DEVICE FOR EXTRACTING CUTTING BIT FROM HOLDER

Abstract

A device for extracting a cutting bit from within a securement hole in cutting equipment. The device has a base body having an open base end that contact the cutting equipment that surrounds the cutting bit. An elongated drive body having a threaded member with a threaded bore, rotatively contacts the base body, and a threaded post having a threaded portion is threaded within the threaded bore of the elongated drive body, and has a lower end extending into the base body. A pair of bit jaws are attached to the lower end of the threaded post, each having an in-turned ledge for engaging a peripheral groove of the cutting bit. By rotating the drive body, the threaded post is drawn axially upwardly, and with it the pair of bit jaws, to withdraw the cutting bit from the hole in the cutting equipment.

Claims

1. A device for extracting a cutting bit from within a hole in a cutting bit holder or in cutting equipment, comprising: a. a base body having an open base end and a top end comprising a contact surface having an aperture, the base end in contact with a surface of the cutting bit holder or the cutting equipment that surrounds the cutting bit; b. an elongated drive body have a center axis and a threaded member having a threaded bore along the center axis, and having a bottom end comprising a contact surface having an aperture, the contact surface in rotative contact with the contact surface of the base body, and a top drive end; c. a threaded post including a threaded portion threaded within the threaded bore of the elongated drive body, and a lower end extending through the apertures in the bottom end of the drive body and in the top end of the base body; d. a pair of bit jaws attached to and extending below opposite sides of the lower end of the threaded post, each bit jaw having an in-turned ledge at the lower end for engaging a cutting bit, the pair of bit jaws with the engaged cutting bit being disposed within a space at the base end of the base body; where rotating the drive body draws axially and upwardly the threaded post and the pair of bit jaws engaged with the cutting bit, to withdraw the cutting bit from the hole in the cutting bit holder.

2. The device according to claim 1 where a length of the threaded bore of the drive body is at least the diameter of the threaded portion of the threaded rod.

3. The device according to claim 2 where the length of the threaded bore is at least 25% longer than the diameter of the threaded rod.

4. The device according to claim 3 where the length of the threaded bore is at least 50% longer than the diameter of the threaded rod.

5. The device according to claim 4 where the length of the threaded bore is at least 100% longer than the diameter of the threaded rod.

6. The device according to claim 5 where the length of the threaded bore is at least 150% longer than the diameter of the threaded rod.

7. The device according to claim 1 where the threaded bore includes at least 10 threads.

8. The device according to claim 7 where the threaded bore includes at least 15 threads.

9. The device according to claim 1 where the contact surface of the base body and the contact surface of the drive body are confronting annular surfaces.

10. The device according to claim 1 where the contact surfaces are polished surfaces.

11. The device according to claim 1 where the top drive end includes a square through hole configured for a square socket driver.

12. The device according to claim 1 where the base body is cylindrical, and the drive body is a square cylinder.

13. The device according to claim 1 where the cutting bit holder is the cutting equipment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 shows a tool of the present invention for separating a cutting bit from a cutting bit auger with a base body, a drive body and a threaded post.

[0026] FIG. 2 is an exploded view of the tool, showing the base body, the drive body and the threaded post, and further illustrating a pair of bit jaws and a pin to fix the bait jaws to the bottom end of the threaded post.

[0027] FIG. 3 shows a sectional view of the lower end of the base body of the tool with the bit jaws positioned in an expanded position for surrounding a cutting bit anchored into a securement bole in the auger.

[0028] FIG. 4 shows a sectional view of the lower end of the base body of the tool with the bit jaws positioned in engagement with the cutting bit.

[0029] FIG. 5 is a sectional view of the tool with the base body braced against the auger, and confining the bit jaws in their engagement with the cutting bit.

[0030] FIG. 6 is a sectional view of the tool after rotating the drive body to draw up the threaded post and the bit jaws, to extract cutting bit from the securement hole.

DETAILED DESCRIPTION OF THE INVENTION

[0031] A tool 10 for separating a cutting bit 90 from an auger 94 is shown in FIGS. 1-3. An auger 94 including cutting bits 90 is shown in FIG. 7. The cutting bit 90 (FIG. 3) has a base end 93 that is inserted into a retaining hole 96 of a cutting bit holder or cutting equipment, illustrated as an auger 94, and an upper end protruding above a surface 95 of a portion of the auger 94. Cutting bits 90 and the auger 94 are known in the prior art. These cutting bits 90 are typically provided with engagement surfaces, such as an annular peripheral groove 92, that provides control surfaces on the cutting bit 90 to facilitate attachment of a gripping element, illustrated as bit jaws 50, for removal of the cutting bit 90 from the auger 94. The bit jaws 50 include an in-turned ledge 54 for engaging and securing into the annular peripheral groove 92 from opposite sides of the cutting bit 90. The in-turned ledge has an arcuate that follows the outer curvature of the wail of the bit jaw 50. The in-turned ledges 54 provide simple lever-type devices used on the surface of the grooves 92 to provide some mechanical advantage in generating the upwardly-directed force required to remove the cutting bit 90 from the hole 96.

