Adjustable wear block for a door system

Abstract

An adjustable wear block for a gantry system may include a housing and a wear pad disposed on an adjustable base within the wear block housing. In one embodiment, the wear block, wear pad, and adjustable base all have a circular cross-section. The threads on the outer side of the base may mate with the threads on the inner wall of the housing. The position of the base and the attached wear pad may be adjusted relative to the housing as the base rotates within the housing. Holes may be provided through the channel or gantry wall to permit adjustment of the position of the base relative to the housing using an adjustment tool after the wear block is secured to the carriage or gantry. In an alternative embodiment, the hydraulic piston may drive the position of the wear pad relative to the wear block housing.

Description

[0001] Priority claim

[0002] This application claims priority from U.S. patent application serial number 18 / 207,879 filed on June 9, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to mast systems for lift trucks or forks for reach trucks (stackers), and more particularly to methods and mechanisms for absorbing forces in mast systems for lift trucks or reach trucks (stackers) to avoid damage to carriages and mast components. Background Art

[0004] Conventional lift trucks and stackers have a gantry system or other lifting system (i.e., fork carriage) that includes a carriage with lifting forks disposed on the gantry (or fork carriage) that raises and lowers the carriage to pick up and carry loads. The forward and rearward forces on the carriage are absorbed by rollers (or guide bearings) mounted on the carriage or gantry and disposed within the gantry channel. A desired amount of clearance is provided between the rollers and the channel sidewalls so that only one sidewall or the other contacts the rollers in response to forward or rearward forces on the carriage to absorb the forces and keep the rollers positioned within the gantry channel as the carriage is raised and lowered.

[0005] The top and bottom wear blocks are arranged on the carriage between the carriage and the gantry channel to prevent the inner wall of the gantry channel from directly hitting the carriage components (such as rollers). In multi-stage elevators, wear blocks can also be arranged at the top and bottom of additional gantry channels to absorb lateral forces on the gantry rails. The wear pads are generally arranged as far as possible (essentially close to the rollers) to absorb lateral (transverse) forces on the carriage or gantry rails that occur during the lifting of the load or during the travel of the loading and unloading vehicle when the load is carried on the lifting forks. The wear blocks are attached to the carriage or gantry rails by welding, bolts or other mechanical or chemical connections. The wear pads are arranged in the wear blocks and can be fixed by threaded bolts, which are arranged through the center of the wear pads and screwed into receiving holes in the base of the wear blocks.

[0006] A certain gap must be maintained between the gantry channel wall and the wear pad to allow the elevator to operate normally. The wear surface of the wear pad must therefore be maintained at a desired distance (e.g., gap) from the channel wall to absorb lateral forces without interfering with the lifting operation. However, since the wear pad is designed to wear over time, the distance between the wear pad and the channel wall is difficult to maintain at a constant level. If the gap is too large, the carriage and / or gantry rails will be allowed to have excessive play (lateral movement) when raising and lowering, resulting in additional wear on the elevator components and possible metal-to-metal contact or scratching. If the gap is too small, sticking or jamming may occur during lifting and lowering operations, interfering with the normal operation of the elevator.

[0007] Furthermore, the wear pads will eventually wear out completely. If the pads are not replaced in a timely manner, metal-to-metal scraping may occur, which may cause damage to the gangway walls and other elevator components and will require the truck to be brought in for repair. Unfortunately, due to the location of the wear pads between the mast and the mast rails or between the mast and the slide, the repair or replacement of the wear pads is extremely difficult and time consuming. Typically, in order to access the wear pads, the truck must be brought back to the dealer or service center for repair. In order to access the pads and repair or replace the wear pads, it is often necessary to remove the slide and / or mast. Sometimes, special gaps are provided in the mast gangway to allow easier access to the wear pads. Although these gaps allow for easier access, it is still difficult to replace or repair the wear pads through these gaps.

[0008] It is desirable to use up as much wear pad material as possible before replacement. Conventionally, each gantry shipped from the factory is shimmed uniquely for that gantry. Due to the manufacturing process, the straightness of each gantry channel is different. Therefore, at the factory, each gantry is measured to find its narrowest point. This dimension is then used to determine the number of shims required for the factory wear pad. As the wear pad is used, one or more additional metal shims or shimming pads of the desired thickness can be placed in the wear block below the pad to push the pad outward to its original distance and allow a greater amount of wear pad material to be consumed. In order to be able to shim the pad, the original distance from the gantry or carriage surface to the pad surface should be known. However, currently, this number is not provided with the gantry for future repairs. And, in any case, it can still be difficult to measure the shims to get the correct clearance.

