom portion consisting of two intersecting surfaces extending outwardly from the first end of the shank portion. Each bottom portion surface is inclined relative to the horizontal plane. Preferably, the angle that each bottom portion surface makes with the horizontal plane is about 10 degrees. Preferably, the T-shaped part and the bottom part surfaces diverge from each other towards the rear of the block.

In accordance with the present invention, a method of protecting the base of a block assembly when used with an earthmoving bit is also disclosed. The method consists of preferentially weakening and engaging the block with the base so that the block fails when subjected to abnormally high cutting loads. Preferably, the preferential weakening process step consists of reducing the cross-sectional area of a portion of the block. Most preferably, the process step of reducing the cross-sectional area comprises forming a groove along at least one circumferential surface of the block.

The nature of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

Referring to the drawings, FIG. 1 shows a base 2 and a block 4 as would normally be provided on a rotor 6. As shown in FIG.
As shown, the base is welded to the rotor as shown at 8.

2 and 3 show a block 4 with a base 2 and an earthmoving bit 10. The illustrated bit is a rotatable bit with its own keeper, but it could be any of several types known in the art. The cross section of the base in Figure 3 shows the engagement of the base, block and fastening means.

4-8, an assembly is disclosed for use with an earthmoving bit in accordance with the present invention. There is a base 2 and a block 4 that engages with the base. The block has a shank portion 12 and a tool holder portion 14 extending from a first end 16 of the shank and adapted to receive an earthmoving bit 10. A mechanism is also provided for preferentially disabling the block when subjected to abnormally high cutting loads.

The base has a vertical slot 20 and a horizontal slot 22
It has a T-shaped recess 18 formed by intersecting with. The block has a T-shaped portion 24 extending from a second end 26 of the shank portion. The T-shaped portion slidably engages the T-shaped recess.

Preferably, the deactivation mechanism is located on the shank portion 12. Further advantageously, the deactivation mechanism can also be arranged on the shank part between the tool holder part and the T-shaped part. The deactivation mechanism consists of a segment of the shank part whose cross section is reduced compared to the rest of the shank part. Most preferably, the reduced cross-sectional area segment comprises a groove 28 located along at least one circumferential surface of the shank portion.

To achieve the objectives of the invention it is necessary that the groups be arranged along at least one circumferential surface. However, it is also within the scope of the invention for the grooves to be arranged on two or three or all circumferential surfaces of the shank portion.

Similar designs, such as optional thinning of the shank cross-section, are also within the scope of this invention.

The base may also have a top portion consisting of two intersecting surfaces 30. Each top portion surface is inclined relative to the horizontal plane 32. The block also has a bottom portion consisting of two intersecting surfaces 34, the surfaces 34 extending outwardly from the first end 16 of the shank portion, each bottom portion being inclined with respect to a horizontal plane 36. When the block engages the base, the top surface 30 of the base directly opposes the bottom surface 34 of the block.

This is best seen in FIG. 2, where the top section surface is opposite the bottom section surface at 38. The purpose of slanting the bottom and top surfaces is to accommodate the lateral load of the earthmoving bit.

Preferably, the angle 40 that each of the top surfaces of the base makes with the horizontal plane and the angle 40 that the bottom surface of the block makes with the horizontal plane is about 10 degrees.

Preferably, the horizontal slot 22 and top surface 30 of the base diverge from each other toward the rear portion 42 of the base. T-shaped part 24 and bottom part surface 3 of the block
4 likewise diverge from each other towards the rear 44 of the block. This divergence causes a wedge engagement between the base and the block as the block moves rearward within the base.

Also in accordance with the invention, a mechanism is provided for holding the base and block in fixed engagement. It is desirable to maintain the base and block in fixed engagement to avoid unnecessary wear between the base and block.

Preferably, the retention mechanism includes a fastening means, a threaded recess 48 formed in the rear portion 44 of the shank portion, and a T.
It consists of a hole 50 formed in the rear part 42 of the shaped recess 18. Hole 50 and threaded recess 48 align when the block is engaged with the base. The fastening means engages the threaded recess through the hole.

The fastening means is a bolt 46 and a locking washer 47 as shown in FIG. However, similar fastening means such as bolts and springs are also within the scope of this invention.

In accordance with the present invention, a block 4 is disclosed for use with an earthmoving bit 10. A tool holder portion 14 is provided extending from the shank portion 12 and the first end 16 of the shank and adapted to receive the earthmoving bit 10. A mechanism is also provided for preferentially disabling the block when subjected to abnormally high cutting loads. The block also has a T-shaped portion 24 extending from the second end 26 of the shank portion.

Preferably, the deactivation mechanism is arranged on the shank part, more preferably the tool holder part and the T.
It is placed on the shank part between the shaped part. The deactivation mechanism consists of a segment of the shank part whose cross-sectional area is reduced compared to the remainder of the shank part. Most preferably, the reduced cross-sectional area segment comprises a groove 28 located along at least one circumferential surface of the shank portion.

Although grooves are specifically shown and described, any similar feature that reduces the cross-sectional area of the shank portion is also within the scope of the invention.

The block has a bottom portion consisting of two intersecting surfaces 34 extending outwardly from the first end 16 of the shank portion. Each bottom portion surface is inclined relative to the horizontal plane 36. The purpose of sloping the surface is to accommodate the lateral load of the earthwork bit. Preferably, the angle 40 that each bottom portion surface makes with the horizontal plane is about 10 degrees.

Preferably, the block also has a rear portion 4 of the block.
It has a T-shaped portion and a bottom portion surface 34 that diverge from each other towards 4.

