Electric mining shovel saddle block assembly with adjustable wear plates

(54) Title: SUPPORT BLOCK SET FOR ELECTRIC MINING EXCAVATOR WITH ADJUSTABLE WEAR PLATES (51) Int.CI .: E02F 3/28; E02F 3/36 (30) Unionist Priority: 9/11/2007 US 11 / 853,784 (73) Holder (s): HARNISCHFEGER TECHNOLOGIES, INC.

(72) Inventor (s): ANDREW M. WURSTER

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Invention Patent Descriptive Report for “SUPPORT BLOCK SET FOR

ELECTRIC MINING EXCAVATOR WITH

ADJUSTABLE WEAR PLATES ”.

BACKGROUND OF THE INVENTION

The present invention relates to mechanical ladders, and, more specifically, to mechanical excavators containing an earth excavation bucket. More specifically, the present invention relates to support block assemblies that support the bucket handle or arm.

Many earth-moving machinery and other types are known. Typical earthmoving equipment or excavators existing up to that time use a bucket or bucket set at the end of a movable arm to excavate materials from horizontal or vertical surfaces. The bucket is usually provided with sharp teeth to dig against the surface being worked. The bucket also includes a cavity to collect the material thus removed. When the earthy material has been received into the bucket, the arm is usually moved to another location to transfer the material. It is customary to unload the material on a dump truck, on a conveyor belt, or simply on another pile of material.

Large electric cable mining excavators use an excavation connection comprising a fixed boom and a combined handle and bucket structure mounted to the boom and which penetrates a pile to lift it and thus fill the bucket. As illustrated in Figure 2, handle 26 comprises two legs 68 that pass through both sides of boom 22. Handle 26 has a rack gear 62 attached to the bottom of each leg 68. A mechanical shift shaft 66 is also mounted horizontally through boom 22. Two pinions 70 with grooves 74 are connected to mechanical shift shaft 66. Rack gear 62 on legs 68 of the handle engages grooves 74 of the pinion gears. An io electric motor and transmission (not shown) rotate the mechanical shift shaft and pinions, thus causing the handle and rack to move forward and retract from the boom. Two sets of support block 78 are mounted on the mechanical shift shaft 66 and are used to keep the handle 26 in the correct position while the excavator is in operation.

During operation, the handle experiences forces in the vertical and horizontal directions. The vertical force is the result of the separation force between the rack gear in the handle and the forward pinion, and the digging loads. The horizontal force is caused by the balance of the machine, the digging loads and the inertia. The purpose of the support block assemblies is to withstand these forces and keep the handle in the correct position.

For better operation, there should be only a small gap between the handle and the support block. This gap is preferably between 0.125 (0.3175 centimeters) and 0.25 inches (0.635 centimeters). If the gap widens above that &lt;) | quantity, the system begins to experience various problems. First, gaps between components contribute to large impact loads as the parts move. Second, a large gap in the top of the loop allows the loop of the loop and the forward pinion to separate from each other. This considerably increases the load on the gear teeth, leading to broken gear teeth, irregular operation and increased noise.

Since the support block assembly provides support for the handle, the handle often moves forward or backward to dig into the pile of material or to rotate the excavator. The relative movement between the components generates wear on the support block surfaces that are in contact with the handle. Support block assemblies are large structures; therefore, it is not conducive to replace the entire support block assembly just because it shows wear on some surfaces. For this reason, replaceable wear plates form a part of the support block assembly. The wear plates are much cheaper and easier to replace than the entire support block assembly. As soon as the wear plates reach a certain thickness, they are discarded, giving space for the installation of new plates. In this way, the integrity of the support block assemblies remains intact.

The wear plates on the support block need to be adjusted regularly to maintain the correct gap between components. Instead of throwing away

Ά wear at each adjustment, they are repositioned to increase service life. Metal shims 164 and 168 are installed between the wear plates and the support block assembly, as shown in Figure 3, to maintain the proper operating gap. This gap adjustment procedure works, but it is time-consuming and complex. The chocks are large, but not very thick, which makes handling difficult. It is also complicated to work between the handle and the support block assembly. The region is covered in lubricant, access is poor and the passages used to access this region are not able to offer ideal access to the wear plates. Since adjusting the wear plates is difficult, it may not be performed or performed less often than necessary.

