Universal Pick Adapter

Abstract

An adapter may allow for non-rotating degradation tips to be secured to holders traditionally used for accepting rotatable bits. Such an adapter may comprise a body comprising an interface on one surface and a seat on an opposing surface. The interface may comprise a form complementary to an end of a holder and the seat may comprise a form for accepting a hardened tip.

Description

BACKGROUND OF THE INVENTION

Degradation picks are known to be used in such fields as road milling, mining and trenching to engage and degrade tough materials such as asphalt, concrete and rock. Such degradation picks may be secured to an exterior of a rotating drum or continuous chain so as to be repeatedly brought into contact with a surface of a material to be degraded. Each degradation pick may comprise a hardened tip designed for repeated impact with a tough material. Such repeated impact may break up the tough material into aggregate pieces that may be removed. To secure such degradation picks to a rotating drum or continuous chain, a generally cylindrical shank opposite the hardened tip may be disposed within a bore within a block that is rigidly fixed to the drum or chain.

Certain types of degradation picks may perform better when allowed to rotate around an axis. For instance, allowing degradation picks comprising tungsten carbide tips to rotate while in use may distribute wear more evenly around a circumference of such degradation picks which may prolong their useful life. In such cases, rather than disposing the shank directly into a bore of a block, where rotation could undesirably wear the block, the shank may be disposed within a bore of a non-rotating holder that itself is disposed within a block. Thus, the holder may receive any wear from rotation of a degradation pick while generally protecting the block.

For example, U.S. Pat. No. 7,229,136 to Sollami describes rotatable tools mounted in non-rotatable retainers in machines used to cut hard surfaces. The useful life of the tools is enhanced by the rotation of the tool, causing it to wear evenly around its circumference. The tools have a tapered forward cutting end and a cylindrical shank that rotatably fits within a complementarily shaped bore in a tool holder.

Other types of degradation picks, however, may perform better when not rotating. For instance, degradation picks comprising polycrystalline diamond tips may benefit from non-rotation as the significant wear resistance of such tips may shield a portion of the degradation pick's body that in turn may support the tip and thus extend life.

For example, U.S. Pat. No. 8,668,275 to Hall, et al. describes a pick comprising a shank that is configured to be rotationally fixed within a block of a driving mechanism and a tip configured to degrade a formation. A support side, or spinal region, may be configured to support the tip while the tip shields the support side, or spinal region, from the formation.

The blocks that secure degradation picks to rotating drums or continuous chains are often rigidly fixed by means of a weld. As such, the time and energy required to replace or exchange such blocks may be significant in comparison to that of replacing or exchanging a degradation pick. Thus, it may be desirable to form both rotating and non-rotating degradation picks that may be secured within a single type of block.

BRIEF SUMMARY OF THE INVENTION

An adapter may allow for non-rotating degradation pick tips to be secured to holders traditionally used for accepting rotatable bits. Such an adapter may comprise a body comprising an interface on one surface and a seat on an opposing surface. The interface may comprise a form complementary to an end of a holder and the seat may comprise a form for accepting a hardened tip.

The interface may be secured to a holder at an end of the holder exposed when the holder is positioned within a block that may be secured to a rotatable drum or continuous chain. The interface may be rigidly secured to such a holder by means of a weld, braze, epoxy, shrink fit, or press fit in a nonrotatably manner.

The seat may be rigidly secured to a hardened tip by means of a weld, braze, epoxy, shrink fit, or press fit. Such a hardened tip may comprise a superhard material attached to a substrate and a bolster attached to the substrate opposite the superhard material. The superhard material may comprise polycrystalline diamond attached to a carbide substrate via sintering.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an orthogonal view of an embodiment of a road milling machine.

FIG. 2 is an orthogonal view of an embodiment of a mining machine with a magnified view of a degradation pick secured within a block.

FIG. 3 is an orthogonal cutaway view of an embodiment of a rotatable drum supported by a road milling machine comprising a plurality of degradation picks secured thereon.

FIGS. 4 and 5 are a perspective view and a longitudinal sectional view, respectively, of embodiments of degradation picks.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an embodiment of a road milling machine 100 of the type commonly used to engage and degrade asphalt or concrete to construct or resurface roads and other large surfaces. The road milling machine 100 may be supported and transported by continuous tracks 150, wheels or other means known in the art. A rotatable drum 110 may be secured to an underside of the road milling machine 100 with a plurality of degradation picks attached to an exterior thereof. As the rotatable drum 110 is rotated, the degradation picks may repeatedly engage a surface upon which the road milling machine 100 is traveling.