[0009] Accordingly, due to the difficulty in accessing the wear pads and measuring the correct shims, pads are often completely replaced before they are completely worn, as opposed to shimming to adjust the pad position, to avoid the difficulty of repeatedly adjusting the pads. Replacing the wear pads rather than shimming ensures that the clearance of the mast is the same in the field as when it left the factory. Although labor is saved, this results in material waste and therefore additional material costs. Therefore, although conventional wear pad systems can absorb shocks and help avoid damage to mast and carriage components, they are difficult to access for repair or replacement and are therefore expensive to maintain. It would be advantageous to have a wear pad system that can be more easily repaired and adjusted. Summary of the invention

[0010] Conventional lift trucks have multiple wear blocks with wear pads arranged along the carriage and / or gantry channels to absorb lateral forces in the gantry system. Ideally, the wear pads are arranged as far apart from each other as possible to maximize the ability to absorb lateral forces. However, as previously mentioned, conventional wear pads can be difficult to access for repair or replacement.

[0011] In accordance with the principles of the present inventive concept, the wear block is designed and mounted to a carriage or gantry channel in such a manner that the height of the wear pad (e.g., the distance it protrudes away from the surface) is easily adjusted to position the wearing (contact) surface of the wear pad at an appropriate distance (gap) from the opposing channel wall to absorb lateral forces and prevent damage to the carriage / gantry components without interfering with the lifting operation.

[0012] More specifically, in one embodiment, an adjustable wear block is provided, the wear block having an easily adjustable wear surface position (or wear pad height). A circular housing with an inner inclined surface (e.g., a thread) is attached to a carriage or gantry rail to be arranged between the carriage or gantry rail and the gantry channel wall when the carriage or gantry rail is mounted to the gantry. The wear block housing can be attached to the carriage or gantry rail by welding, bolts, adhesives, or other mechanical or chemical connections. A threaded base (formed of metal or other rigid material) is arranged in the housing so that its position within the housing can be adjusted by rotating the metal base relative to the housing. The wear pad is attached to the base using one or more fasteners, adhesives, or other connection mechanisms. In one embodiment, three threaded bolts are used to fix the wear pad to the rotatable base. A hexagonal hole or other tool receptacle may be arranged in or through the center of the base to allow a tool to be inserted therein to rotate the base relative to the housing. As the base rotates, the wear pad extends further from the housing or retracts into the housing, depending on the direction of rotation of the base. One or more locking holes may also be provided in the base to receive locking screws or pins which prevent the base from rotating when inserted, or other mechanisms may be provided to lock the position of the base. The locking screw may, for example, be a threaded bolt which is threaded into the locking hole. Matching holes may be arranged through the side wall of the carriage or gantry to which the wear block is attached to receive the locking screws or pins and the adjustment tool. A plug or cover may be used to cover the tool receptacle hole in the carriage or gantry wall before and after adjusting the wear pad height.

[0013] The adjustable wear block can be made to be easily retrofitted to existing lift trucks, such as by replicating the attachment mechanism of a conventional wear block. For example, screw holes can be arranged on the adjustable wear block in locations that match mounting screws on or through the carriage or gantry mounting surface. Additional holes can also be formed through the carriage or gantry mounting wall to provide access to the locking holes and tool receptacles.

[0014] In one embodiment, the gap of the wear pad can be set to the desired distance by first adjusting the wear pad to a height at which the wear surface contacts the gantry channel wall, and then rotating the base back with two full rotations of the adjustment tool (and thus the base). In addition, a label or other marking may be provided around the tool receptacle aperture with a scale indicating the relationship between rotation of the adjustment tool and height adjustment (or linear travel distance) of the wear pad. In one embodiment, the base and housing each have a 6 mm pitch, and each segment on the label may represent 0.5 mm of linear travel of the wear pad.

[0015] Since the adjustable wear pad system described above has a known pitch, setting the correct gap is easy: just turn the baseplate until it hits the channel, and then turn it back the number of turns required to match the factory gap. Markings may be provided by the manufacturer on the gantry listing the correct gap for that particular gantry.

[0016] In another embodiment, the height of the wear pad can be hydraulically adjusted to maintain a desired clearance with the mast channel wall. In one embodiment, the wear pad is disposed on or in communication with a hydraulic piston within the wear block. The cross-section of the wear pad and the hydraulic piston can, for example, be the same size and shape, or the hydraulic piston can also be arranged to push against any other desired shape of substrate or wear pad. In other embodiments, the wear pad itself can be a hydraulic piston.

[0017] A hydraulic fluid valve system may be provided which ensures that the wear pads are arranged with a desired clearance from the mast channel wall. An oil feed may be provided to feed oil into a hydraulic cylinder behind a hydraulic piston driving the wear pads. The oil feed is preferably supplied through a first cylinder having a piston arranged therein which is able to slide forward and backward over the entire length of the first cylinder. The first cylinder may have a fluid volume that is defined such that one stroke of the piston corresponds to a predetermined linear travel distance of the wear pad. The predetermined linear travel distance may, for example, be approximately about 2 mm. A check valve may be arranged across the piston so that oil is supplied to the hydraulic cylinder through the piston after the piston has fully traveled forward in the first cylinder. The check valve may include a preloaded spring that requires a predetermined force (pressure) to open. The predetermined pressure may, for example, be approximately about 1 bar. The check valve prevents oil from returning to the oil feed.

