Non-rotating chisel for a cutting tool

Abstract

A cutting tool arrangement (500) for attachment to a tool holder (110) of a milling machine, comprising a cutting tip (510), a generally cylindrical shank (520) extending from the cutting tip (510), a spring clip (560) surrounding a body (522) of the shank (520) and having a contracted configuration and an expanded configuration, and a washer (590) with an installed configuration in which the washer (590) is arranged on a shoulder (528) of the shank (520), and a non-installed configuration in which the washer (590) surrounds the spring clip (560) and holds the spring clip (560) in the contracted configuration. At least one distal edge (566) of the spring clip (560) or proximal edge (592) of a bore (591) of the washer (590) has a chamfer or radius.

Description

Technical area

[0001] The present disclosure relates generally to bits for cutting tools and, more particularly, to a non-rotating bit assembly for a tool holder of a milling machine, such as a cold milling machine or a rotary mixer. State of the art

[0002] Asphalt roadways facilitate vehicular traffic. Depending on traffic density, subsurface conditions, temperature variation, moisture variation, and / or physical age, the roadway surface can eventually become misshapen, uneven, unable to support wheel loads, or otherwise unsuitable for vehicular movement. To rehabilitate roadways for continued vehicular use, the worn road surface (e.g., asphalt or concrete) is removed in preparation for resurfacing.

[0003] Cold planers, sometimes called road milling machines or rippers, typically contain a frame supported by track or wheel drives. The frame is configured to house an engine, operator station, and a milling drum. The milling drum, equipped with cutting tools, is rotated by the engine via a suitable interface to break up the road surface. In a typical configuration, multiple cutting tools are mounted on an outer surface of the milling drum. The cutting tools are usually attached to the tool holders in a manner that allows the cutting tools to rotate freely during operation.

[0004] However, cutting bit rotation has some notable disadvantages. For certain bits, such as those with polycrystalline diamond (PCD) tips, cutting bit rotation causes wear on all sides of the bit, reducing bit strength. Furthermore, cutting tool rotation can cause wear and, consequently, reduced toolholder life. For example, cutting bit rotation can cause wear on the face and internal bore of the toolholder (which is contacted by the cutting bit), making the toolholder less effective or unable to hold cutting bits.

[0005] U.S. Patent No. 8,646,848 to Hall et al. (hereinafter "the '848 patent") discloses a pick assembly including a pick shank configured to be press-fitted directly into a bore of a block. The pick shank includes an inner and an outer surface, and the pick includes a pick head opposite the shank. The shank includes at least one elongated recess extending from a distal end of the shank along the shank toward the pick head. The recess allows the shank to resiliently contract upon insertion into the bore while maintaining an interference fit between the bore and the shank. The shank additionally has tapered portions that engage an interference fit with a corresponding tapered portion of the bore of the block.

[0006] The '848 patent requires a block with a non-standard, tapered bore.

[0007] Therefore, the pick shaft cannot be used as a universal replacement without first retrofitting the cutting machine with the required conical block.

[0008] The cutting bit assembly of the present disclosure solves one or more of the problems set forth above and / or other problems in the art. Brief description

[0009] One aspect of the present disclosure relates to a cutting bit assembly for attachment to a tool holder of a milling machine, including: a cutting tip, a generally cylindrical shank extending from the cutting tip, a spring clip surrounding a body of the shank and having a contracted configuration and an expanded configuration, and a washer having an installed configuration in which the washer is disposed on a shoulder of the shank and an uninstalled configuration in which the washer surrounds the spring clip and maintains the spring clip in the contracted configuration. At least one of a distal edge of the spring clip or a proximal edge of a bore of the washer has a chamfer or a radius.

[0010] In another aspect, a method for removing a cutting bit assembly from a tool holder of a milling machine, the cutting bit assembly including a spring clip that engages a mounting bore of the tool holder, includes sliding a shank of the cutting bit assembly out of the mounting bore of the tool holder, and sliding a washer from a shoulder of the shank over the spring clip while sliding the shank out of the mounting bore to hold the spring clip in a contracted configuration.

[0011] In another aspect, a washer for a cutting bit assembly of a milling machine comprises an annular structure defining a bore extending along a longitudinal axis, a chamfered outer distal edge of the annular structure, a chamfered proximal edge of the bore, a chamfered distal edge of the bore, and a vertical sidewall of the bore between the proximal edge of the bore and the distal edge of the bore. Short description of the drawings

[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and, together with the description, serve to explain the principles of the disclosed embodiments. Fig. 1 is an exploded view of a cutting tool of a cold milling machine according to aspects of the present disclosure. Fig. 2 is a perspective view of a cutting bit according to aspects of the present disclosure. Fig. 3 is a perspective view of a cutting bit assembly including the cutting bit of Fig. 2, according to aspects of the present disclosure. Fig. 4 is a perspective view of a spring clip of the cutting bit of Fig. 3. Fig. 5 is a cross-sectional view of the spring clip of Fig. 4, taken along line 5-5. Fig. 6 is a cross-sectional view of the cutting bit of Fig. 3, taken along line 6-6. Fig. 7 is a perspective view of an alternative cutting bit according to aspects of the present disclosure. Fig. Figure 8 is a side elevation view of a cutting bit assembly showing the cutting bit of Fig. 7, according to aspects of the present disclosure. Fig. 9A is a perspective view of a spring clip of the cutting bit of Fig. 8. Fig. 9B is a perspective view of an alternative spring clip according to aspects of the present disclosure. Fig. 10 is a cross-sectional view of the cutting bit of Fig. 8, taken along line 10-10. Fig. 11 is a perspective view of yet another cutting bit according to aspects of the present disclosure. Fig. 12 is a side view of a cutting bit assembly including the cutting bit of Fig. 11, according to aspects of the present disclosure. Fig. 13 is a cross-sectional view of the cutting bit of Fig. 12, taken along line 13-13, according to aspects of the present disclosure. Fig. 14 is a cross-sectional view of the cutting bit assembly of Fig. 12, taken along line 14-14. Fig. 15 is a cross-sectional view of another cutting bit assembly according to aspects of the present disclosure. Fig. 16 is a cross-sectional view of another cutting bit assembly according to aspects of the present disclosure. Fig. 17 illustrates a flowchart showing an exemplary method for installing a cutting bit assembly in a tool holder according to aspects of the present disclosure. Fig. 18 illustrates a flowchart showing an exemplary method for removing a cutting bit assembly from a tool holder according to aspects of the present disclosure. Fig. 19 is a cross-sectional view of a cutting bit assembly according to aspects of the present disclosure with a washer in an installed position. Fig. 20 is a cross-sectional view of the cutting bit assembly of Fig. 19 with the washer in a pre- or post-installed position. Fig. 21 is a cross-sectional view of detail 21 of the cutting bit assembly of Fig. 20 Fig. 22 is a plan view of the washer of Fig. 19. Fig. 23 is a side cross-sectional view of the washer of Fig. 19, taken along line 23-23 from Fig. 22. Fig. 24 is a cross-sectional view of detail 24 of the washer of Fig. 23. Detailed description

[0013] Both the foregoing general description and the following detailed description are exemplary and explanatory only and do not limit the features as claimed. As used herein, the terms "comprises," "comprising," "having," "comprising," "includes," "containing," "containing," "limited," or other variations thereof are intended to cover non-exclusive inclusion such that a process, method, article, or apparatus comprising a list of elements does not include only those elements, but may include other elements not expressly listed or inherent in such process, method, article, or apparatus. In this disclosure, relative terms such as "about," "substantially," and "approximately" are used to indicate a possible deviation of ±10% of the stated value unless otherwise noted.In the accompanying drawings, like reference numerals refer to like components.

