Holder Assembly

Abstract

In one aspect of the invention, a holder assembly comprises a connection block having a block bore extending from a first opening proximate a first end of the assembly to a second opening proximate a second end of the assembly. The block is adapted for connection to a driving mechanism. An extension element is disposed in the block bore and protrudes from the first opening of the block bore. The extension element comprises a central extension bore having a longitudinal length. An attachment mechanism is disposed within the central extension bore of the extension element and is disposed proximate the second end of the assembly.

Description

BACKGROUND OF THE INVENTION

Many industries including the asphalt, mining, construction, drilling, and excavation industries, utilize a plurality of picks incorporated into drums. In asphalt milling, a drum supporting an array of picks may rotate such that the picks engage a paved surface causing it to break up. Examples of degradation assemblies from the prior art are disclosed in U.S. Pat. No. 6,824,225 to Stiffler, US Pub. No. 20050173966 to Mouthaan, U.S. Pat. No. 6,692,083 to Latham, U.S. Pat. No. 6,786,557 to Montgomery, Jr., U.S. Pat. No. 3,830,321 to McKenry et al., US. Pub. No. 20030230926, U.S. Pat. No. 4,932,723 to Mills, US Pub. No. 20020175555 to Merceir, U.S. Pat. No. 6,854,810 to Montgomery, Jr., U.S. Pat. No. 6,851,758 to Beach, which are all herein incorporated by reference for all they contain.

The picks typically have a tungsten carbide tip. Efforts have been made to extend the life of these picks. Examples of such efforts are disclosed in U.S. Pat. No. 4,944,559 to Sionnet et al., U.S. Pat. No. 5,837,071 to Andersson et al., U.S. Pat. No. 5,417,475 to Graham et al., U.S. Pat. No. 6,051,079 to Andersson et al., and U.S. Pat. No. 4,725,098 to Beach, U.S. Pat. No. 6,733,087 to Hall et al., U.S. Pat. No. 4,923,511 to Krizan et al., U.S. Pat. No. 5,174,374 to Hailey, and U.S. Pat. No. 6,868,848 to Boland et al., all of which are herein incorporated by reference for all that they disclose.

U.S. Pat. No. 6,371,567 to Sollami, U.S. Pat. No. 6,357,832 to Sollami, and U.S. Pat. No. 5,992,405 to Sollami, each of which is hereby incorporated by reference for all that it contains, disclose methods of mounting cutting tools and securing cutting tools to the mounts

BRIEF SUMMARY OF THE INVENTION

In one aspect of the invention, a holder assembly comprises a connection block having a block bore extending from a first opening proximate a first end of the assembly to a second opening proximate a second end of the assembly. The block is adapted for connection to a driving mechanism. The driving mechanism may be a milling drum connected to the underside of a pavement milling machine or part of a milling machine. An extension element is disposed in the block bore and protrudes from the first opening of the block bore. The extension element comprises a central extension bore having a longitudinal length. An attachment mechanism is disposed within the central extension bore of the extension element and is disposed proximate the second end of the assembly.

The attachment mechanism may attach to the extension element within the block bore. The block and the extension element may be attached to one another via the attachment mechanism. In some embodiments the attachment mechanism may radially expand at least a portion of the extension element outward to engage an inner surface of the block bore. In such embodiments the attachment mechanism may comprise a wedge. The attachment mechanism may be inserted into the central extension bore of the extension element through the second opening of the block bore. The attachment mechanism may be adapted to interlock with the extension element. An external surface of the attachment mechanism may comprise ridges.

A longitudinal length of the central extension bore may be at least as long as a longitudinal length of the block bore. An internal surface of the block bore may comprise outwardly tapered surfaces. The central extension bore of the extension element may comprise an opening proximate the second end of the assembly. The extension element may comprise a plurality of coaxial central extension bores. One of the central extension bores may comprise an opening proximate the first end of the assembly and another central extension bore may comprise an opening proximate the second end of the assembly. In such embodiments a lubricant reservoir and a pick shank may each be disposed in the primary central extension bore.

The extension element may comprise slits proximate the second end of the assembly. A split ring may be disposed intermediate the inner surface of the central extension bore and an external surface of the extension element proximate the second end of the assembly. In some embodiments an external surface of the attachment mechanism may comprise a first set of threads that corresponds to a second set of threads disposed on an inner surface of the central extension bore. The attachment mechanism may protrude from the second opening of the block bore. The attachment mechanism may comprise an external end that protrudes out of the second opening of the block bore and contacts a surface of the block proximate the second end of the assembly. A pick shank may be disposed within the central extension bore and the pick shank may be connected to a wear-resistant impact tip.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional diagram of an embodiment of a pavement milling machine.

