Patent Application
20110180771
The invention relates generally to an apparatus for reducing the impact felt on a machine by cables moving undesirably, such as in a whipping or slapping motion, and for reducing the wear and tear on the cables and, more particularly, to an apparatus for reducing the impact felt by slapping hoisting ropes on an electric mining shovel and for reducing the wear and tear on the hoisting ropes.
Electric mining shovels are useful for digging up, hoisting, and transporting large volumes of earth or other material. Generally, an electric mining shovel includes a dipper that is operatively connected to a housing and is controlled by an operator. More particularly, the dipper is attached to an arm, known in the industry as “the stick.” The stick is pivotally attached to the boom, which is attached to the housing. Hoisting cables attach to the dipper (also known as “the bucket”) and pass through a pulley at the end of the boom and then back into the housing where the hoisting cables or ropes are wound or unwound around a drum so as to hoist or lower the dipper. Near the drum, typically on both sides of the drum, are gantry legs that extend out of the top of the housing and are used to help anchor the boom.
In the extension between the drum and the end of the boom, the hoisting cables or ropes pass through the housing via a window. Typically, the window is only five or six feet by two feet in dimension. As the hoisting cables or ropes aid in hoisting or lowering the dipper once it has dug up an amount of earth, the dipper will occasionally jolt up or down. This jolt of the dipper in turn whips, slaps, or otherwise undesirably moves the hoisting ropes or cables, as the case may be. In such case, the hoisting ropes or cables slap against the window opening in the housing. Over time, the slapping of the cables on the window opening wears out the cable, which can then snap or break completely under the strain on the cable during operation of the shovel. In such case, the only option is to cease operation of the mining shovel until the machine can be repaired. This costs otherwise-valuable time while the shovel is inoperable, and repair and replacement costs are incurred.
Embodiments of the present impact-reduction assembly provide for a simple assembly that is mountable to an electric mining shovel or other machine and is situated so that hoisting ropes or cables pass therethrough as the hoisting ropes or cables extend from the drum, through the housing window, and out to the end of the boom. More particularly, the present impact-reduction assembly is mounted to either the gantry legs of the shovel, just after the hoisting cable comes off of the drum, or to the housing itself between the gantry legs.
In the event that the hoisting ropes or cables are whipped so that they undesirably move, they come into contact with rollers included in a roller frame subassembly, which is configured to move relative to portions of at least one pair of spring box subassemblies while those portions of the spring box subassemblies remain essentially motionless relative to the machine, e.g., mining shovel, to which they are mounted. Thus, when the hoisting rope or cable moves unexpectedly, rather than slap on the window opening of the housing or on other parts of the mining shovel, the rope or cable will impact only the roller frame subassembly of the impact-reduction box. The roller frame subassembly will move against springs or other compressors that will act against the frame subassembly to re-steady it while the rest of the impact-reduction assembly remains essentially motionless. This reduces the wear and tear on the hoisting rope or cable, reduces the risk of the hoisting rope or cable breaking, extends the life of the hoisting rope or cable, and further reduces the impact on the rest of the mining shovel or other machine from the slapping cables.
a is a perspective, elevation view of a left spring box subassembly of the impact-reduction assembly according to the first embodiment with the front spring box side removed so as to be able to see the inside of the spring box subassembly.
b is a perspective, elevation view of a right spring box subassembly of the impact-reduction assembly according to the first embodiment with the front spring box side removed so as to be able to see the inside of the spring box subassembly.
While the impact-reduction box is susceptible of various modifications and alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined herein.
In the following description and in the figures, like elements are identified with like reference numerals. The use of “or” indicates a non-exclusive alternative without limitation unless otherwise noted. The use of “including” means “including, but not limited to,” unless otherwise noted.
A first preferred embodiment of the impact-reduction box is shown in
The roller frame subassembly 12 includes a roller frame made up of a frame top side 14, a frame bottom side 16, a frame right side 18, and a frame left side 20. As shown in
According to the second and third preferred embodiments, shown in
The roller frame subassembly 12 further includes a number of rollers 24. As shown in the figures, it is preferred that the roller frame subassembly 12 include at least four rollers 24. These are preferably nylon rollers having diameters in the range of three to four inches. According to the preferred embodiments, two of the rollers 24 are affixed to the frame top side 14 and two are affixed to the frame bottom side 16 via pillow block bearings 26. Thus, the rollers 24 are arranged to be essentially parallel to the frame top side 14 and the frame bottom side 16.