[0018] In operation, oil is supplied from the oil feed to the piston in the first cylinder. The piston is driven forward through the first cylinder until it reaches the end of the first cylinder. As the piston travels forward, the piston drives fluid from the first cylinder into the hydraulic cylinder behind the wear pad. As the fluid enters the hydraulic cylinder, the fluid forces the wear pad outward. Since the first cylinder volume is defined so that the full movement of the piston is equal to the movement of the wear pad by a predetermined distance (e.g., 2 mm), the wear pad will be forced to move a predetermined linear distance due to the movement of the piston, or until the wear pad contacts the mast channel wall. If there is still a gap between the wear pad and the mast after the piston has traveled its full distance, the check valve will open and allow additional oil to be supplied to the hydraulic cylinder through the check valve, causing the wear pad to continue to move until it contacts the mast. After the wear pad contacts the mast, the hydraulic piston cannot move further and the hydraulic cylinder cannot receive more oil. When the cylinder cannot receive more oil, the oil feed is then stopped or shut off. In the case where the oil feed is shut off, when force is applied to the wear pad, the piston in the first cylinder is then free to move back to its original position. When the force from the mast acts on the wear pad, the wear pad pushes fluid from the hydraulic cylinder back into the first cylinder, driving the piston backward toward its original position. Since the first cylinder volume corresponds to the predetermined linear travel distance of the wear pad, the wear pad can be forced backward up to a predetermined distance before the piston reaches its original position and further movement of the wear pad is prevented. In this way, the gap can be set to a predetermined distance by selecting the desired fluid volume for the first cylinder. Other ways of providing a predetermined distance of backward travel are also considered. The key is that there is a set space / volume in the hydraulic system that allows a specific amount of backward travel of the wear pad to adjust the pad to its desired gap.

[0019] In one embodiment, the amount of clearance may be made adjustable. For example, the first cylinder may be provided with an additional volume, and an adjusting screw or other stroke limiter may be provided to set the travel distance of the first piston and thus the corresponding maximum linear travel distance of the wear pad. By adjusting the linear travel distance of the wear pad allowed, the clearance may be adjusted and set as required. In another embodiment, a second piston may be provided, which controls a valve to determine when oil is supplied to the hydraulic cylinder, such as when the mast is centered. The second piston may be arranged in a second cylinder, which has a retraction spring biasing the second piston toward a closed position. The oil supply can be selectively supplied to the first cylinder through the second cylinder only when the second piston opens the valve. When the mast is centered, the second piston may open the valve to allow oil to flow into the first cylinder. In this way, the wear pad position is set when the mast is centered. A dump may be provided from the first end of the first cylinder (opposite to the hydraulic cylinder) to allow oil to be released from the first end of the first cylinder when the first piston moves backward.

[0020] Other embodiments provide an automatically adjusting wear block that automatically adjusts the height of the wear pad to provide a desired clearance with the mast channel wall. In one embodiment, the automatically adjusting wear block may include a wear block housing, a wear pad disposed in the housing, and a hydraulic system for adjusting the height of the wear pad. A button may be disposed on the wear block housing next to the wear pad to force the wear pad outward when pressed. A ramp may be provided along the mast channel to activate the button when the carriage / gantry reaches a certain desired adjustment point along its travel.

[0021] In one embodiment, a hydraulic piston in the master cylinder is connected to a button. A ramp in the gantry channel is configured to contact the button at a desired adjustment point during the travel of the slide / gantry. When the ramp contacts the button, the button is pressed and the connected hydraulic piston forces hydraulic fluid from the master cylinder into the slave cylinder, driving a second hydraulic piston, which forces the wear pad outward. A retaining spring may be provided between the wear block and the wear pad to hold the wear pad in the receptacle of the wear block. A shim plate may be provided in the gantry channel at the adjustment point in the travel of the slide / gantry to ensure that the wear pad extends only to the shim plate. This maintains the appropriate clearance with the gantry channel wall. Alternatively, a first piston and cylinder assembly similar to that previously described may also be used to set the clearance for the wear pad. Check valves may be provided between the fluid reservoir and the master cylinder and between the master cylinder and the slave cylinder to ensure that the hydraulic fluid flows only in one direction.

[0022] In an alternative embodiment, the self-adjusting wear pad may also automatically align with the channel. Two or more slave cylinders may be provided along the wear block to actuate different areas of the wear pad. By providing multiple slave cylinders connected to different areas of the wear pad, each individual area of ​​the wear pad may be actuated the correct amount to contact the shim plate in the channel or channel wall. In this way, different areas of the wear pad may extend from the wear block by different amounts to better match the alignment of the channel wall.