[0014] Referring to Fig. 1, a cold planer or other milling machine (e.g., a rotary mixer) includes a milling drum 100, which is a generally cylindrical, rotating structure for cutting and grinding a substrate, such as road asphalt. The milling drum 100 has an outer surface 102 upon which a plurality of tool assemblies 104 are laid out. Each tool assembly 104 includes a tool mounting block 108, a tool holder 110, and a cutting bit assembly 200. The tool assemblies 104 may be configured such that rotation of the milling drum 100 causes the cutting bit assembly 200 of each tool assembly 104 to break up and remove the material from the road surface and direct it to a collection device (not shown). Fig. Although only a single tool assembly 104 is shown in Figure 1, the milling drum 100 may include multiple tool assemblies 104 arranged in a series of rows, rings, spirals, etc. on the outer surface 102.

[0015] For each tool assembly 104, the tool mounting block 108 can be attached to the outer surface 102 of the milling drum, e.g., by welding, and is configured to removably receive the tool holder 110 in a mounting bore 114 of a mounting portion 116. The tool holder 110 includes an end face 120 and a mounting bore 122 configured to removably receive the cutting bit assembly 200. The mounting bore 122 can have an inner diameter of, e.g., 20 millimeters (mm). With further reference to Fig. 1 and with further reference to Fig. 2 and Fig. 3, the cutting bit assembly 200 includes a cutting tip 210 and a shank 220 extending from the cutting tip 210. The cutting tip 210 may be substantially conical and have a substantially pointed distal end 212 that tapers radially outward to form a flange 214 from which the shank 220 extends. The flange 214 may have a diameter of about 42-48 mm, in some cases about 45 mm. In some cases, the distal end 212 includes a polycrystalline diamond tip for milling the substrate, although other abrasive materials may alternatively be used.

[0016] With further reference to Fig. 2, the shank 220 includes a body 222, a shoulder 228 between the body 222 and the flange 214, and a proximal end 224. The body 222 of the shank 220 is generally cylindrical, except for the rotation limiting surface 230 described below. The shoulder 228 is generally cylindrical and extends 360° around the body 222. The shoulder 228 may have an outer diameter slightly less than the diameter of the mounting bore 122 of the tool holder 110 such that the shoulder 228 has a clearance fit with the mounting bore 122. For example, the shoulder 228 may have an outer diameter of slightly less than 20 mm. The shoulder 228 may extend longitudinally of the flange 214 about 3-12 mm, and in some cases about 5 mm. The proximal end 224 may be generally cylindrical, except for the notch 226, as described below.The proximal end 224 may have an outer diameter slightly smaller than the diameter of the mounting hole 122 of the tool holder 110, such that the proximal end 224 has a clearance fit with the mounting hole 122. For example, the proximal end 224 may have an outer diameter of slightly less than 20 mm. The proximal end 224 may have a length of approximately 5-15 mm, and in some cases, approximately 10 mm.

[0017] The body 222 of the shaft 220 has an outer diameter that is smaller than that of the shoulder 228 and the proximal end 224, for example, a diameter of about 10-36 mm, and in some aspects, about 14 mm. The body 222 of the shaft 220 may have a length, i.e., the distance between the shoulder 228 and the proximal end 224, of about 25-50 mm, and in some aspects, about 35 mm. The shaft 220, including the body 222, the proximal end 224, and the shoulder 228, may be made of a strong, rigid material such as a heat-treatable steel (e.g., AISI 1040 steel).

[0018] As in the Fig. 1 and Fig. As shown in Figure 3, the body 222 is at least partially surrounded by a spring clip 260 that can be elastically deflected between a contracted (or tensioned) configuration and an expanded (or untensioned) configuration. The spring clip 260 may be made of a material, such as spring steel, that imparts elasticity to the spring clip 260.

[0019] The elasticity of the spring clip 260 is such that the spring clip 260 is in the expanded configuration when there is no external constraint. In the expanded configuration, the outer diameter of the spring clip 260 is larger than the inner diameter of the mounting hole 122 of the tool holder 110. In the contracted configuration, the outer diameter of the spring clip 260 is smaller than in the expanded configuration to allow the spring clip 260 to be inserted into the mounting hole 122 of the tool holder 110. The outer diameter of the spring clip 260 in the contracted configuration is slightly larger than the inner diameter of the mounting hole 122, creating a slight interference fit between the mounting hole 122 and the spring clip 260 in the contracted configuration. For example, the outer diameter of the spring clip 260 in the contracted configuration may be slightly larger than 20 mm.In some cases, the outer surface of the spring clip 260 may have a surface treatment to increase friction with the mounting hole 122.

[0020] Referring to Fig. 3, the cutting bit assembly 200 further includes a washer 290 surrounding the spring clip 260 and holding the spring clip 260 in the contracted configuration on the body 222 of the shaft 220. The washer 290 is generally flat and annular and has an outer diameter and a bore concentric with the outer diameter. The washer 290 may have an outer diameter approximately equal to the outer diameter of the flange 214. The washer 290 may have a thickness of approximately 3-8 mm and, in some cases, approximately 5 mm. The bore of the washer 290 has a diameter equal to the outer diameter of the spring clip 260 in the contracted configuration. The proximal edge 292 and the distal edge (in Fig. 3) of the bore of washer 290 may be chamfered to facilitate installation, removal, and / or reuse of bit assembly 200, as described below. Similarly, the proximal edge 296 and distal edge 298 of the outer diameter of washer 290 may be chamfered to facilitate installation, removal, and / or reuse of bit assembly 200 (see below).

[0021] The preload of the spring clip 260 acts against the bore of the washer 290, resulting in a frictional engagement that holds the washer 290 in its axial position on the spring clip 260. When the cutting bit assembly 200 is inserted into the mounting bore 122 of the tool holder 110 (see Fig. 1), the washer 290 is pushed onto the shoulder 228 and into contact with the flange 214 (up to the Fig. 12 and Fig. 14). The chamfer on the distal edge of the bore of washer 290 can guide washer 290 onto shoulder 228.