FIG. 2 is a cross-sectional diagram of an embodiment of a holder assembly.

FIG. 3 is a perspective diagram of an embodiment an attachment mechanism.

FIG. 4 is a perspective diagram of an embodiment of an extension element.

FIG. 5 is a cross-sectional diagram of an embodiment of a holder assembly.

FIG. 6 is a cross-sectional diagram of another embodiment of a holder assembly.

FIG. 7 is a cross-sectional diagram of an embodiment of a holder assembly and a pick.

FIG. 8 is a cross-sectional diagram of another embodiment of a holder assembly and a pick.

FIG. 9 is a cross-sectional diagram of another embodiment of a holder assembly and a pick.

FIG. 10 is a cross-sectional diagram of another embodiment of a holder assembly and a pick.

FIG. 11 is a cross-sectional diagram of another embodiment of a holder assembly and a pick.

FIG. 12 is a perspective diagram of an embodiment of a wedge.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENT

FIG. 1 is a cross-sectional diagram of an embodiment of a pavement milling machine 100. A plurality of holder assemblies 101 are attached to a rotating drum 102 connected to the underside of a pavement milling machine 100. The milling machine 100 may be a cold planer used to degrade man-made formations such as pavement 104 prior to the placement of a new layer of pavement. Holder assemblies 101 may be attached to the drum 102 at an angle, thereby bringing the holder assemblies 101 into engagement with the formation 104 at the desired level of aggressiveness. A pick 106 may be inserted into a holder assembly 101. As the drum 102 rotates in the direction shown by the arrows, the picks 106 temporarily contact the pavement 104. The impact from this contact causes the degradation of the pavement 104, as well as eventually wearing the picks 106. Drums 102 according to the present invention may also be used in mining machines, trenching machines, and in other applications.

FIG. 2 is a cross-sectional diagram of an embodiment of a holder assembly 101. The holder assembly 101 comprises a connection block 201 that has a block bore 202 which extends from a first opening 203 proximate a first end 205 of the assembly 101 to a second opening 204 proximate a second end 206 of the holder assembly 101. The block 201 is adapted for connection to a driving mechanism, such as a drum 102. In some embodiments the driving mechanism may be a milling drum connected to the underside of a pavement milling machine or another part of a milling machine. An extension element 207 is disposed in the block bore 202 and protrudes from the first opening 203 of the block bore 202. The extension element comprises a central extension bore 208 that has a longitudinal length 209. The block bore 202 may also comprise a longitudinal length 220. The central extension bore longitudinal length 209 may be at least as long as the block bore longitudinal length 220. An attachment mechanism 210 is disposed within the central extension bore 208 and is also disposed proximate the second end 206 of the holder assembly 101.

In the present embodiment the attachment mechanism 210 is inserted into the central extension bore 208 through the second opening 204 of the block bore 202. The central extension bore 208 of the extension element 207 comprises an opening 211 proximate the second end 206 of the holder assembly 101. The attachment mechanism 210 protrudes from the second opening 204 of the block bore 202. The attachment mechanism comprises a first set of threads 212 that are disposed on an outer surface 214 of the attachment mechanism 210. The first set of threads 212 corresponds with a second set of threads 213 that is disposed on an inner surface 215 of the central extension bore 208. By mating the first and second sets of threads 212, 213, the attachment mechanism 210 may be mechanically coupled to the extension element 207. In the present embodiment the attachment mechanism 210 is attached to the extension element 207 within the block bore 202 of the block 201.

Referring to FIGS. 2 and 3, with the attachment mechanism 210 mechanically coupled to the extension element 207, the attachment mechanism 210 may be considered to be interlocked with the extension element 207. Other types of interlocking between the attachment mechanism 210 and the extension element 207 may also be consistent with the present invention. FIG. 3 discloses a perspective diagram of an embodiment of an attachment mechanism 210 comprising a first set of threads 212 as previously discussed. The extension element 210 of FIG. 3 also comprises an external end 301. The external end 301 may protrude out of the second opening 204 of the block bore 202 and may interlock with or contact the block 201. The extension element 207 comprises a flange 216 proximate the first end 205 of the assembly 101. The flange 216 proximate the first end 205 may prevent the extension element 207 from further entering the block bore 202 by being too large to enter the block bore 202. This flange once abutted against the block will pull the extension element 207 towards it. The attachment mechanism 210 proximate the second end 206 may effectively attach the extension element 207 to the block 201 proximate the second end 206 and may thereby effectively prevent the extension element 207 from being removed from the second end 206 of the assembly 101. Together, the flange preventing the extension element 207 from further entering the block bore 202 and the attachment mechanism 210 preventing the extension element 207 from being removed from the second end 206 may make the extension element stationary in respect to the block 201. The extension element 207 is then attached to the block 201 via the attachment mechanism 210. In some embodiments an internal surface 217 of the block bore 202 may comprise an outwardly tapered surface 218. The outwardly tapered surface may allow the attachment mechanism 210 to hold the extension element 207 in attachment to the block 201.