[0023] In still another embodiment, the wear block and the wear pad may have a circular cross-section. The wear pad may be arranged on a piston (e.g., using one or more threaded bolts) that is slidably arranged in a receptacle of the wear block. One or more O-rings may be arranged around the piston to prevent leakage of hydraulic oil or grease. An oil / grease joint may be arranged at the bottom of the wear block to supply oil / grease to the piston to drive the piston and the connected wear pad outward. One or more grease lines or oil supply lines may be used to supply oil / grease to one or more of the wear blocks from a single grease point or multiple grease points. The operator may use a grease gun or other hydraulic fluid supply to force the oil / grease into the grease point and drive the piston outward through the grease line. A shim plate may be used to provide a stop point for the outward movement of the wear pad and ensure appropriate clearance with the channel, or a first piston and cylinder assembly similar to that previously described may be used to set the desired clearance.

[0024] Further aspects and advantages will become apparent from the following detailed description of example embodiments, which proceeds with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other objects, features and advantages of the present inventive concept will become more readily apparent from the following detailed description of preferred embodiments thereof as illustrated in the accompanying drawings, in which:

[0026] Figure 1 is an isometric illustration of the frame and mast system for a conventional reach / lift truck.

[0027] Figure 2 yes Figure 1 Cross-section of the gantry system.

[0028] Figure 3 yes Figure 1 A close-up of area 3.

[0029] Figure 4 Is from Figure 1 Isometric illustration of the carriage of the gantry system.

[0030] Figure 5 It is arranged in Figure 4 Close up of a conventional wear block and wear pad on a slide.

[0031] Fig. 6A is an isometric illustration of a conventional wear block and wear pad.

[0032] Figure 6B yes Fig. 6A Cross-sectional view of the wear block and wear pad.

[0033] Figure 7 is an isometric illustration of a wear block and wear pad shown mounted on a carriage in accordance with principles of the present inventive concepts.

[0034] Figure 8 is a top cross-sectional view of a gantry system showing wear blocks and wear pads on a carriage and gantry rails arranged in a gantry channel in accordance with the principles of the present inventive concepts.

[0035] Fig. 9 is an isometric illustration of an adjustable wear block in accordance with principles of the present inventive concepts.

[0036] Fig.10 yes Fig. 9 Exploded isometric illustration of an adjustable wear block.

[0037] Fig.11 yes Fig.10 Isometric view of the housing and base of the adjustable wear block.

[0038] Fig.12 yes Fig. 9 Cross-sectional isometric view of the adjustable wear block.

[0039] Figures 13A-13F It is arranged on the slide Fig. 9 The isometric view and isometric cross-sectional view of an adjustable wear block further illustrate a method for adjusting an adjustable wear pad according to principles of the present inventive concepts.

[0040] Fig.14 is an isometric view of another embodiment of a hydraulically adjustable wear block in accordance with principles of present inventive concepts.

[0041] Fig.15 yes Fig.14 Isometric view of a cross section of a hydraulically adjustable wear block.

[0042] Figures 16A-16E is a hydraulically adjustable wear block (e.g. Fig.14 A schematic illustration of a hydraulically adjustable wear block is shown, illustrating a method of operating a hydraulically adjustable wear block according to further principles of the present inventive concept.

[0043] Fig.17 is a schematic illustration of a hydraulically adjustable wear block according to yet another embodiment of the present inventive concepts.

[0044] Fig.18 is a schematic illustration of a hydraulically adjustable wear block according to yet another embodiment of the present inventive concepts.

[0045] Fig.19 is a schematic illustration of a self-adjusting wear block according to another embodiment of the present inventive concept.

[0046] Fig. 20 is an isometric illustration of a self-adjusting wear block in accordance with principles of the present inventive concepts.

[0047] Fig.21 yes Fig. 20 Another isometric illustration of the self-adjusting wear block of Fig. 20 Rotated 180 degrees.

[0048] Fig. 22 It is along Fig. 20 The line 22-22 is intercepted Fig. 20 Isometric illustration of a cross section of the self-adjusting wear block.

[0049] Fig.23 It is along Fig. 20 The line 23-23 is intercepted Fig. 20 Another cross-sectional isometric illustration of the self-adjusting wear block.

[0050] Figures 24A-24C Mounted to the carriage Fig. 20 An isometric illustration of an automatically adjustable wear block and a ramp disposed in a portal channel further illustrates a method of operating an automatically adjustable wear block in accordance with further principles of the present inventive concepts.

[0051] Fig.25A and Fig.25B yes Fig. 20 A close up isometric illustration of an automatically adjustable wear block further illustrates the interaction between a ramp disposed in a gantry channel and the automatically adjustable wear block in accordance with the principles of the present inventive concepts.

[0052] Fig.26 is similar to Fig.25B A close-up of the Fig. 20 When using self-adjusting wear blocks, use shim plates to maintain the proper gap distance.

[0053] Fig. 27 is a schematic illustration of a self-adjusting wear block further self-aligning with a channel surface in accordance with still further principles of the present inventive concepts.

[0054] Fig.28A and Fig.28B is a schematic cross-sectional side view of a self-adjusting wear block that automatically aligns with a channel surface, further illustrating a method of operation in accordance with additional principles of the present inventive concepts.