[0022] With reference to Fig. 2 and Fig. 3, the proximal end 224 of the shaft 220 can hold the spring clip 260 axially against the body 222 of the shaft 220. In the expanded configuration, the spring clip 260 can have an inner diameter greater than or equal to the outer diameter of the proximal end 224 so that the spring clip 260 can be slid over the proximal end 224 to install the spring clip 260 onto the body 222 of the shaft 220. The washer 290 can be installed after the spring clip 260 has been slid onto the body 222 of the shaft 200. The washer 290 forces the spring clip 260 into the contracted configuration in which the inner diameter of the spring clip 260 is smaller than the outer diameter of the proximal end 224 of the shaft 220. Therefore, the spring clip 260 cannot slide over the proximal end 224 when it is in the contracted configuration.Similarly, the inner diameter of the spring clip 260 in the contracted configuration is smaller than the outer diameter of the shoulder 228, so that the spring clip 260 cannot slide over the shoulder 228 in the contracted configuration. Thus, the spring clip 260 is held captive between the shoulder 228 and the proximal end 224.

[0023] With further reference to Fig. 2, the shaft 220 includes a rotation limiting surface 230 configured to cooperate with the spring clip 260 to limit the rotation between the shaft 220 and the spring clip 260. In the Fig. 2, the rotation limiting surface 230 includes a first planar surface 232 and a second planar surface 234. The first planar surface 232 and the second planar surface 234 may be recessed into the body 222 of the shaft 220 and may be adjacent to each other and at an angle α (see Fig. 6) relative to each other. The angle α may be about 135-145°, and in some aspects about 140°. In some aspects (not shown), the first and second planar surfaces 232, 234 may be spaced apart from each other. Each of the first and second planar surfaces 232, 234 may be substantially rectangular and have a length (along the longitudinal axis of the shaft 220) of about 17-37 mm, and in some aspects about 27 mm, and a width (transverse to the longitudinal axis of the shaft 220) of about 5-10 mm, and in some aspects about 7 mm. In other aspects, the first and second planar surfaces 232, 234 may have shapes other than rectangular, e.g., pill-shaped, oval, trapezoidal, hexagonal, or the like.

[0024] In some aspects, each of the first and second planar surfaces 232, 234 may be spaced from the shoulder 228 by about 2-8 mm, and in some aspects by about 5 mm. In some aspects, each of the first and second planar surfaces 232, 234 may be spaced from the proximal end 224 by about 5-16 mm, and in some aspects by about 12 mm.

[0025] Referring to Fig. 3-6, the spring clip 260 extends along a longitudinal axis 262 and has a generally tubular shape (except for the projections 270, 280). The spring clip 260 includes a slot 264 extending from a proximal end to a distal end to allow the spring clip 260 to transition between the contracted configuration and the expanded configuration. In particular, the slot 264 is narrower in the contracted configuration of the spring clip 260 than in the expanded configuration of the spring clip 260. In some cases, a distal edge 266 of the spring clip 260 may be beveled. In some cases, the wall thickness of the spring clip 260 may be between about 1.50 mm and 1.75 mm.

[0026] The spring clip 260 includes one or more internal projections extending radially inward from the inner diameter toward the longitudinal axis 262. In the Fig. 3-6, the spring clip 260 includes two projections 270 and 280 spaced apart along the longitudinal axis 262. The projections 270, 280 may be formed by a stamping operation such that the projections 270, 280 are pressed into the sidewall of the spring clip 260. In other cases, the projections 270, 280 may include material added to the inner sidewall of the spring clip 260. The projection 270 includes a third planar surface 272 and a fourth planar surface 274. The third planar surface 272 and the fourth planar surface 274 may be configured at an angle β to each other (see Fig. 5). The angle β may be about 136-156°, and in some aspects, about 146°. Each of the third and fourth planar surfaces 272, 274 may be substantially rectangular and have a length (along the longitudinal axis of the shaft 220) of about 7-17 mm, and in some aspects, about 11 mm, and a width (transverse to the longitudinal axis of the shaft 220) of about 4-8 mm, and in some aspects, about 6 mm. The total length of the protrusions, including both the third and fourth planar surfaces 272, 274 of the protrusion 270 and the analogous planar surfaces of the protrusion 280, may be about 8-35 mm, and in some aspects, about 27 mm. In other aspects, the third and fourth planar surfaces 272, 274 may have shapes other than rectangular, e.g., pill-shaped, oval, trapezoidal, hexagonal, or the like.

[0027] As in Fig. 6, the projection 270 of the spring clip 260 interacts with the rotation limiting surface 230 of the shaft 220 to limit the rotation of the shaft 220 relative to the spring clip 260 in both the contracted and expanded configurations of the spring clip 260. Specifically, the third planar surface 272 of the spring clip 260 is configured to engage the first planar surface 232 of the rotation limiting surface 230 of the shaft 220 to limit the clockwise rotation of the shaft 220 within the spring clip 260. Similarly, the fourth flat surface 274 of the spring clip 260 is configured to engage the second flat surface 234 of the rotation limiting surface 230 of the shaft 220 to limit the counterclockwise rotation of the shaft 220 within the spring clip 260.

[0028] In some cases, the angle β of the projection 270 of the spring clip 260 is greater than the angle α of the rotation limiting surface 230 of the shaft 220. Therefore, an angular gap θ exists between the first flat surface 232 and the third flat surface 272 and / or between the second flat surface 234 and the fourth flat surface 274. The angular gap θ allows limited rotation of the shaft 220 within the spring clip 260. The shaft 220 can be rotated clockwise within the spring clip 260 until the first flat surface 232 of the rotation limiting surface 230 engages the third flat surface 272 of the projection 270. Similarly, the shaft 220 can be rotated counterclockwise 52 within the spring clip 260 until the second flat surface 234 of the rotation limiting surface 230 engages the fourth flat surface 274 of the projection 270.

[0029] The angle β of the projection 270 of the spring clip 260 may be larger when the spring clip 260 is in the extended configuration compared to the retracted configuration due to the overall expansion of the spring clip 260. Therefore, the shaft 220 may have less rotational freedom relative to the spring clip 260 when the spring clip 260 is in the contracted configuration than when the spring clip 260 is in the expanded configuration.

[0030] The projection 280 may be substantially identical to the projection 270 and include a third planar surface and a fourth planar surface corresponding to the third planar surface 272 and the fourth planar surface 274, respectively. The projections 270 and 280 may be separated by a rib 275 that provides rigidity to the spring clip 260 and resists its deformation. In some cases, the spring clip 260 may include only a single projection 270, with the rib 275 absent.

[0031] In order to accommodate the projections 270 and 280, the proximal end 224 of the shaft 220 (see Fig. 2) a notch 226 that provides clearance for the projections 270, 280 to slide over the proximal end 224 onto the body 222 of the shaft 220 when the spring clip 260 is installed on the shaft 220. The notch 226 is shaped to receive the projections 270, 280. Thus, the notch 226 may include two flat surfaces that allow the third flat surface 272 and the fourth flat surface 274 of the projection 270 (along with the corresponding surfaces of the projection 280) to slide over the proximal end 224.