FIG. 2 shows an embodiment of a mining machine 200 of the type commonly used to engage and degrade rock and other subterranean formations to extract valuable materials from the earth. The mining machine 200 may comprise a continuous chain 210 with a plurality of degradation picks 220 (shown in magnified view) secured thereto. Each of the degradation picks 220 may comprise a hardened tip 228 designed for repeated engagement with a tough material. Such repeated engagement may break up the tough material into aggregate pieces that may be removed. Each of the degradation picks 220 may also comprise a generally cylindrical shank opposite the hardened tip 228 that may be disposed within a bore within a block 260 that is rigidly fixed to the continuous chain 210.

FIG. 3 shows an embodiment of a rotatable drum 310 secured to an underside of a road milling machine 300. The road milling machine 300 may rotate the rotatable drum 310 around an axis generally parallel to a surface 355 upon which the road milling machine 300 may travel. The rotatable drum 310 may comprise a plurality of degradation picks 320 secured around an exterior thereof. As the rotatable drum 310 rotates, the degradation picks 320 may repeatedly impact the surface 355 which may comprise tough material of any variety such as asphalt or concrete. The repeated impact of degradation picks 320 against the surface 355 may allow the plurality of degradation picks 320 to degrade the surface 355 and break it into aggregate pieces.

FIGS. 4 and 5 show embodiments of degradation picks 420, 520 each comprising a holder 422, 522, an adapter 424, 524, and a hardened tip 426, 526. The holder 422, 522 may be a typical holder of the type known in the art. Such holders are generally capable of receiving a rotatable bit within an opening therein. The holder may secure the rotatable bit to a block (not shown) while generally protecting the block from rotational wear of the bit. As seen in FIG. 5, the adapter 424, 524 may comprise an interface 523 complementary to an end of the holder 422, 522 exposed when the holder 422, 522 is disposed within a block. The adapter 424, 524 may be rigidly attached to the holder 422, 522 by means of a weld, braze, epoxy, shrink fit, press fit, or other means of rigid attachment known in the art. As also seen in FIG. 5, the adapter 424, 524 may further comprise a seat 525 opposite the interface 523 for accepting the hardened tip 426, 526. The hardened tip 426, 526 may comprise a polycrystalline diamond, or other superhard material 527, sintered to a tungsten carbide substrate 528 and a bolster 529 attached to the substrate 528 opposite the superhard material 527. The hardened tip 426, 526 may be rigidly attached to the adapter 424, 524 by means of a weld, braze, epoxy, shrink fit, press fit, or other means of rigid attachment known in the art.

Through use of such an adapter, a non-rotatable degradation tip may be secured to a block designed to receive a holder intended for the receipt of rotatable type degradation bits. This may allow for rapid interchange between rotatable and non-rotatable type operations without requiring the time consuming and exhaustive replacement of welded blocks.

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. An adapter for mating a hardened tip to a holder, comprising: a body comprising an interface on one surface and a seat on an opposing surface;the interface comprising a form complementary to an end of a holder; andthe seat comprising a form for accepting a hardened tip.

2. The adapter of claim 1, wherein the interface is secured to a holder.

3. The adapter of claim 2, wherein the interface is secured to the holder at an end of the holder exposed when the holder is positioned within a block.

4. The adapter of claim 3, wherein the block is secured to a rotatable drum or continuous chain.

5. The adapter of claim 2, wherein the interface is rigidly secured to the holder by means of a weld, braze, epoxy, shrink fit, or press fit.

6. The adapter of claim 2, wherein the interface is nonrotatably secured to the holder.

7. The adapter of claim 1, wherein the seat is secured to a hardened tip.

8. The adapter of claim 7, wherein the seat is rigidly secured to the hardened tip by means of a weld, braze, epoxy, shrink fit, or press fit.

9. The adapter of claim 7, wherein the hardened tip comprises a superhard material attached to a substrate.

10. The adapter of claim 9, wherein the hardened tip further comprises a bolster attached to the substrate opposite the superhard material.

11. The adapter of claim 9, wherein the superhard material is attached to the substrate via sintering.

12. The adapter of claim 9, wherein the superhard material comprises polycrystalline diamond.

13. The adapter of claim 9, wherein the substrate is formed of carbide.