[0055] Fig.29 is a cross-sectional isometric illustration of a hydraulically adjustable wear block in accordance with still further principles of the present inventive concepts.

[0056] Fig.30 and Fig.31 is an isometric illustration showing a hydraulic pump (grease point) and grease lines for supplying hydraulic oil or grease to a hydraulically adjustable wear block in accordance with still further principles of the present inventive concepts. DETAILED DESCRIPTION

[0057] Example embodiments are described below with reference to the accompanying drawings. Unless otherwise explicitly stated in the drawings, the sizes, positions, etc. of parts, features, elements, etc. and any distances therebetween are not necessarily to scale and may be disproportionate and / or exaggerated for clarity.

[0058] The terms used herein are only for the purpose of describing specific example embodiments, and are not intended to be limited. As used herein, the singular forms "one", "this" and "the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should be recognized that the terms "include", "comprise" and / or "comprises" clearly indicate the existence of stated features, integers, steps, operations, elements and / or parts when used in this specification, but do not exclude the existence or addition of one or more other features, integers, steps, operations, elements, parts and / or their groups. Unless otherwise specified, the range of values ​​includes both the upper and lower limits of the range and any sub-ranges therebetween when described. Unless otherwise indicated, terms such as "first", "second", etc. are only used to distinguish one element from another element. For example, an element may be referred to as a "first element", and similarly, another element may be referred to as a "second element", or vice versa. The section titles used herein are only for the purpose of organization and should not be interpreted as limiting the subject matter described.

[0059] Unless otherwise indicated, the terms "about," "approximately," "substantially," and the like indicate that quantities, sizes, formulations, parameters and other amounts and features are not and do not have to be exact, but may be approximate and / or larger or smaller as desired, reflecting tolerances, conversion factors, rounding, measurement errors, and the like, as well as other factors known to those skilled in the art.

[0060] Spatially related terms such as "right", "left", "below", "bottom", "down", "above", and "upper" may be used herein for convenience of description to describe the relationship of one element or feature to another element or feature as illustrated in the accompanying drawings. It should be recognized that these spatially related terms are intended to include different orientations in addition to the orientations depicted in the accompanying drawings. For example, if the object in the accompanying drawings is turned over, the elements described as being "below" or "below" other elements or features will then be oriented to be "above" the other elements or features. Therefore, the term "below" may, for example, include both an orientation above and an orientation below. Objects may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially related descriptors used herein may be interpreted accordingly.

[0061] Unless expressly indicated otherwise, all connections and all operational connections may be direct or indirect. Similarly, unless expressly indicated otherwise, all connections and all operational connections may be rigid or non-rigid.

[0062] Throughout the text, similar reference numerals refer to similar elements. Therefore, the same or similar reference numerals may be described with reference to other drawings, even if they are neither mentioned nor described in the corresponding drawings. In addition, even elements not marked with reference numerals may be described with reference to other drawings.

[0063] Without departing from the spirit and teachings of the present disclosure, many different forms and embodiments are also feasible, and therefore the present disclosure should not be interpreted as being limited to the example embodiments set forth herein. On the contrary, these example embodiments are provided so that the present disclosure will be comprehensive and complete and convey the scope of the present disclosure to those skilled in the art.

[0064] Figure 1 is an isometric illustration of a frame 115 and mast system 200 for a conventional reach / lift truck 100 . Figure 2 yes Figure 1 A cross-sectional view of the gantry system 200 is shown. Figure 3 yes Figure 1 A close up of area A of the gantry system 200. Figure 4 Can be attached to Figure 1 Isometric illustration of the carriage 220 of the gantry system 200 . Figure 5 It is arranged in Figure 4 A close up of a conventional wear block 300 and wear pad 310 on a carriage 220 of FIG. Fig. 6A yes Figure 5 An isometric illustration of a conventional wear block 300 and a wear pad 310. And, Figure 6B is a cross-sectional view of wear block 300 and wear pad 310 of FIG. 6 .

[0065] First reference Figure 1-6B , a conventional lift truck 100 has a frame 115 on which a gantry system 200 is disposed. A conventional gantry system or lift system 200 includes a carriage 220 having a lift fork (not shown) mounted to the carriage 220. The carriage 220 is raised and lowered along the gantry 210 to pick up and carry a load. Forward and rearward forces on the carriage 220 are absorbed by rollers (or guide bearings) 230 mounted on the carriage 220 and disposed within the gantry channel 214. A desired amount of clearance is provided between the rollers 230 and the front and rear channel sidewalls so that only one sidewall or the other sidewall contacts the rollers 230 in response to forward or rearward forces on the carriage 220 to absorb the force and keep the rollers 230 positioned within the gantry channel 214 as the carriage 220 is raised and lowered.