[0032] Fig. 7, Fig. 8, Fig. 9A and Fig. 10 illustrate another aspect of the cutting bit assembly 300 according to the present disclosure, wherein the corresponding components of the cutting bit assembly 200 are represented by the number 100 added to the reference number. Of the components not specifically related to Fig. 7-10, it can essentially be assumed that they are similar to the corresponding components of the aspect in Fig. 2-6 are. The cutting tip 310 of the aspect of Fig. 7, Fig. 8 and Fig. 10 may be substantially identical to the cutting tip 210 of Fig. 2-6. As in Fig. 7, the rotation limiting surface 330 of the body 322 of the shaft 320 includes a groove 336 recessed into the body 322. The groove 336 may be about 17-37 mm long, in some aspects about 27 mm long, and about 8-15 mm wide, in some aspects about 12 mm wide. The groove 336 may be recessed into the body 322 of the shaft 320 by about 1-5 mm relative to the outer diameter of the body 322, and in some aspects by about 2 mm relative to the outer diameter of the body 322. The groove 336 may be spaced from the shoulder 328 by about 2-8 mm, and in some cases about 5 mm. The groove 336 may be spaced from the proximal end 324 by about 5-16 mm, and in some aspects about 12 mm.

[0033] As in Fig. 8, Fig. 9A and Fig. 10, the projection 370 of the spring clip 360 includes tabs 376 that extend radially inward toward the longitudinal axis 362. The illustrated aspect includes two tabs 376, although any number of tabs (e.g., one, two, three, four, etc.) may be used. The tabs 376 may be formed, for example, by a stamping process to bend the tabs 376 inward. The tabs 376 may, as illustrated, be generally symmetrical, but need not be. The tabs 376 may have a length (in a direction parallel to the longitudinal axis of the shaft 320) of about 4-10 mm, in some cases about 7 mm. The tabs 376 may extend inward from the inner sidewall of the spring clip 360 by about 1-4 mm, and in some aspects by about 2 mm. The projection 380 may be substantially identical to the projection 370. In some embodiments, the spring clip 360 may include only a single protrusion 370.

[0034] As in Fig. 10, the tabs 376 interact with the rotation limiting surface 330 in both the contracted and expanded configurations of the spring clip 360 to limit the rotation of the shaft 320 within the spring clip 360. In particular, the tabs 376 extend into the groove 336 of the shaft 320 such that rotation of the shaft 320 causes the tabs to engage the side walls 338 of the groove 336. In some cases, as in Fig. 10, the clearance between the tabs 376 and the side walls 338 is negligible, so that rotation of the shaft 320 relative to the spring clip 360 is limited or impossible. In other cases, there may be clearance between the tabs 376 and the side walls 338, allowing limited, predetermined rotation of the shaft 320 relative to the spring clip 360.

[0035] As in Fig. 7 and Fig. 8, the notch 326 in the proximal end 324 of the shaft 320 may include a single flat surface to allow the tabs 376 to clear the proximal end 324 when the spring clip 360 is installed on the shaft 320.

[0036] As in Fig. 8, the washer 390 holds the spring clip 360 in the contracted configuration in the same manner as described herein in connection with the aspect of Fig. 2-6 is described.

[0037] Fig. 9B illustrates another aspect of the spring clip 360. The spring clip 360 in Fig. 9B includes a single projection, namely projection 370, which may extend substantially the entire length of spring clip 360. Projection 370 includes a tab 377 extending radially to longitudinal axis 362. Tab 377 may be formed by rolling or bending one of the edges of spring clip 360 on either side of slot 364. Tab 377 fits into groove 336 of shaft 320 (see Fig. 10) in substantially the same manner as the tabs 376 of the aspect of Fig. 9A, and the tab 377 engages the side walls 338 of the groove 336 to limit or prevent rotation of the shaft 320 relative to the spring clip 360. Since the aspect of Fig. 9B contains only a single tab 377, the groove 336 of the shaft 320 may be narrower than in Fig. 10 to limit the clearance between the tab 377 and the sidewalls 338 of the groove 336. Additionally, the groove 336 may extend substantially the entire length of the body 322 of the shaft 320 to receive the tab 377, which extends substantially the entire length of the spring clip 360. That is, the groove 336 may extend substantially the entire distance between the proximal end 324 and the shoulder 328. In other aspects (not shown), both edges of the spring clip on either side of the slot 364 may be shaped into a tab, and the groove 336 of the shaft 320 may be wide enough to accommodate two tabs.

[0038] Fig. 11-14 illustrate another aspect of the cutting bit assembly 400 according to the present disclosure, wherein the corresponding components of the cutting bit assembly 200 are represented by the number 200 added to the reference number. Of the components not specifically related to Fig. 11-14, it can essentially be assumed that they are similar to the corresponding components of the aspect in Fig. 2-6 are. The cutting tip 410 of the aspect of Fig. 11-14 may be substantially identical to the cutting tip 210 of Fig. 2-6. As in Fig. 11 and Fig. 13, the rotation limiting surface 430 may include a single flat surface 440 recessed into the body 422. The flat surface 440 may be about 17-37 mm long, in some aspects about 27 mm long, and about 13-16 mm wide, in some aspects about 15 mm wide. The flat surface 440 may be recessed into the body 422 of the shaft 420 by about 2-6 mm relative to the outer diameter of the body 422, and in some aspects by about 4 mm relative to the outer diameter of the body 422. The flat surface 440 may be spaced from the shoulder 428 by about 2-8 mm, and in some cases by about 5 mm. The flat surface 440 may be spaced from the proximal end 424 by about 5-16 mm, and in some aspects by about 12 mm. The flat surface 440 may extend partially around the circumference of the body 422 of the shaft 420, e.g., about 99-139° around the circumference of the body 422, and in some aspects about 119° around the circumference of the body 422.

[0039] As in Fig. 13-14, the cutting bit assembly 400 also includes a pin 450 clamped between the spring clip 460 and the rotation limiting surface 430 of the shank 420. The pin 450 is generally cylindrical and oriented parallel to the longitudinal axis of the spring clip 460.

[0040] The pin 450 may have a length of approximately 15-35 mm, in some cases approximately 25 mm, and a diameter of approximately 1-5 mm, in some cases approximately 3 mm. The spring clip 460 may include an inspection port 468 that allows a view of the pin 450 through the spring clip 460, allowing an operator / installer to verify that the pin 450 is properly seated between the spring clip 460 and the flat surface 440 of the shaft 420 before and / or during installation of the cutting bit assembly 400 in the milling drum 100.

