초록 ▼

An improved bit holder with its mating bit block is disclosed utilizing a slight taper in the bit block bore, and a tapered shank on the bit holder that includes a second larger diameter tapered distal segment that combines with an axially oriented slot through the side wall of the bit holder shank

An improved bit holder with its mating bit block is disclosed utilizing a slight taper in the bit block bore, and a tapered shank on the bit holder that includes a second larger diameter tapered distal segment that combines with an axially oriented slot through the side wall of the bit holder shank to allow a substantially larger interference fit between the distal tapered shank segment and the bit block bore than previously known. When inserting the bit holder in the bit block bore, the distal first tapered segment resiliently collapses to allow insertion of that segment into the bit block bore. A second shank tapered portion axially inwardly of the first distal tapered portion. The dual tapered shank allows the insertion of the bit holder in the bit block with an interference fit that provides a secure mounting of the bit holder in the bit block.

대표청구항 ▼

1. In an assembly for use in road milling, trenching and mining equipment including a bit, said bit holder and a bit block, said bit being mountable in a first bore through said bit holder and said bit holder being mountable in a second bore through said bit block, said bit holder and bit block, in

1. In an assembly for use in road milling, trenching and mining equipment including a bit, said bit holder and a bit block, said bit being mountable in a first bore through said bit holder and said bit holder being mountable in a second bore through said bit block, said bit holder and bit block, in combination, comprising: a generally frustoconical bit holder front portion terminating at an annular flange and a generally cylindrical bit holder shank portion extending axially rearwardly from said annular flange defining an annular sidewall, an elongate slot radially through said sidewall extending axially from a distal end of said shank and terminating between said distal end and said front portion defining a C-shape portion of said shank, an outer surface of said C-shape portion providing interference with said second bore on said bit block sufficient to maintain said bit holder on said bit block during use. 2. The assembly as defined in claim 1 wherein said C-shape portion of said shank is resiliently collapsible diametrically for providing said interference with said bit block bore. 3. The assembly as defined in claim 1 wherein said C-shape portion of said shank is resiliently collapsible when said bit holder is mounted on said bit block for absorbing radial forces directed to said bit holder. 4. The assembly as defined in claim 1 wherein said shank outer diameter adjacent said front portion annular flange is smaller than said bit block axial bore adjacent a top face of said bit block for allowing resilient absorption of radial forces directed to said bit holder. 5. The assembly as defined in claim 1 wherein said interference is greater than a standard press fit. 6. A bit holder for use in road milling, trenching and mining equipment as part of an assembly including a bit, said bit holder and a bit block, said bit being mountable in a first bore through said bit holder and said bit holder being mountable in a second bore through said bit block, said bit holder comprising: a generally frustoconical front portion terminating at an annular flange and at least one generally cylindrical shank portion extending axially rearwardly from said annular flange defining an annular sidewall, an elongate slot radially through said sidewall extending axially from a distal end of said shank and terminating between said distal end and said front portion defining at least one angular segment of said shank being less than 360 degrees in circumferential length, an outer surface of said angular segment providing interference with said second bore on said bit block sufficient to maintain said bit holder in said bit block during use. 7. The bit holder as defined in claim 6 wherein said angular segment of said shank is resiliently collapsible diametrically for providing said interference with said bit block bore. 8. The bit holder as defined in claim 6 wherein said angular segment of said shank is resiliently collapsible when said bit holder is mounted on said bit block for absorbing radial forces directed to said bit holder. 9. The bit holder as defined in claim 6 wherein said shank outer diameter adjacent said front portion annular flange is smaller than said bit block axial bore adjacent a top face of said bit block for allowing resilient absorption of radial forces directed to said bit holder. 10. The bit holder as defined in claim 6 wherein said interference is greater than a standard press fit. 11. A bit holder for use in road milling, trenching and mining equipment as part of an assembly including a bit, said bit holder and a bit block, said bit being mountable in a first bore through said bit holder and said bit holder being mountable in a second bore through said bit block, said bit holder comprising: a generally frustoconical front portion terminating at an annular flange and a generally cylindrical shank portion extending axially rearwardly from said annular flange defining an annular sidewall, an elongate slot radially through said sidewall extending axially from a distal end of said shank and terminating between said distal end and said front portion defining a C-shape portion of said shank, an outer surface of said C-shape portion providing interference with said second bore on said bit block sufficient to maintain said bit holder in said bit block during use. 12. The bit holder as defined in claim 11 wherein said C-shape portion of said shank is resiliently collapsible diametrically for providing said interference with said bit block bore. 13. The bit holder as defined in claim 11 wherein said C-shape portion of said shank is resiliently collapsible when said bit holder is mounted on said bit block for absorbing radial forces directed to said bit holder. 14. The bit holder as defined in claim 11 wherein said shank outer diameter adjacent said front portion annular flange is smaller than said bit block axial bore adjacent a top face of said bit block for allowing resilient absorption of radial forces directed to said bit holder. 15. The bit holder as defined in claim 11 wherein said interference is greater than a standard press fit. 16. The bit holder as defined in claim 1, wherein said bit holder further includes a means disposed in said front portion of said bit holder beginning adjacent a front face thereof to enable quick removal of said bit. 17. The bit holder as defined in claim 16, wherein said means is at least one of one of a notch, flat and detent. 18. The bit holder as defined in claim 17, wherein said at least one of said one of a notch, flat and detent is a notch. 19. The bit holder as defined in claim 18, wherein said bit holder includes a predetermined plurality of notches. 20. The bit holder as defined in claim 19, wherein said predetermined plurality of notches is at least two. 21. The bit holder as defined in claim 19, where said predetermined plurality of notches is at least three. 22. The bit holder as defined in claim 21, wherein said three notches are positioned at about 120° apart. 23. The bit holder as defined in claim 19, where said predetermined plurality of notches is at least four. 24. The bit holder as defined in claim 23, wherein said four notches are positioned at from 90° apart. 25. The assembly as defined in claim 1 wherein said interference extends from about 0.005 to 0.012 inch in a portion of said shank including said elongate slot.