[0066] The top and bottom wear blocks 300 are arranged on the carriage 220 between the carriage 220 and the inner wall 214a of the mast channel to prevent the inner wall 214a of the mast channel 214 from directly hitting the carriage components, such as the carriage rollers 230. The wear blocks 300 are generally arranged as far away as possible (substantially close to the carriage rollers 230) to absorb the lateral (transverse) forces on the carriage 220 that occur during the lifting of the load or during the travel of the loading and unloading vehicle with the load on the lifting forks. The wear blocks 300 are attached to the carriage 220 by welding, bolts or other mechanical or chemical connections. The wear pad 310 is arranged in the wear block 300 and is fixed by a threaded bolt 302, which is arranged through a hole 312 in the center of the wear pad 310 and is screwed into a receiving hole 304 in the base of the wear block 300. In a multi-stage elevator, wear blocks 300 may also be arranged at the top and bottom of the additional mast channels 216 to absorb lateral forces on the mast rails 212 and prevent the mast channel walls 216a from striking mast components such as rollers 230.

[0067] A certain gap must be maintained between the gantry channel inner walls 214a, 216a and the wear pad 310 to allow the lift system 200 to operate normally. The wear surface (outermost surface) 310a of the wear pad 310 must therefore be maintained at a desired distance (e.g., gap) from the channel walls 214a, 216a to absorb lateral forces without impairing the lift operation. However, since the wear pad 310 is designed to wear out over time, the distance between the wear pad 310 and the channel walls 214a, 216a is difficult to maintain at a constant level. If the gap is too large, it will allow the carriage 220 and / or the gantry rail 212 to have excessive play (lateral movement) when raising and lowering, resulting in additional wear on the lift components. If the gap is too small, sticking or jamming may occur during the lifting and lowering operation, interfering with the normal operation of the lift system 200. If the wear pad 310 is completely worn out, metal-to-metal contact may occur, which may damage the gantry or carriage components. However, as previously mentioned, conventional wear pads 310 can be difficult to access for repair, adjustment, or replacement.

[0068] Figure 7 is an isometric view of a wear block 400 and a wear pad 410 shown mounted on carriage 220 in accordance with principles of the present inventive concepts. Figure 8 is a top cross-sectional view of a gantry system 200 showing wear blocks 400 and wear pads 410 disposed on carriages 220 and gantry rails 210 in gantry channels 214, 216 in accordance with principles of the present inventive concepts. Fig. 9 is an isometric illustration of an adjustable wear block 400 in accordance with principles of the present inventive concepts. Fig.10 yes Fig. 9 An exploded isometric illustration of an adjustable wear block 400. Fig.11 yes Fig.10 An isometric view of the housing 402 and base 404 of the adjustable wear block 400. And, Fig.12 yes Fig. 9 A cross-sectional isometric view of adjustable wear block 400 .

[0069] Reference now Figure 7-12 In accordance with the principles of the present invention, the wear block 400 is designed and mounted to the slide 220 or the gantry rail 210 in such a manner that the height of the wear pad 410 is easily adjusted to position the wear surface 410a in the wear pad 410 at an appropriate distance (gap) from the opposing channel walls 214a, 216a to absorb lateral forces and prevent damage to the gantry components without interfering with the lifting operation.

[0070] More specifically, in one embodiment, an adjustable wear block 400 is provided having a wear surface 410a position (or wear pad height, distance from the surface) that can be easily adjusted. A circular housing 402 having internal threads 403 is attached to the carriage 220 to be disposed between the carriage 220 and the gantry channel wall 214a when the carriage 220 is installed in the gantry system 200. The wear block housing 402 can be attached to the carriage 220 by welding, bolts, adhesives, or other mechanical or chemical connections. A threaded base 404 (formed of metal or other rigid material) having threads 405 that match the housing threads 403 is disposed in the housing 402 so that its position within the housing 402 can be adjusted by rotating the metal base 404 relative to the housing 402. The wear pad 410 is attached to the base 404 using one or more fasteners, adhesives, or other connection mechanisms. In one embodiment, three threaded bolts 430 are secured through holes 412 in wear pad 410 to mounting holes 406 in base 404 to secure wear pad 410 to rotatable base 404. A hexagonal hole or other tool receptacle 408 may be disposed in or through the center of base 404 to allow for insertion of a tool (e.g., a hex wrench or other tool) 440 (see FIG. Figures 13E-13F ) is inserted therein to rotate the base 404 relative to the housing 402.

[0071] Adjustable wear block 400 can be made to be easily retrofitted to existing lift trucks 100, such as by replicating the connection mechanism of conventional wear block 300. For example, screw holes can be arranged on the adjustable wear block at locations that match mounting screws on or through the carriage or gantry mounting surface. Additional holes can also be formed through the carriage or gantry mounting wall to provide access to locking holes and tool receptacles.