[0041] As in Fig. As shown in Figures 12 through 14, the projections 470, 480 of the spring clip 460 retain the pin 450 in position on the flat surface 440. The projections 470, 480 interact with the rotation limiting surface 450 through the pin 450 in both the contracted and expanded configurations of the spring clip 460 to limit the rotation of the shaft 420 within the spring clip 460. The projection 470 includes one or more notches 478 extending radially inward to retain the pin 450 laterally on the flat surface 440 of the rotation limiting surface 430. Attempting to rotate the shaft 420 relative to the spring clip 460 causes the notches 478 to press the pin 450 against the flat surface 440, thus limiting the rotation of the shaft 420 relative to the spring clip 460. In various aspects, the notches 478 may be curved, as shown in Fig. 14, or they may be substantially flat. Each of the notches 478 may be substantially rectangular and have a length (along the longitudinal axis of the shaft 420) of about 6-25 mm, and in some aspects about 8 mm, and a width (transverse to the longitudinal axis of the shaft 420) of about 3-7 mm, and in some aspects about 5 mm. In other aspects, the notches 478 may have shapes other than rectangular, e.g., pill-shaped, oval, trapezoidal, hexagonal, or the like.

[0042] Fig. 12 and Fig. 14 show the washer 490 arranged around the shoulder 428 of the shank 420, this is the position of the washer 490 when the cutting bit assembly 400 is mounted in the mounting bore 122 of the tool holder 110. Before installation in the tool holder, the washer 490 encloses the spring clip 460 and holds the spring clip 460 in the contracted configuration in the same manner as described herein in connection with the aspect of Fig. 2-6 is described.

[0043] Fig. 15 illustrates another aspect of the cutting bit assembly 400 according to the present disclosure, which is substantially similar to the aspect of Fig. 11-14. Corresponding components of the cutting bit assembly 400 of Fig. 11-14 have the same reference numbers. Fig. Figure 15 illustrates a cross-sectional view of the cutting bit assembly 400 at the same location as the view of Fig. 13. The aspect of Fig. 15 differs from that of Fig. 11-14 in that the rotation limiting surface 430 includes a convex surface 442 recessed into the body 422 of the shaft 420. The convex surface 442 may not be coaxial with the rest of the body 422 of the shaft 420, and the convex surface 442 may have a different radius (i.e., larger or smaller) than the rest of the body 422 of the shaft 420. The projection 470 includes a concave surface 479 configured to press the pin 450 against the convex surface 442. The concave surface 479 of the projection 470 may not be coaxial with the rest of the spring clip 460, and the concave surface 479 may have a different radius (i.e., larger or smaller) than the rest of the spring clip 460. The concave surface 479 of the projection 470 is configured to bear against the pin 450 to limit or prevent rotation of the body 422 of the shaft 420 relative to the spring clip 460.

[0044] Fig. 16 illustrates another aspect of the cutting bit assembly 400 according to the present disclosure, which is substantially similar to the aspect of Fig. 11-14. Corresponding components of the cutting bit assembly 400 of Fig. 11-14 have the same reference numbers. Fig. Figure 16 illustrates a cross-sectional view of the cutting bit assembly 400 at the same location as the view of Fig. 13. The aspect of Fig. 16 differs from that of Fig. 11-14 in that the pin 450 is not a separate component, but the rotation limiting surface 430 of the aspect of Fig. 16 includes an integrally formed projection 452. The projection 452 may extend longitudinally parallel to the flat surface 440. The projection 452 may have the shape of a half-cylinder, ie, a longitudinally split cylinder, and may generally cooperate with the projection 470 of the spring clip 460 in a similar manner to the pin 450 of Fig. 11-14. In particular, the projection 470 of the spring clip 460 is configured to bear against the projection 452 to limit or prevent rotation of the body 422 of the shaft 420 relative to the spring clip 460.

[0045] The Fig. 19-24 illustrate an aspect of the cutting bit assembly 500 according to the present disclosure that corresponds to each of the previously described aspects of the Fig. 1-16. Components of the cutting bit assembly 500, the components of the aspect of Fig. 2-6 are represented by the number 300 added to the reference number of the corresponding component. (For example, the cutting tip 510 corresponds to Fig. 19-24 of the cutting tip 210 of the Fig. 2-6). Components that are not specifically designed with regard to Fig. 19-24, it can be assumed that they are essentially similar to the corresponding components of the aspect of Fig. 2-6. Similarly, components that are in Fig. 1-16, but not further described, are assumed to be substantially similar to the corresponding components of the aspect of Fig. 19-24 are.

[0046] Fig. 19 shows the cutting bit assembly 500 in an installed configuration with the washer 590 abutting the flange 514 of the cutting tip 510. The installed configuration of the washer 590 corresponds to the position of the washer 590 when the cutting bit assembly 500 is inserted into the mounting bore 122 of the tool holder 110 of Fig. 1. In particular, the washer 590 is inserted between the end face 120 of the tool holder 110 (see Fig. 1) and the flange 514 of the cutting tip 510. Fig. 20 shows the cutting bit assembly 500 in an uninstalled configuration with the washer 590 surrounding the spring clip 560 and holding the spring clip 560 in the contracted configuration. The uninstalled configuration of the washer 590 corresponds to the position of the washer 590 before installation into the tool holder 110 or after removal from the tool holder 110. For example, the uninstalled configuration may correspond to the position of the washer 590 on a new cutting bit assembly 500 delivered to a customer and / or the position of the washer 590 after the cutting bit assembly 500 has been removed from the tool holder 110 for reuse.

[0047] As in Fig. 19 and Fig. 20, a fillet 516 may be formed between the flange 514 and the shoulder 528 of the shank 520 of the cutting bit assembly 500. The fillet 516 may have a radius of, for example, 1.5 mm. In some aspects, the fillet 516 may be replaced or supplemented by a chamfer. The bore 591 of the washer 590 may have a beveled distal edge 593 that fits over the fillet (or chamfer) 516 to allow the washer 590 to sit flush against the flange 514, as shown in Fig. 19. Further details of the beveled distal edge 593 of the bore 591 are described herein with reference to Fig. 22-24 described.

[0048] With further reference to Fig. 19 and Fig. 20, a proximal edge 518 of the flange 514 may be chamfered. An angle 517 (see Fig. 20) The bevel of the proximal edge 518 may range from about 40° to about 80°, and in some aspects, about 60°, relative to a longitudinal axis 502 of the cutting bit assembly 500. In some aspects, the proximal edge 518 may have a radius instead of, or in addition to, the bevel.

[0049] Further referring to Fig. 19 and Fig. 20, the distal edge 566 of the spring clip 560 may be beveled to guide the spring clip 560 into the bore 591 of the washer 590, e.g., when the cutting bit assembly 500 is removed from the mounting bore 122 of the tool holder 110 (see Fig. 1). In particular, the distal edge 566 of the spring clip 560 engages the bore 591 of the washer 590 when the washer 590 is removed from the shoulder 528 of the shank 520 and onto the spring clip 560 during the transition of the cutting bit assembly 500 from the installed configuration of Fig. 19 for the non-installed configuration of Fig. 20. An angle of the bevel of the distal edge 566 may be in a range of about 30° and about 60°, and in some aspects about 45°, relative to the longitudinal axis 562 of the spring clip 560. In some aspects, the distal edge 566 may have a radius instead of, or in addition to, the bevel.