BRIEF SUMMARY OF THE INVENTION

One of the objectives of the present invention is to offer a support block set with an easier method for adjusting the wear plates by reducing the time needed to make the adjustment.

Other objectives of the present invention are to offer an adjustable support block set that performs the same function as the existing support block sets, but that does not require the use of shims and has the potential to reduce maintenance time to adjust the gaps between the components.

Another objective of the present invention is to offer an adjustable support block assembly that can have a substantial positive impact on the life of the handle rack and the life of the pinion of the mechanical shift shaft.

This invention offers a support block assembly including a main body having an opening for mechanical shift shaft through the lower end of the main body, and an opening for eccentric pin at the upper end of the main body, an eccentric pin received in an opening for eccentric pin at the upper end of the main body, and a wear plate support. The wear plate holder has a pin receiving opening, the eccentric pin being received at the pin receiving opening. Wear plates are mounted on the lower end of the wear plate holder and are adapted to rest on top of a bucket handle.

The present invention also offers a support block assembly including a main body having an upper end and a lower end, the main body having an opening for mechanical shift axis through the lower end of the main body. The support block assembly also includes a tube receiving opening through the main body between the upper end of the main body and the lower end of the main body, and a tube received in the tube receiving opening. There are also means for extending the tube, means for retaining the tube in the tube receiving opening and a wear plate mounted on the end of the tube.

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Other aspects and advantages of the invention will be easily recognized by those skilled in the art when reading the following detailed description, claims and drawings, in which similar numbers are used to designate similar aspects.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a side elevation view of a mechanical excavator incorporating the present invention.

Figure 2 is a cross-sectional view of the first support block and the drive and rack drive pinion mechanism of Figure 1, along line 2-2 in Figure 1.

Figure 3 is a perspective view of the previously existing support block.

Figure 4 is a perspective view of a support block according to the present invention.

Figure 5 is a side view of the support block shown in Figure 4.

Figure 6 is a cross-sectional view of the support block shown in Figure 5, along line 6-6 in

Figure 5.

Figure 7 is a perspective view of the rear of the support block shown in Figure 4.

Before we explain in detail the embodiments of the invention, it should be understood that the invention is not limited, in its application, to the details of the construction and the dispositions of the components presented in the description below or illustrated in the drawings. The invention is susceptible to other embodiments and to be practiced or carried out in different ways. In addition, it should be understood that the phraseology and terminology used in this document are for description purposes and should not be construed as a limitation. The use of the terms "including" and "comprising", and their variations, is intended to encompass the items listed hereinafter and their equivalents, as well as additional items and their equivalents. The use of the term “consisting of”, and its variations, is intended to cover only the items listed after it and its equivalents.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

A mechanical excavator 10 is illustrated in Figure 1. It is to be understood that the present invention is capable of use in other mechanical excavators known in the art and that the mechanical excavator 10 is presented only as an example of such a mechanical excavator. The mechanical excavator 10 comprises a chassis 14 supported for movement on the ground. Specifically, the chassis 14 is a swivel housing mounted on a movable base, such as tracks 18. A fixed boom 22 extends upwards and out of the chassis 14. A bucket handle 26 is mounted on the boom 22 for movement around a support block and a rack and pinion advance drive mechanism 30 for articulated movement in relation to the boom 22 around a generally horizontal axis 32 of the bucket handle 32, and for translational (non-pivotable) movement of the bucket handle 26 in relation to the boom 22. The bucket handle 26 has a front end 34. A bucket 38 is mounted on the front end 34 of the bucket handle 26 in the conventional manner. On the outer end 42 of the boom 22 there is a pulley 56, and a lifting rope or rope 60 extends over the pulley 46 from a winch drum 54 mounted on the chassis 14 and is connected to the bucket 38.