[0072] Figures 13A-13F is arranged on the wall 224 of the carriage 220 Fig. 9 The isometric view and isometric cross-sectional view of the adjustable wear block 400 further illustrate the method for adjusting the adjustable wear block 400 according to the principles of the present inventive concept. Figures 13A-13F , tool receptacle holes 224a may be arranged through the mounting wall 224 of the carriage 220 or the gantry rail 210 to allow the height of the wear pad 410 to be easily adjusted using a tool 440 without removing the carriage 220 or other gantry system 200 components. One or more locking holes 407 (preferably, a series or pattern of locking holes 407) may be provided in the bottom of the base 404 to receive one or more locking screws or pins 432, which prevent the base 404 from rotating when the locking screws 432 are inserted into the locking holes 407 through the mounting wall 224. The locking holes 407 may be arranged in a circular pattern, for example, near the outer edge of the base 404 to allow the base 404 to be locked in any one of a plurality of different rotational positions. The locking screws 432 may be, for example, threaded bolts that are threaded into the threaded locking holes 407. A matching hole 224b may be disposed through the carriage or gantry side wall 224 to which the wear block 410 is attached to receive a locking screw or pin 432. A plug or cap 436 may be used to cover the tool receptacle hole 224a in the carriage or gantry wall 224 before and after adjusting the height of the wear pad 410 to prevent moisture or other contaminants from entering the wear block 400. An O-ring 414 may also be disposed between the wear pad 410 and the housing 402 (at Fig.10 and Fig.12 (shown in the middle figure) to prevent moisture and other contaminants from entering the housing 402.

[0073] In one embodiment, to adjust the height of the wear pad 410, the locking screw 432 and cover 436 are removed from the wall 224, releasing the wear pad base 404 and allowing access to the tool receptacle 408. The tool 440 is inserted into the tool receptacle 408 in the base 404 through the hole 224a, and the base 404 is rotated to adjust the height of the wear pad 410. As the base 404 is rotated, the wear pad 410 extends further from the housing 402 or retracts into the housing, depending on the direction of rotation of the base 404. The gap of the wear pad 410 can be set to the desired distance by first adjusting the wear pad 410 to a height where the wear surface 410a contacts the gantry channel walls 214a, 216a (e.g., by adjusting the wear surface 410a to a height where the wear surface 410a contacts the gantry channel walls 214a, 216a). Fig.13E ), and then rotating the base 404 backward (by rotating the tool clockwise as indicated in FIG. Fig.13F40) a certain amount (e.g., two full rotations of adjustment tool 440 (and therefore base 404)). A label 442 or other marking may be provided around hole 224a for adjustment tool 440, having a scale indicating the relationship between rotation of tool 440 and height adjustment (or linear travel distance) of wear pad 410. In one embodiment, base threads 405 and housing threads 403 each have a 6 mm pitch, and each segment 444 on label 442 may represent 0.5 mm of linear travel of wear pad 410.

[0074] Of course, alternative embodiments are contemplated and within the scope of the inventive concept. For example, the wear block housing need not be circular, so long as it provides an adjustable wear pad surface height that can be adjusted from a convenient location (e.g., by the rear side of the wear block of the mounting wall). For example, a rectangular wear block housing may be used with a wear pad mounted on an adjustable base, the height of which may be extended and retracted using one or more screws mounted through one or more holes in the base. In addition, a tool receptacle need not necessarily be provided in the base, so long as the mechanism for adjusting the height of the wear pad is provided in a convenient location (e.g., on the opposite side of the carriage or gantry wall). In an alternative, a knob, bolt, rod, handle, or other mechanism may be directly connected to the base and extend through a hole in the carriage or gantry wall to allow the base to rotate without the need for a separate tool, or it may allow a tool to adjust the end of the knob, bolt, rod, handle, or other mechanism without the need for the tool to extend into and / or through the receptacle in the wall or base.

[0075] Fig.14 is an isometric view of another embodiment of a hydraulically adjustable wear block 500 in accordance with principles of present inventive concepts. Fig.15 yes Fig.14 A cross-sectional view of a hydraulically adjustable wear block 500. Figures 16A-16E is a schematic illustration of a hydraulically adjustable wear block 500 illustrating a method of operating the hydraulically adjustable wear block 500 in accordance with further principles of the present inventive concepts.

[0076] Reference now Figure 14-16E In another embodiment, the height of the wear pad 510 can be hydraulically adjusted to maintain a desired gap with the mast channel wall 214a. In one embodiment, the wear pad 510 is arranged on a hydraulic piston 520 within the wear block 500. The cross-sections of the wear pad 510 and the hydraulic piston 520 can be, for example, the same size and shape, or the hydraulic piston 520 can also be arranged to push against any other desired shape of substrate or wear pad. In some embodiments, the wear pad 510 itself can be the hydraulic piston 520.