FIG. 4 discloses a perspective view of an embodiment of an extension element 207 comprising a second set of threads 213 on an inner surface 215 of central extension bore 208. The extension element 207 also comprises slits 401 proximate the second end 206 of the assembly 101. When an attachment mechanism 210 is inserted into the opening 211 of the central extension bore 208, the attachment mechanism 210 may radially expand outward a portion of the extension element 207 proximate the slits 401. This expansion may cause the extension element 207 to engage the internal surface 217 of the block bore 202. In some such embodiments the attachment mechanism 210 may comprise a wedge.

FIGS. 5 and 6 disclose cross-sectional views of embodiments of holder assemblies 101 with the attachment mechanism 210 threaded into the extension element 207 and comprising a wedge 501. The wedge 501 of the attachment mechanism 210 is disposed within the extension central bore 208 of the extension element 207. The extension elements 207 comprise slits 401 proximate the second end 206 of the assembly. An extension element 207 may be forced to engage the internal surface 217 of the block bore 202 by the wedge 501 as the attachment mechanism 210 is threaded into the extension element 207. In FIG. 5 the attachment mechanism 210 comprises a hexagonally shaped receptacle 502. The hexagonal receptacle 502 may be adapted for use with a hex key, also known as a hex wrench or Allen wrench FIG. 6 discloses an embodiment in which the attachment mechanism 210 comprises an external end 602 that protrudes out of the second opening 204 of the block bore 202. The external end 602 contacts a surface 603 of the block 201 proximate the second end 206 of the assembly 101 when the attachment mechanism 210 is fully threaded into the extension element 207. In FIG. 6 the attachment mechanism 210 comprises a polygonal receptacle 601. The polygonal receptacle 601 may be adapted for use with a regular screw driver or some other generally flat, turnable device. In some embodiments the attachment mechanisms may comprise a receptacle adapted for use with a Phillips screwdriver or some other type of turnable device. In some embodiments, there is no receptacle. In such embodiments the external end may be adapted with wrench flats about its periphery or in other embodiments the attachment mechanism is adapted to be hand tightened. Further in the embodiment of FIG. 6, the external end 602 may abut against the connection block 201, thereby pulling down on the extension element 207 holding it snugly in place.

FIGS. 7-10 disclose embodiments of the invention in which a pick shank 701 is disposed within the central extension bore 208 and the pick shank 701 is connected to a wear-resistant impact tip 702. In each case a carbide bolster 703 is disposed intermediate the pick shank 701 and the impact tip 702 and is a means of connecting the pick shank 701 and the impact tip 702. In some embodiments the pick shank 701 and impact tip 702 may be connected to one another without an intermediate bolster 703. The impact tip 702 may comprise a superhard material with a hardness greater than 4000 HK. The superhard material may comprise a material selected from the group consisting of diamond, polycrystalline diamond, cubic boron nitride, refractory metal bonded diamond, silicon bonded diamond, layered diamond, infiltrated diamond, thermally stable diamond, natural diamond, vapor deposited diamond, physically deposited diamond, diamond impregnated matrix, diamond impregnated carbide, cemented metal carbide, chromium, titanium, aluminum, tungsten, or combinations thereof.

FIGS. 7-9 also disclose embodiments in which a lubricant reservoir 704 and a pick shank 701 are each disposed in the central extension bore 208. In FIG. 7 the lubricant reservoir 704 is disposed within the pick shank 701. In FIG. 8 the lubricant reservoir 704 is disposed within the central extension bore 208, partially within the pick shank 701 and partially outside of the pick shank 701. In both cases the lubricant reservoir 704 may comprise a pressurization mechanism 705 to pressurize the lubricant reservoir 704. In FIG. 7 the attachment mechanism 210 comprises an external end 602 that contacts the surface 603 of the block 201. The attachment mechanism 210 may be press fit into the central extension bore 208 of the extension element 207.

Referring now to FIG. 8, the extension element 207 comprises a plurality of coaxial central extension bores 208. The pick shank 701 and the lubricant reservoir 704 are each disposed in a primary central extension bore 706. The attachment mechanism 210 is at least partially disposed within a secondary central extension bore 707. The attachment mechanism 210 of FIG. 8 is adapted to interlock with the extension element 207. In some embodiments the attachment mechanism 210 may comprise a material having a characteristic of being biased towards the internal surface 217 of the block bore 202.