[0050] Referring to Fig. 21 is a detailed view showing the proximal end 524 of the shaft 520 and a proximal edge 565 of the spring clip 560. When the spring clip 560 is in the contracted configuration (i.e., when the washer 590 surrounds the spring clip, as shown in Fig. 20), the outer diameter of the spring clip 560 is larger than the outer diameter of the proximal end 524 of the shaft 520. This allows the proximal end 524 of the shaft 520 to slide into the mounting hole 122 of the tool holder 110 (see Fig. 1) while the spring clip 560 has a slight interference fit with the mounting bore 122. To provide a smooth transition between the proximal end 524 of the shaft 520 and the spring clip 560 and to guide the spring clip 560 into the mounting bore 122, the distal edge 566 of the spring clip 560 may be chamfered. The chamfer of the distal edge 566 of the spring clip 560 may have an angle 567 in a range of about 30° and about 60°, and in some aspects about 45°, relative to the vertical outer surface of the spring clip 560. In some aspects, the distal edge 565 of the spring clip 560 may have a radius instead of, or in addition to, the chamfer.

[0051] With reference to Fig. 22-24, the washer 590 is a generally annular structure defining a bore 591 extending along an elongated washer axis 581 through the center of the annular structure. A diameter 595 of the bore 591 is sized to hold the spring clip 560 in the contracted configuration when the washer 590 is disposed around the spring clip 560, as shown in Fig. 20. Thus, the outer diameter of the spring clip 560 in the contracted configuration is the same as the diameter 595 of the bore 591. In some aspects, the diameter 595 of the bore 591 is in a range of about 18 mm to about 22 mm, and in some aspects, about 20 mm. The washer 590 has an outer diameter 594 in a range of about 40 mm to about 50 mm, and in some aspects, about 44.5 mm. In some aspects, the outer diameter 594 is approximately equal to the outer diameter of the flange 514 of the cutting tip 510 (see Fig. 19 and Fig. 20).

[0052] With continued reference to the Fig. 22-24, the proximal edge 592 of the bore 591 may be chamfered to assist in guiding the washer 590 over the spring clip 560, e.g., when the cutting bit assembly 500 is removed from the tool holder 110 (see Fig. 1). An angle 582 of the bevel of the proximal edge 592 may range from about 15° to about 45°, and in some aspects, about 30°, with respect to the elongated washer axis 581. As mentioned above, the distal edge 593 of the bore 591 may be beveled to fit over the fillet (or bevel) 516 of the flange 514 and the shaft 520 (see Fig. 20) such that the washer 590 rests flush against the flange 514. An angle 583 of the bevel of the distal edge 593 can range from about 30° to about 60°, and in some aspects, about 45°, with respect to the elongated washer axis 581. In some aspects, the angle 583 of the distal edge 593 is greater than the angle 582 of the proximal edge 592 to correspond to the respective functions of the bevels. In particular, the bevel of the proximal edge 592 is configured to engage the spring clip 560, while the bevel of the distal edge 593 is configured to fit over the fillet 516. In some aspects, each of the proximal edge 592 and / or the distal edge 593 of the bore 591 may have a radius instead of or in addition to the bevel.

[0053] As in Fig. As shown in Figure 23, the outer distal edge 598 of the washer 590 may be chamfered at an angle 598 in a range of about 40° to about 80°, and in some aspects about 60°, relative to a vertical axis (i.e., an axis parallel to the washer axis 581). The chamfer of the outer distal edge 598 may have a height 599 in a range of about 1 mm to about 2 mm, and in some aspects about 1.3 mm. In some aspects, the outer distal edge 598 may have a radius instead of, or in addition to, the chamfer.

[0054] As in Fig. 23 and Fig. 24, the washer 590 may have a total thickness 584 in a range of about 3 mm to about 7 mm, and in some cases about 5 mm. As shown in Fig. 24, the thickness 584 of the washer 590 is equal to the sum of the height 585 of the bevel of the proximal edge 592, the height 586 of the bevel of the distal edge 593, and the height 587 of a vertical sidewall 597 between the bevels of the proximal and distal edges 592, 593. The height 585 of the bevel of the proximal edge 592 may range from 1 mm to 2 mm, and in some aspects, about 1.3 mm. The height 586 of the bevel of the distal edge 593 may range from 1 mm to 2 mm, and in some aspects, about 1.5 mm. The height 587 of the vertical sidewall 597 may range from about 1 mm to about 5 mm, and in some aspects, about 2.2 mm. In some aspects, the height 587 of the vertical sidewall 597 is greater than the height 585 of the bevel of the proximal edge 592, and the height 587 of the vertical sidewall 597 is greater than the height 586 of the bevel of the distal edge 593.

[0055] The vertical side wall 597 of the washer 590 engages an outer surface of the spring clip 560 (as in Fig. 20) when the washer 590 is in the uninstalled configuration. The height 587 of the vertical sidewall 597 can be selected to prevent angular misalignment between the washer 590 and the spring clip 560. That is, the height 587 of the vertical sidewall 597 can keep the washer axis 581 substantially parallel to the longitudinal axis 562 of the spring clip 560 (see Fig. 20). In general, as the height 587 increases, the vertical sidewall 597 becomes more resistant to misalignment with the spring clip 560. Therefore, the height 587 of the vertical sidewall 597 is desirably maximized for a given thickness 584 of the washer 590. This can prevent pressing of the washer 590 against the spring clip 560 and / or incomplete seating of the washer 590 on the flange 514 during insertion of the cutting bit assembly 500 into the tool holder 110 (see Fig. 1). However, the height 587 of the vertical side wall 597 is limited by the height 586 of the bevel of the distal edge 593, which must be sufficiently large to provide clearance for the fillet (or bevel) 516 of the flange 514 (see Fig. 19 and Fig. 20). Furthermore, the height 587 of the vertical side wall 597 may be limited by the height 585 of the bevel of the proximal edge 592, which assists in guiding the spring clip 560 in the bore 591, as described herein. Industrial applicability

[0056] The aspects of the cutting bit assembly 200 described in the present disclosure can be used to mill surfaces, such as asphalt roads, when installed in the milling drum 100 of a cold planer (also called a road milling machine or ripper). As the milling drum 100 rotates, the cutting bit assembly 200 breaks the road surface into small pieces that can be removed and taken off-site. The interaction between the rotation-limiting surface 230 of the shank 220 and the projections 270, 280 of the spring clip 260 limits and / or prevents rotation of the cutting bit assembly 200 within the tool holder 110, which can extend the life of the cutting bit assembly 200 and / or the tool holder 110. In particular, by limiting or preventing the rotation of the cutting bit assembly 200, only the cutting side of the cutting tip 210 is subject to significant wear during milling.The non-cutting side of the cutting tip 210 is subject to less or negligible wear and therefore provides structural support to the cutting side of the cutting tip 210. Furthermore, the lack of significant rotation of the cutting bit assembly 200 results in little or negligible wear on the end face 120 of the tool holder 110.