In this configuration, the roller frame subassembly 12 defines at least one cable pass-through space 48 between the various rollers 24 so that a hoisting cable or cables can be passed through the roller frame subassembly 12. According to the first, second, and third embodiments shown in the figures, the roller frame subassembly 12 defines two cable pass-through spaces 48. More specifically, according to the first preferred embodiment, the frame top side 14, frame left side 20, frame bottom side 16, and frame middle support 22 define a left cable pass-through space 48, while the frame top side 14, frame right side 20, frame bottom side 16, and frame middle support 22 define a right cable pass-through space 48. According to the second and third preferred embodiments, the frame top side 14, frame left side 20, frame bottom side 16, lower frame middle support 22″, and upper frame middle support 22′ define a left cable pass-through space 48, while the frame top side 14, frame right side 20, frame bottom side 16, lower frame middle support 22″, and upper frame middle support 22′ define a right cable pass-through space 48. Thus, one or more hoisting cables may be passed through the roller frame subassembly 12 on either or both of the sides of the frame middle support 22 (or interconnected lower frame middle support 22″ and upper frame middle support 22′) of the roller frame subassembly 12.
Attached to both the frame right side 18 and the frame left side 20 are one of a number of roller frame support blocks 28. Preferably, a pair of roller frame support blocks 28 are used, one connected to the frame right side 18 and one connected to the frame left side 20. Also, preferably, the roller frame support blocks 28 are welded to the respective frame right side 18 and frame left side 20 at essentially a mid-point in the height of the frame right side 18 and frame left side 20. Attached to each roller frame support block 28 is at least one spring support rod 42. According to the first preferred embodiment, one spring support rod 42 is attached to each roller frame support block 28. According to the second and third preferred embodiments, two spring support rods 42 are attached to each roller frame support block 28. Preferably, each spring support rod 42 is aligned perpendicular to the roller frame support blocks 28 and parallel to the other spring support rods 42. Preferably, the spring support rods 42 are made of roll steel with a diameter of approximately two inches. It is preferred that the spring support rods 42 be welded to their respective roller frame support block 28 so that the roller frame support block 28 intersects the spring support rod 42 at approximately a mid-point on the spring support rod 42. In other embodiments, the roller frame support blocks 28 each define a rod insertion hole into which the spring support rod 42 may be inserted and thereafter welded to the roller frame support block 28. In other embodiments, the roller frame support block 28 is connected to the spring support rod 42, but not welded thereto, so that the spring support rod 42 may move relative to the roller frame support block 28.
Each of the spring box subassemblies 30 include a pair of spring box sides 32, a spring box mounting side 34, a spring box bottom 38, and a spring retainer plate 36. Thus, each spring box subassembly 30 is practically a box that is missing one side. However, the shape of the spring box subassembly 30 may be varied, such as that shown in
In some embodiments, such as the depicted second preferred embodiment, a bearing and seal retainer plate 37 is included and mounted to the spring retainer plate 36, as shown in
According to the depicted embodiments, the spring box mounting side 34 of the spring box subassembly 30 further defines a plurality of side mounting points 44 that are designed to accommodate securing the spring box mounting side 34 to the machine. According to the depicted embodiments, the side mounting points 44 are side mounting holes configured for receiving therein screws or other mounting hardware. It is preferred that the spring box mounting sides 34 be each mounted to one of the two gantry legs of a mining shovel machine. In other embodiments, the spring box mounting sides are mounted to the housing of the machine. In addition, the spring retainer plate 36 defines a plurality of retainer plate mounting points 45 that are likewise designed to accommodate securing the spring retainer plate 36 to the machine or to the spring box mounting side 34 and spring box sides 32. In the second and third preferred embodiments, the bearing and seal retainer plates 37 likewise define retainer plate mounting points 45 that are designed to accommodate securing the bearing and seal retainer plates 37 to the spring retainer plate 36. According to all three of the depicted preferred embodiments, the mounting points 44, 45 are holes approximately one inch in diameter.