Referring now to FIG. 9, the carbide bolster 703 is press fit into a steel body 901 that is disposed intermediate the pick shank 701 and the bolster 703. The pick shank 701 and the lubricant reservoir 704 are disposed in the central extension bore 208 proximate the first end 205. An embodiment of an attachment mechanism 210 is disposed in the central extension bore 208 proximate the second end 206. A split ring 902 is disposed intermediate the inner surface 215 of the central extension bore 208 and the outer surface 214 of the attachment mechanism 210 proximate the second end 206 of the assembly 101. Pushing the attachment mechanism 210 into the split ring 902 may place an outward force on the extension element 207 which may push the extension element 207 outward to engage the connection block 201.

FIG. 10 discloses an embodiment of the invention in which the carbide bolster 703 protrudes into a cavity 1001 in the steel body 901 intermediate the shank 701 and the impact tip 702. FIG. 10 also discloses an embodiment in which the attachment mechanism 210 is press fit into the central extension bore 208 from the second end 206 of the holder assembly 101. This may force the extension element 207 to engage the connection block 201 proximate the second end 206.

Referring now to FIGS. 11 and 12, an embodiment of a holder assembly 101 is disclosed in which the outer surface 214 of the attachment mechanism 210 comprises ridges 1101. In the embodiment of FIG. 11, a secondary central extension bore 707 comprises recesses 1102 into which the ridges 1101 of the attachment mechanism 210 may interlock. As shown in the FIG. 12, the attachment mechanism 210 may comprise a wedge 501. FIG. 11 also discloses an embodiment of the invention in which the carbide bolster 703 is brazed to the steel body 903 at a planar interface 1103.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.

Claims

1. A holder assembly, comprising: a connection block comprising a block bore extending from a first opening proximate a first end of the assembly to a second opening proximate a second end of the assembly; the block being adapted for connection to a driving mechanism; an extension element disposed in the block bore and protruding from the first opening of the block bore; the extension element comprising a central extension bore comprising a longitudinal length; and an attachment mechanism disposed within the central extension bore and being disposed proximate the second end of the assembly.

2. The holder assembly of claim 1, wherein the attachment mechanism attaches to the extension element within the block bore of the block.

3. The holder assembly of claim 1, wherein the block and the extension element are attached to one another via the attachment mechanism.

4. The holder assembly of claim 1, wherein the attachment mechanism radially expands at least a portion of the extension element outward to engage an inner surface of the block bore.

5. The holder assembly of claim 4, wherein the attachment mechanism comprises a wedge.

6. The holder assembly of claim 1, wherein an external surface of the attachment mechanism comprises ridges.

7. The holder assembly of claim 1, wherein the attachment mechanism is inserted into the central extension bore through the second opening of the block bore.

8. The holder assembly of claim 1, wherein the attachment mechanism is adapted to interlock with the extension element.

9. The holder assembly of claim 1, wherein the longitudinal length of the central extension bore is at least as long as a longitudinal length of the block bore.

10. The holder assembly of claim 1, wherein the central extension bore of the extension element comprises an opening proximate the second end of the assembly.

11. The holder assembly of claim 1, wherein the extension element comprises a plurality of coaxial central extension bores.

12. The holder assembly of claim 11, wherein a lubricant reservoir and a pick shank are each disposed in the primary central extension bore.

13. The holder assembly of claim 1, wherein an internal surface of the block bore comprises outwardly tapered surfaces.

14. The holder assembly of claim 1, wherein an external surface of the attachment mechanism comprises a first set of threads that corresponds to a second set of threads disposed on an inner surface of the central extension bore.

15. The holder assembly of claim 1, wherein a split ring is disposed intermediate the inner surface of the central extension bore and an external surface of the extension element proximate the second end of the assembly.

16. The holder assembly of claim 1, wherein the extension element comprises slits proximate the second end of the assembly.

17. The holder assembly of claim 1, wherein the attachment mechanism protrudes from the second opening of the block bore.

18. The holder assembly of claim 1, wherein the attachment mechanism comprises an external end that protrudes out of the second opening of the block bore and contacts a surface of the block proximate the second end of the assembly.

19. The holder assembly of claim 1, wherein a pick shank is disposed within the central extension bore and the pick shank is connected to a wear-resistant impact tip.

20. The holder assembly of claim 1, wherein the driving mechanism is a milling drum connected to the underside of a pavement milling machine or part of a milling machine.