In accordance with the present invention, a method of protecting the base of a base block assembly when used with an earthmoving bit is disclosed. This method consists of preferentially weakening the block and engaging it with the base so that the block fails when subjected to abnormally high cutting loads.

This method only renders the block inoperable or deformed to prevent further use when subjected to abnormally high cutting loads, thereby preventing the base from being stripped from the rotor. It is expected.

Preferably, the preferential weakening process step consists of reducing the cross-sectional area of a portion of said block. Most preferably, the process step of reducing the cross-sectional area comprises forming a groove 28 along at least one circumferential surface of the block. Although grooves are specifically illustrated and described as the most preferred method of preferential weakening, similar designs that reduce the cross-sectional area of the blocks are also considered to be within the scope of the present invention.

Many modifications may be made within the scope of the claims.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the base and block assembly on the rotor. FIG. 2 is a front view of the base and block assembly with the earthmoving bit.
FIG. 3 is a side view of the same. FIG. 4 is a side view of the block. FIG. 5 is a front view of the block.
FIG. 6 is a rear view of the block. FIG. 7 is a front view of the base. FIG. 8 is a side view of the base. 2...Base, 4...Block, 6...Rotor, 10
...Bit, 12...Shank part, 14...Tool holder part, 16...First end, 18...T-shaped recess, 20
...Vertical slot, 22...Horizontal slot, 24...T
Shaped portion, 26... Second end, 28... Groove, 30...
Top portion surface, 32...horizontal surface, 34...bottom portion surface,
36...Horizontal surface, 40...Corner, 42...Base rear, 4
4...Block rear part, 48...Threaded recess, 50...
Hole.

Claims (1)

What is claimed is: 1 a base, a block adapted to receive an earthmoving bit, the block having a shank portion and a tool holder portion engaging the base and extending from a first end of the shank portion; An assembly for use with an earthmoving bit comprising a mechanism for preferentially disabling said block when subjected to abnormally high cutting loads. 2 the base has a T-shaped recess formed by the intersection of a vertical slot and a horizontal slot, the block has a T-shaped portion extending from the second end of the shank portion, said T-shaped portion 2. An assembly according to claim 1, wherein the assembly is slidably engaged with the shaped recess. 3. The assembly of claim 2, wherein a deactivation mechanism is located on the shank portion between the tool holder portion and the T-shaped portion. 4. The assembly of claim 1, wherein a deactivation mechanism is located on the shank portion. 5. An assembly as claimed in claim 3 or 4, in which the deactivation mechanism comprises a segment of the shank part whose cross-sectional area is reduced relative to the remainder of the shank part. 6. The assembly of claim 5, wherein said reduced cross-sectional area segment comprises a groove disposed along at least one circumferential surface of said shank portion. 7. The base includes a top portion consisting of two intersecting surfaces, each of said top portion surfaces being inclined relative to a horizontal plane, and wherein the block extends outwardly from a first end of its shank portion. a bottom portion, each of said bottom portion surfaces being inclined with respect to a horizontal plane, and wherein when said block engages said base, said base portion surface directly opposes said block bottom portion surface. An assembly according to claim 3, wherein the assembly is adapted to: 8 The angles that each of the top surface of the base and each of the bottom surface of the block make with the horizontal plane are approximately
8. An assembly according to claim 7, wherein the angle is 10 degrees. 9 The horizontal slot and top surface of the base diverge from each other towards the rear of said base, and the T of the block
The shaped part and the bottom part surfaces likewise diverge from each other towards the rear of the block, such that when the block moves rearwardly within the base, the base and the block wedge into engagement due to the divergence. An assembly according to scope 7. 10. The assembly of claim 1 including a mechanism for holding the base and block in fixed engagement. 11 The holding mechanism includes a fastening means, a threaded recess formed at the rear of the shank portion, and the T
a hole formed in the rear of the shaped recess such that when the block is engaged with the base, the hole and the threaded recess are aligned and the fastening means passes through the hole and engages the threaded recess. Claim No. 10
Assembly as described in section. 12 a shank portion, and a tool holder portion extending from a first end of said shank portion and adapted to receive an earthmoving bit, and providing preferential failure of the block when subjected to abnormally high cutting loads; A block for use with an earthwork bit, consisting of a mechanism for 13. The block of claim 12 including a T-shaped portion extending from the second end of the shank portion. 14. The block of claim 13, wherein a deactivation mechanism is located on the shank portion between the tool holder portion and the T-shaped portion. 15. The block of claim 12, wherein a deactivation mechanism is located on the shank portion. 16. Claim 14 or Claim 1, wherein the malfunctioning mechanism comprises a segment of the shank part whose cross-sectional area is reduced compared to the remainder of the shank part.
Block described in item 5. 17. The block of claim 16, wherein said reduced cross-sectional area segment comprises a groove disposed along at least one circumferential surface of said shank portion. 18. Claim 14, further comprising a bottom portion consisting of two intersecting surfaces extending outwardly from the first end of the shank portion, each of the bottom portion surfaces being inclined relative to a horizontal plane. block. 19. The block of claim 18, wherein each of said bottom portion surfaces makes an angle of about 10 degrees with a horizontal plane. 20. The block of claim 18, wherein said T-shaped portion and bottom portion surfaces diverge from each other toward the rear of the block. 21. A method of protecting the base of a base-block assembly for use with earthmoving bits, the method comprising preferentially weakening said block so that said block fails when subjected to abnormally high cutting loads. and engaging the block with the base. 22. The method of claim 21, wherein the preferential weakening process step comprises reducing the cross-sectional area of a portion of the block. 23. The method of claim 22, wherein the step of reducing cross-sectional area comprises forming a groove along at least one peripheral surface of the block.