[0057] Referring to Fig. 17 illustrates a flowchart showing an exemplary method 600 for inserting the cutting bit assembly 200 into the tool holder 110. The method 600 includes, in step 602, inserting the shank 220 of the cutting bit assembly 200 into the mounting bore 122 of the tool holder 110 with the spring clip 260 in the contracted configuration. The washer 290 surrounds the spring clip 260, as shown in Fig. 3 to hold the spring clip in the contracted configuration. The proximal end 224 of the shaft 220 is first inserted into the mounting hole 122 and pressed into the mounting hole 122 until the washer 290 contacts the end face 120 of the tool holder 110.

[0058] The method 600 further includes, in step 604, releasing the spring clip 260 from the contracted configuration such that the spring clip 260 exerts a radially outward force against the mounting bore 122 of the tool holder 110, thereby longitudinally and rotationally locking the spring clip 260 within the mounting bore 122. Releasing the spring clip 260 in step 604 may be accomplished by fully pushing and / or hammering the shank 220 into the mounting bore 122 of the tool holder 110 such that the washer 290 is forced onto the shoulder 228 of the shank 220. The shank 220 may be forced into the mounting bore 122, for example, using an air gun equipped with an installation cup to avoid damaging the cutting tip 210.The washer 290 is slid along the outer surface of the spring clip 260 until the washer 290 releases the spring clip 260, moves over the shoulder 228, and contacts the flange 214 of the cutting tip 210. Because the spring clip 260 is no longer radially constrained by the washer 290 in the contracted configuration, the spring clip 260 expands radially and frictionally engages the mounting hole 122 of the tool holder 110. The inner diameter of the mounting hole 122 is smaller than the outer diameter of the spring clip 260 in the expanded configuration, so the spring preload of the spring clip 260 creates a frictional force against the mounting hole 122. In this way, the spring clip 260 is longitudinally and rotationally locked in the mounting hole 122.In addition, the rotation limiting surface 230 of the shaft 220 interacts with the projection 270 of the spring clip 260 to limit the rotation of the shaft 220 and thus the rotation of the cutting tip 210 relative to the spring clip 260 and the mounting bore 122.

[0059] In some cases, attempting to rotate the cutting tip 210 may increase the hold of the spring clip 260 in the mounting hole 122. In the Fig. 2-6, rotation of the shaft 220 relative to the spring clip 260 such that the first flat surface 232 of the shaft 220 engages the third flat surface 272 of the spring clip 260 causes the radially outward force exerted by the spring clip 260 on the mounting hole 122 to increase. This enhances the anti-rotation effect of the spring clip 260. Similarly, rotation of the shaft 220 relative to the spring clip 260 such that the second flat surface 234 of the shaft 220 engages the fourth flat surface 274 of the spring clip 260 causes the force exerted by the spring clip 260 on the mounting hole 122 to increase.

[0060] By limiting or preventing rotation of the cutting bit assembly 200 during operation of the cold milling machine, the life of the cutting bit 200 can be increased by limiting the area of ​​the cutting tip 210 subject to wear. Furthermore, the life of the tool holder 110 can be increased because wear can be reduced by the rotation of the flange 214 and washer 290 against the face 120.

[0061] While the previous descriptions of the method 600 in connection with the Fig. 2-6, it will be apparent to those skilled in the art that the method 600 is equally applicable to the aspects of the cutting bit assembly 300 of Fig. 7-10, the cutting chisel assembly 400 of Fig. 11-16 and / or the cutting bit assembly 500 of Fig. 19-24 could be used. Various features of the cutting bit assembly 500 of Fig. 19-24 may facilitate the performance of the method 600. For example, the bevel (or radius) of the proximal edge 565 of the spring clip 560 aligns the spring clip 560 with the mounting hole 122 of the tool holder 110 ( Fig. 1) to assist in inserting the cutting bit assembly 500 into the mounting bore 122 in step 602. The bevel of the proximal edge 565 thus provides a smooth transition from the proximal end 524 of the shaft 520, which may have a clearance fit in the mounting bore 122, to the spring clip 560, which has a slight interference fit with the mounting bore 122.

[0062] As the washer 590 is slid distally along the spring clip 560 toward the shoulder 528 of the shaft 520, the sidewall 597 of the bore 591 of the washer 590 remains engaged with an outer surface of the spring clip 560 to prevent the washer 590 from tilting relative to the longitudinal axis 562 of the spring clip 560, thereby preventing the washer 590 from being forced against the spring clip 560. As the washer 590 engages the flange 514 of the cutting tip 510, the bevel (or radius) of the distal edge 593 of the bore 591 fits over the fillet 516 to ensure that the washer 590 sits flush against the flange 514.

[0063] Referring to Fig. 18 illustrates a flowchart showing an exemplary method 700 for removing the cutting bit assembly 200 from the tool holder 110. The method 700 includes, at step 702, sliding the shank 220 of the cutting assembly 200 out of the mounting bore 122 of the tool holder 110.

[0064] The method 700 further includes, at step 704, sliding the washer 290 from the shoulder 228 of the shaft 220 over the spring clip 260 while sliding the shaft 220 out of the mounting bore 122 to maintain the spring clip 260 in the contracted configuration. The beveled distal edge 266 of the spring clip 260 and / or the beveled proximal edge 292 of the washer 290 guide the washer 290 onto the spring clip 260. That is, the beveled distal edge 266 of the spring clip 260 forces the spring clip 260 into the contracted configuration when the washer 290 is slid over the distal edge 266 of the spring clip 260. Alternatively or additionally, the beveled proximal edge 292 of the washer 290 forces the spring clip 260 into the contracted configuration when the washer 290 is slid over the distal edge 266 of the spring clip 260.

[0065] Step 704 may be performed at least partially concurrently with step 702. That is, the washer 290 may be slid over the spring clip 260 while the stem 220 is pushed out of the mounting bore 122. In some cases, steps 702 and 704 may be performed with the aid of a push-off tool (not shown) inserted between the washer 290 and the flange 214 of the cutting tip 210. The push-off tool separates the washer 290 from the flange 214 and simultaneously pushes the stem 220 out of the mounting bore 122. The chamfer on the distal edge 298 of the outer diameter of the washer 290 may facilitate the insertion of the push-off tool between the washer 290 and the flange 214.

[0066] In some cases, step 704 is completed when the washer 290 is located approximately midway along the length of the spring clip 260, as in Fig. 3 or Fig. 8. The shank 220 can then be completely removed from the mounting bore 122 without further movement of the washer 290. In particular, the shank 220 can be completely removed from the mounting bore 122 without further movement of the washer 290 by prying or pulling on the flange 214 without exerting any appreciable force on the washer 290. Once the cutting bit assembly 200 has been completely removed from the tool holder 110, the washer 290 holds the spring clip 260 in the contracted configuration so that the cutting bit assembly 200 can be reused (i.e., inserted into a different tool holder).