The support block set of this invention is illustrated in Figure 4. The new support block set 82 replaces the support block sets 78 (see Figures 2 and 3) of the prior art. The support block assembly 82 includes a main body 86, two eccentric pins 90, means mounted on the main body 86 to rotate the eccentric pins 90 synchronously, a wear plate or cast member support 94 and upper wear plates 100 mounted on the lower end 104 (see Figure 6) of the casting 94 and adapted to rest on the upper surface 108 (see Figure 2) of the handle of the bucket 26. More particularly, the main body 86 has an upper end 112 and a lower end 114 and a mechanical shift shaft opening 118 through the lower end 114 of the lower body. Two eccentric pin openings 116 are spaced at the upper end 112 of main body 86, and each eccentric pin 90 is received in a different eccentric pin opening 116.

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More particularly, the casting 94 has an upper end 118 and a lower end 120, and two pin receiving openings 122. The casting 94 receives each different eccentric pin 90 in each of the pin receiving openings 122.

The upper wear plates 100 are connected to the casting 94 by screws (not shown). This casting 94 is connected to the support block assembly 82 by the two large eccentric pins 90. The eccentric pin 90 (see Figure 6) is a pin that has two sections 91 and 92 with different diameters that are not concentric. As the gap between the upper surface 108 of the handle 26 and the upper wear plate 100 increases due to wear, the eccentric pins 90 are slightly rotated. Since the pins 90 are eccentric, their rotation will cause a meat action between the pins 90 and the casting 94. This meat action modifies the gap between the upper surface 108 of the handle 26 and the upper wear plate 100. When the correct gap is reached, eccentric pins 90 are locked in place until the next adjustment.

More particularly, the means mounted on the main body 86 for rotation of the eccentric pins 90 in sync comprise each pin 90 having a large sprocket 136 (see Figure 7) mounted on one end of the pin on one side 140 of the main body 86, a small double notch gear 144 (illustrated transparently in Figure

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7) rotatably mounted on the first side 140 of the main body 86, a first endless belt 148 engaged on one of the large sprockets 136 and the small sprocket 144, and a second endless belt 148 engaged on the other of the large sprockets 136 and the small sprocket 144, so that when the small sprocket 144 is rotated and the belts 148 are moved, the large sprockets 136 rotate synchronously.

More particularly, each of the large sprockets 136 is attached to each respective outer face 152 of each eccentric pin 90, as shown in Figure 7. Small sprocket 144 is connected to an adjustment pin 154. When an adjustment is made If necessary, the large sprockets are unlocked (the locking mechanism is not shown) and the adjusting pin 154 is rotated. This rotation causes the belt 148 to rotate both large sprockets, which, in turn, rotate both eccentric pins 90 together. The gap between the handle and the upper wear plate 100 changes due to the cam action of the eccentric pins 90 on the casting 94.

The support block assembly 82 also includes two threaded tube receiving openings 128 spaced in the direction of horizontal movement of the handle. The openings 128 extend through the main body 86 between the upper end 112 of the main body and the lower end 114 of the main body. Assembly 82 also includes two threaded tubes 124, each of which is received in one of the tube receiving openings 128, means for rotating tubes 124 and means for locking tubes 124 in tube receiving openings 128. The set of support block 82 also includes two lower wear plates 132, each of which is mounted on the end of one of the tubes 124.

More particularly, when the bottom wear plate loses thickness due to wear, a locking key 156 is removed and the threaded tube 124 is rotated until the correct operating gap is obtained. After the breach is obtained, the locking key 156 is installed again.

This support block set 82 differs from the previous support block set 78 in several aspects. The existing support block sets 78 used wear plates that were fitted with shims. The meat-adjusting support block 82 uses eccentric pins 90 for the upper wear plate 100 and threaded tubes 124 for the lower wear plate 132 to adjust the gap. Shims are not used to make the adjustment. The uppermost wear plates in the existing support block sets 78 must be adjusted separately. The cam block assembly 82 with cam adjustment adjusts the two upper wear plates 100 at the same time. This is due to the fact that the adjusting belt and sprocket assembly is connected to both eccentric pins 90.

The adjustable support block assembly of the present invention has the potential to reduce downtime

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maintenance required to adjust the wear plates. This is due to several reasons. First, there are no shims to be added or removed. Second, both upper wear plates are connected to a casting and adjusted at the same time. Third, all adjustments are made from the outside of the support block assemblies, which provides unimpeded access to all mechanical equipment.

Various aspects of the invention are presented in the following claims.