1. Field of the Invention
This invention relates to an overlapping pedestal secured to a rotating drum, such as a rotating drum of an asphalt cutter and/or a longwall shearer, having a plurality of the overlapping pedestals mounted on the outer drum surface and, more particularly, to pedestals having a first end to overlap with a second end of an adjacent pedestal.
2. Discussion of the Technical Problem
Mining and construction machines having rotating drums are used in underground mining, such as for coal mining, to remove the coal from the mine wall or to remove asphalt from road surfaces. In general, the drum has a cylindrical tubular body having pedestals mounted on the outer surface of the drum to remove the coal or asphalt. In a typical arrangement, a pedestal is welded onto the outer surface of the drum, a block is welded to the pedestal and a tool body with a cutting bit secured therein is secured to the block. The pedestals are oriented relative to one another and to the rotating axis of the drum to have a selected configuration to optimize the removal of the coal from the surface of the mine or the asphalt from the road surface. The orientation of the cutting bits to optimize cutting is well known in the art and no further discussion is deemed necessary.
As is appreciated by those skilled in the art, a machine is taken out of service when its efficiency goes below a predetermined value. The efficiency can decrease for several reasons, one of which is damage to the pedestal, including separation of the pedestal from the drum surfaces. In general, pedestals are secured to the cylindrical drums by welds connecting the base of each pedestal with the outer surface of the cylindrical drum. The pedestals, even though they may be generally adjacent to one another, are not connected to one another. The separation of a pedestal from the drum surface is usually the result of the failure of the weld securing the pedestal to the drum surface. This failure is usually the result of drum vibration and/or shear force acting on the pedestals during operation. Replacing pedestals on the drum surface is a time and labor intensive job. In some instances, the entire drum must be removed from the machine, and the detached pedestals welded onto the drum surface at an off-site location.
As can be appreciated, it would be advantageous to provide a pedestal design that provides improved retention of the pedestals to the drum surface resulting in an improved rotating drum, thereby reducing the down time to replace detached pedestals.
This invention relates to a pedestal assembly including, among other things, a pedestal having a bottom surface, an opposite top surface, a first side and an opposite second side, a first end having a recess with a downwardly facing surface, a second end having an upwardly facing surface, wherein the downwardly facing surface and the upwardly facing surface are substantially the same distance from the bottom surface. When mounted upon a rotary drum, the downwardly facing surface of the recess of the first end of the pedestal overlaps and rests upon the upwardly facing surface of the second end of an adjacent identical pedestal.
Non-limiting embodiments of the invention include, but are not limited to, the upwardly facing surface having one of a projection or cavity which is mateable with the other of the projection or cavity in the downwardly facing surface. Furthermore, the pedestal may include an upright member extending above the upper surface of the pedestal with the cutting surface of the cutting bit extending above the upright member. Furthermore, the surface of the upright member facing away from the block may have a reference position. Additionally, the upper surface of the pedestal may include a step.
The invention further relates to a drum assembly for a rotary cutter having an elongated body with a first end, an opposite second end and an outer surface. The body is rotatable about an axis extending from the first end to the second end. A plurality of pedestals on the drum are each adapted to receive a block. Each pedestal has a bottom surface securely mounted on the outer surface of the elongated body and an opposite top surface. For at least one pair of adjacent pedestals, one of the pedestals has a first end with a downwardly facing surface and the adjacent pedestal has a recess with an upwardly facing surface, wherein the downwardly facing surface overlaps with and contacts the upwardly facing surface so that the adjacent pedestals overlap.
Still further, the invention relates to individual pedestals, wherein each pedestal is adapted to be secured to a rotary drum used on a mining or construction machine. Each pedestal is adapted to support a block with a cutting bit therein. Each pedestal is comprised of a body having a bottom surface and an opposite top surface, a first side and an opposite second side, a first end having a recess with a downwardly facing surface and a second end having an upwardly facing surface. The downwardly facing surface and the upwardly facing surface are substantially the same distance from the bottom surface, such that when mounted upon a rotary drum, the downwardly facing surface of the first end of the pedestal overlaps and rests upon the upwardly facing surface of the second end of an adjacent identical pedestal.
As used herein, spatial or directional terms, such as “inner”, “outer”, “left”, “right”, “up”, “down”, “horizontal”, “vertical”, and the like, relate to the invention as it is shown in the drawing figures. However, it is to be understood that the invention can assume various alternative orientations and, accordingly, such terms are not to be considered as limiting.
Before discussing several non-limiting embodiments of the pedestal, it is understood that the invention is not limited in its application to the details of the particular non-limiting embodiments shown and discussed herein since the invention is capable of other embodiments. Further, the terminology used herein to discuss the invention is for the purpose of description and is not of limitation. Still further, in the following discussion, unless indicated to the contrary, like numbers refer to similar elements.
The embodiments of the pedestals of the invention are discussed for use on the outer surface of rotating drums of cutting machines. However, the invention is not limited to any particular type of mining or construction machine.
The invention is not limited to the material used to make the pedestal 22, the block 24, the sleeve 25, the tool body 27 and the cutting bit 26, and the selection of materials for making such components are well known in the art. For example, the pedestal 22, the block 24, the sleeve 25 and the tool body 27 can be made of metal, e.g. steel, and the cutting bit 26 made of a material harder than the material to be removed, such as cemented carbide.
In one embodiment of the invention, the pedestal 22 has a bottom surface 30 (see
The pedestal 22 may have registration holes 36 (
With reference to
Additionally, as illustrated in
With reference to
In another embodiment of the invention, a step 55 (
The pedestal 22 may be shaped to promote deflection of material made loose by the cutting bit 26. With reference to
Such a position of the pedestals 22 is generally illustrated in
The sleeve 25 of the pedestal assembly 20 (see
The invention is not limited to the arrangement of the pedestal assembly on the outer surface 32 of the drum 34 (see
Based on the description of the embodiments of the invention, it can be appreciated that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications that are within the spirit and scope of the invention, as defined by the appended claims.