[0032] The tool 10 includes a base body 20 that provides an outer frame and serves as a brace for placement of the tool against a surface of the cutting equipment or holder. The base body 20 has opposed ends. A first end 22 engages the outer surface of the auger 94, and a top end 24. The ends 22 and 24 are separated longitudinally by a cavity or inner space circumscribed by cylindrical wall 21 of the base body 20. The diameter of cylindrical base body 20 is sufficient to capture or surround the cutting bit 90 with the two opposed bit jaws 50 affixed thereto (shown in FIG. 5), and yet is limited in diameter sufficiently to restrain the bit jaws 50 in secured engagement with the cutting bit 90. The cavity or inner space is of sufficient axial dimension to retain the captured cutting bit between a secured position of the cutting bit 90 within the hole 96 (shown in FIG. 5) and an extracted position with the cutting bit 90 drawn at least partially out of the hole (shown in FIG. 6).

[0033] The tool 10 also includes jaws 50, including a pair of bit jaws 50a,50b. The bit jaws 50 have an arcuate wail with an inner surface that, when engaged with the cutting bit, conforms to the outer cylindrical surface of the cutting bit 90. The lower end 53 has an in-turned ledge 54 that extends either continuously or intermittently along the lower end, for engaging and securing into the annular peripheral groove 92 of the cutting bit 90. The lower end 53 of the bit jaws 50 extends downward and below the lower end 45 of the threaded poet 40. In the illustrated embodiment, there is a pair of jaws 50a,50b disposed on opposite sides of the cutting bit. Each jaw 50 extends up to half the circumference of the outer surface of the cutting bit. Alternatively, additional jaws can be provided, spaced in between the initial pair of jaws 50. The top end 51 of the bit jaws 50 (50a,50b) has an aperture 52. A cylindrical pin 60 extends horizontally through a bore 44 formed in the lower end 45 of a threaded post 40. The extending opposite ends 61, 62 of the pin 00 engage the apertures 52 in the top ends 51 of the jaws 59 for exerting upward, extracting force on the bit jaws 50, and with them, the cutting bit 90. The ends 61,62 of the pin 60 through die apertures 52 also provides a means for pivoting the lower end 53 of the bit jaws 50 laterally outward and away from the axial centerline 100 as shown in FIG. 3, to disengage and re-engage the jaws 50 with the cutting bit 90, as shown in FIG. 4.

[0034] The threaded post 49 includes a threaded portion 41 that extends from proximate its lower end 45, to its upper end 43. The threaded portion 41 extends through the aperture 28 at the top end 24 of the base body 20, and upward through an aperture 38 in a bottom end 34 of, and into, a drive body 30 as shown in FIG. 5. The drive body 30 includes a threaded member 32, near its bottom end 34. The threaded member 32 has a threaded bore 39 extending axially along line 100 therethrough, with the threaded portion 41 disposed therein.

[0035] The threaded post 40 provides a screw means for the drive body 30 to be rotated relative to the base body 20. The rotation of the drive body 30 relative to the base body 20 draws axially and upwardly the threaded post 40 within the base body 20 and through the drive body 30. Operation of the device intends that the threaded post 40 is drawn upward, but does not rotate relative to the base body 20. The helical threads of the rotating threaded bore 39 draw the threaded post 40 upward through the threaded member 32. The torque required to rotate the drive body 30 can be applied at a top drive end 36. The top drive end 36 can be driven in rotation by a lever having a drive end (not shown), and can include a square through hole that is configured for a square socket driver.

[0036] Due to the very high force required to extract the cutting bit 90, the axial forces and pressures exerted by the threads 42 of the threaded portion 41 upon the threads of the threaded bore 39 are likewise very high. The increased of the length of the threaded bore 39, relative to conventional nuts, reduces proportionally the force and pressure exerted per helical thread. The longer length of the threaded bore 39 allows the application of higher torque, and greater extracting force, upon the cutting bit, without damaging or destroying the threads of the threaded post 40 or the threaded bore 39 of the dive both 30.

[0037] In the illustrated embodiment, the length of the threaded bore 39 of the drive body 30 is about 100% of, or twice, the diameter of the threaded portion 41 of the threaded rod 40. As illustrated, the number of threads in the threaded bore 30 is 18. More or fewer threads can be provided. The thread pitch (helical angle), thread count per length, and coarseness of the threads can be selected to suit the specific need.

[0038] During operation of the tool, and the rotating by torque of the drive body 30 relative to the base body 20, significant friction is generated at the interface of bottom end 34 of the drive body 30 rotating against the top end 24 of the base body 20. To reduce rotational friction between the bodies, the top end 24 of the base body 20 has an annular contact surface 25 of the planar area that outlines the aperture 28, and the bottom end 34 of the drive body 30 has a confronting and mating annular contact surface 35 of the planar area that outlines the aperture 38. The confronting contact surfaces 25 and 35 are smooth, and preferably polished, to reduce rotational friction, and wearing of the elements. During operation, a lubricant or slipping agent, such as greases, can be applied between the confronting surfaces to reduce friction.

[0039] Although the invention has been described in detail with reference to the illustrated preferred embodiment, variations and modifications exist within the scope and spirit of the invention as described and is claimed in the following claims.