[0067] While the previous descriptions of the method 700 in connection with the Fig. 2-6, it will be apparent to those skilled in the art that the method 700 is equally applicable to the aspects of the cutting bit assembly 300 of Fig. 7-10, the cutting chisel assembly 400 of Fig. 11-16 and / or the cutting bit assembly 500 of Fig. 19-24 can be used. Various features of the cutting bit assembly 500 of Fig. 19-24 may facilitate the performance of method 700. For example, the chamfer (or radius) of the proximal edge 518 of the flange 514 and / or the chamfer (or radius) of the outer distal edge 598 of the washer 590 may facilitate the insertion of a tool between the flange 514 and the washer 590 during step 702.

[0068] Additionally, features of the washer 590 and / or the spring clip 560 may assist in transitioning the spring clip 560 to the contracted configuration and moving the washer 590 to the uninstalled configuration in step 704. For example, the chamfer of the proximal distal edge 592 of the bore 591 of the washer 590 guides the spring clip 560 into the bore 591 as the washer 590 is slid from the shoulder 528 of the shaft 520 onto the spring clip 560. Specifically, the chamfer of the proximal edge 592 of the washer 590 engages the spring clip 560 and axially aligns the bore 591 of the washer 590 with the spring clip 560 to facilitate smooth sliding of the washer 590 onto the spring clip 560.Alternatively or additionally, the bevel of the distal edge 566 of the spring clip 560 guides the spring clip 560 into the bore 591 of the washer 590 in substantially the same manner. That is, the bevel of the distal edge 566 of the spring clip 560 axially aligns the spring clip 560 with the bore 591 of the washer 590 to facilitate smooth sliding of the washer 590 on the spring clip 560. When the washer 590 engages the spring clip 560, the sidewall 597 of the bore 591 slides along an outer surface of the spring clip 560 to prevent the washer 590 from translating (e.g., tilting) relative to the longitudinal axis 562 of the spring clip 560, thereby preventing the washer 590 from pressing against the spring clip 560.

[0069] Aspects of the cutting bit assembly 200, 300, 400, 500 of the present disclosure facilitate the removal and reuse of the cutting bit assembly. Removal and reuse of the cutting bit assembly 200, 300, 400, 500 may be desirable, for example, when performing a milling operation on a road surface with metal obstacles (e.g., manhole covers) that could damage a PCB cutting tip. The PCB-based cutting bit assemblies 200, 300, 400, 500 of the milling drum 100 may be replaced with non-PCB cutting bit assemblies when used on road surfaces with such metal obstacles. The cutting bit assemblies 200, 300, 400, 500 can then be reinserted into the milling drum 100 to mill a different road surface without metal obstacles.To assist in the removal of the cutting bit assembly 200, 300, 400, 500 from the milling drum 100, the chamfers of the proximal edge 518 of the flange 214 and / or the outer distal edge 598 of the washer 590 enable the insertion of a push-off tool for removing the cutting bit assembly 200, 300, 400, 500 from the tool holder 110, as described above. Furthermore, the chamfers of the proximal edge 592 of the bore 591 of the washer 590 and / or the distal edge 566 of the spring clip 560 assist in the transition of the washer 590 from the installed configuration (. Fig. 19) into the non-installed configuration ( Fig. 20). In addition, the bevel of the proximal edge 565 of the spring clip 560 assists in the alignment of the cutting bit assembly 200, 300, 400, 500 with the tool holder 110 during installation (or reinstallation) of the cutting bit assembly 200, 300, 400, 500.

[0070] It will be apparent to those skilled in the art that various modifications and variations may be made to the disclosed system without departing from the scope of the disclosure. Other embodiments of the system will be apparent to those skilled in the art from consideration of the specification and practice of the system disclosed herein. It is intended that the specification and examples be considered exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 8,646,848

[0005]

Claims

[1] Cutting chisel assembly (500) for attachment to a tool holder (110) of a milling machine, the cutting chisel assembly (500) comprising: a cutting tip (510); a generally cylindrical shaft (520) extending from the cutting tip (510); a spring clip (560) surrounding a body (522) of the shaft (520) and having a contracted configuration and an expanded configuration; and a washer (590) having an installed configuration in which the washer (590) is disposed on a shoulder (528) of the shaft (520) and an uninstalled configuration in which the washer (590) surrounds the spring clip (560) and holds the spring clip (560) in the contracted configuration, wherein at least one distal edge (566) of the spring clip (560) or a proximal edge (592) of a bore (591) of the washer (590) has a bevel or a radius. [2] The cutting bit assembly (500) of claim 1, wherein a proximal edge (518) of a flange (514) of the cutting tip (510) has a bevel or a radius. [3] The cutting bit assembly (500) of claim 1, wherein an outer distal edge (598) of the washer (590) has a bevel or a radius. [4] The cutting bit assembly (500) of claim 1, further comprising a fillet (516) between the shank (520) and a flange (514) of the cutting tip (510), wherein a distal edge (593) of the bore (591) of the washer (590) has a bevel or radius configured to fit over the fillet (516) when the washer (590) is in the installed configuration. [5] The cutting bit assembly (500) of claim 1, wherein the proximal edge (592) of the bore (591) of the washer (590) has a bevel or a radius, a distal edge (593) of the bore (591) of the washer (590) has a bevel or a radius, and the bore (591) has a vertical sidewall (597) between the proximal edge (592) and the distal edge (593). [6] The cutting bit assembly (500) of claim 5, wherein the bevel of the distal edge (593) of the bore (591) has a larger angle (583) than a bevel of the proximal edge (592) of the bore (591) with respect to a longitudinal axis (581) of the washer (590). [7] The cutting bit assembly (500) of claim 5, wherein the vertical sidewall (597) engages an outer surface (102) of the spring clip (560) when the washer (590) is in the uninstalled configuration. [8] The cutting bit assembly (500) of claim 5, wherein a height (587) of the vertical sidewall (597) is greater than a height (585) of the bevel or radius of the proximal edge (592) and greater than a height (586) of the bevel or radius of the distal edge (593). [9] The cutting bit assembly (500) of claim 1, wherein an outer diameter of the spring clip (560) in the contracted configuration is greater than an outer diameter of a proximal end (524) of the shaft (520), wherein a proximal edge (565) of the spring clip (560) has a bevel or radius with a transition between the outer diameter of the spring clip (560) and the outer diameter of the proximal end (524) of the shaft (520). [10] The cutting bit assembly (500) of claim 1, wherein the shank (520) includes a rotation limiting surface (230), and wherein the spring clip (560) includes a projection (270) configured to cooperate with the rotation limiting surface (230) of the shank (520) to limit rotation of the shank (520) relative to the spring clip (560).

Images