The spring retainer plate 36 and spring box bottom 38 also define rod insertion holes that are essentially aligned with one another. According to the first embodiment, into each rod insertion hole is placed a journal bearing 46, and through each journal bearing 46 is inserted one of the spring support rods 42. According to the second and third embodiments, the bearing and seal retainer plates 37 also define rod insertion holes that are essentially aligned with the rod insertion holes of the spring retainer plate 36. As such, the spring support rods 42 are inserted into the rod insertion holes of both the spring retainer plate 36 and the bearing and seal retainer plate or plates 37. In the second and third embodiments, journal bearings 46 and/or seals may be included and secured by the bearing and seal retainer plate or plates 37.
Preferably, each spring support rod 42 is welded to a roller frame support block 28. As such, the impact-reduction assembly 10 is configured so that each spring support rod 42 may move relative to the spring retainer plate 36 and the spring box bottom 38 but may not move relative to the roller frame support block 28 to which it is welded. In other embodiments in which the roller frame support block 28 also defines a rod insertion hole into which a spring support rod 42 is inserted, the roller frame support block 28 may move relative to the spring support rod 42. In configurations of these other embodiments, each spring support rod 42 is preferably fixedly attached to a spring retainer plate 36 or spring box bottom 38 such that the spring support rod 42 may not move relative to the spring retainer plate 36 and/or spring box bottom 38 to which it is fixedly attached while the spring support rod 42 may move relative to the roller frame support block 28.
It is further preferred that the spring retainer plate 36 be removable from the spring box sides 32 and the spring box mounting side 34 so that the inner workings of the spring box subassembly 30 may be accessed for maintenance or other purposes. According to the first, second, and third embodiments, each spring retainer plate 36 may be removed from the spring box subassembly 30 via releasing the spring retainer plate 36 at the retainer plate mounting points 45. In this way, the inner workings of the spring box subassembly 30 are accessible without complete disassembly of either the spring box subassemblies 30 or the impact-reduction assembly 10, itself.
Each spring box subassembly 30 further includes a number of springs 40 or other elastically compressible mechanisms, such as a pneumatic mechanism or hydraulic mechanism. According to the depicted embodiments, the elastically compressible mechanisms comprise pairs of coil springs 40. Each of the coil springs 40 are wound around a spring support rod 42, with the two coil springs 40 of the pair being separated from one another on the spring support rod 42 by the roller frame support block 28.
According to the preferred embodiments shown in
During installation of the first preferred embodiment of the impact-reduction assembly 10 (
The installation of the second and third preferred embodiment of the impact-reduction assembly 10 (
According to the second preferred embodiment, the impact-reduction assembly 10 further includes a lubrication system 50 configured to lubricate the rollers 24 during operation of the impact-reduction assembly 10. As shown, the lubrication system 50 is incorporated throughout the roller frame subassembly 12 so as to provide lubrication to the rollers 24 via the block bearings 26 connecting the rollers 24 to the frame top side 14 or frame bottom side 16, as the case may be. Preferably, each end of each roller 24 and, therefore, each block bearing attaching to the roller 24 ends, are provided with lubrication via the lubrication system 50.
While there is shown and described the present preferred embodiments of the impact-reduction box, it is to be distinctly understood that this invention is not limited thereto but may be variously embodied to practice within the scope of this disclosure. From the foregoing description, it will be apparent that various changes may be made without departing from the spirit and scope of the invention as defined by this disclosure. For example, while it is expected that the present impact-reduction box will be particularly useful for mounting on an electric mining shovel so as to reduce the impact on the machine from a hoisting rope unexpectedly or undesirably whipping and to reduce the wear and tear on the hoisting rope from slapping against the window opening in the housing of the mining shovel, the impact-reduction box is likely also useful for mounting on other machines to which cables, robes, chains, or other cable-like attachments are affixed. As such, the drawings and description of the preferred embodiments are to be regarded as illustrative in nature, and not as restrictive in nature.
This is a national phase entry under 35 U.S.C. §371 of International Patent Application PCT/US2009/044718, filed May 20, 2009, published in English as International Patent Publication WO 2009/143276 A2 on Nov. 26, 2009, which claims the benefit under Article 8 of the Patent Cooperation Treaty to U.S. Provisional Patent Application Ser. No. 61/054,555, filed May 20, 2008, the entire disclosure of each of which is hereby incorporated herein by this reference.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US2009/044718 | 5/20/2009 | WO | 00 | 2/3/2011 |
| Number | Date | Country | |
|---|---|---|---|
| 61054555 | May 2008 | US |