[0077] A hydraulic fluid valve system 600 may be provided that ensures that the wear pad 510 is arranged at a desired clearance C from the mast channel wall 214a. An oil feed 602 may be provided to feed oil (or other suitable hydraulic fluid) into the hydraulic cylinder 610 behind the hydraulic piston 520 that drives the wear pad 510. The oil feed 602 is preferably supplied through a first cylinder 604 having a piston 606 disposed therein that is able to slide forward and backward over the entire length of the first cylinder 604. The first cylinder 604 may have a fluid volume that is defined such that one stroke of the piston 606 corresponds to a predetermined linear travel distance of the wear pad 510. The predetermined linear travel distance may be, for example, approximately about 2 mm. A check valve 608 may be disposed through the piston 606 so that oil is supplied to the hydraulic cylinder 610 through the piston 606 after the piston 606 has traveled sufficiently forward within the first cylinder 604. The check valve 608 may include a preloaded spring 609 that requires a predetermined force (pressure) to open. The predetermined pressure may be, for example, approximately 1 bar. The check valve 608 prevents oil from returning to the oil feed 602.

[0078] In operation, oil is supplied from oil feed 602 to first piston 606 in first cylinder 604. Piston 606 is driven forward through first cylinder 604 until it reaches the end of first cylinder 604. As piston 606 travels forward, the piston drives fluid from first cylinder 604 into hydraulic cylinder 610 behind piston 520. As the fluid enters hydraulic cylinder 610, the fluid forces piston 520 and wear pad 510 outward. Since the volume of first cylinder 604 is defined so that the full movement of piston 606 is equal to 2 mm (or other predetermined amount) of linear movement of wear pad 510, wear pad 510 will be forced to move a linear distance of 2 mm due to the movement of piston 606, or until it contacts mast channel wall 214a. If, after piston 606 has traveled its full distance, there is still a gap between wear pad 510 and channel wall 214a, check valve 608 will open and allow additional oil to be supplied to hydraulic cylinder 610 through check valve 606, causing wear pad 510 to continue to move until it contacts mast channel wall 214b. After wear pad 510 contacts mast channel wall 214a, hydraulic piston 520 cannot move further and hydraulic cylinder 610 cannot receive more oil. When cylinder 610 cannot receive more oil, oil feed 602 then stops or is shut off. With oil feed 602 shut off, piston 606 in first cylinder 604 is then free to move back to its original position (e.g., when force is applied to wear pad 510). Fig.16E). When the force from the gantry system 200 acts on the wear pad 510, the wear pad 510 pushes the fluid from the hydraulic cylinder 610 back into the first cylinder 604, driving the piston 606 back toward its original position. And, since the volume of the first cylinder 604 corresponds to a 2 mm straight travel distance of the wear pad 510, the wear pad 510 can be forced back up to 2 mm before the piston 606 reaches its original position, and further movement of the wear pad 510 is blocked. In this way, by selecting the desired fluid volume for the first cylinder 604, the gap C can be set to a predetermined distance.

[0079] Fig.17 is a schematic illustration of a hydraulically adjustable wear block 500A according to yet another embodiment of the present inventive concepts. Fig.18 is a schematic illustration of a hydraulically adjustable wear block 500B according to still another embodiment of the present inventive concepts. Fig.19 is a schematic illustration of a self-adjusting wear block 700 according to another embodiment of the present inventive concepts.

[0080] In other embodiments of hydraulically adjustable wear blocks 500A, 500B according to further aspects of the present concepts, the amount of gap C may be made adjustable by providing additional volume in first cylinder 604. Referring now additionally to Figure 17-18 , the first cylinder 604 may be provided with an additional volume and an adjustment screw 612 or other travel limiter for setting the travel distance of the first piston 606 and thus the corresponding linear travel distance of the wear pad 510. By adjusting the travel distance of the piston 606 and thus the linear travel distance of the wear pad 510 allowed, the gap C can be adjusted and set as needed.

[0081] Specific reference Fig.18 In one embodiment of the hydraulically adjustable wear block 500C, a second piston (centering piston) 616 may be provided that acts as or controls a valve 620 to control when oil is supplied to the hydraulic cylinder 610, such as when the mast 210 is centered. The second piston 616 may be disposed in the second cylinder 614 with a retraction spring 618 biasing it toward a closed valve position. The oil feed 602 may be selectively supplied to the first cylinder 604 through the second cylinder 614 only when the second piston 616 opens the valve 620. When the mast 210 is centered, the second piston 616 may open the valve 620 to allow oil to flow into the first cylinder 604. In this way, the position of the wear pad 510 is set when the mast 210 is centered. A dump (or dump valve) 613 may be provided from a first end of the first cylinder 604 (opposite to the hydraulic cylinder 610) to allow oil to be released from the first end of the first cylinder 602. The one-way dump valve 613 allows the first piston 606 to move rearward until it contacts the set screw 612 .

[0082] Fig.19 is a schematic illustration of a self-adjusting wear block 700 according to another embodiment of the present inventive concepts. Fig. 20 is an isometric illustration of a self-adjusting wear block 700 in accordance with further principles of the present inventive concepts. Fig.21 yes Fig. 20 Another isometric illustration of the automatically adjusting wear block 700. Fig. 22 yes Fig. 20 A cross-sectional isometric illustration of the self-adjusting wear block 700. Fig.23 yes Fig. 20 Another cross-sectional isometric illustration of the self-adjusting wear block 700. Figures 24A-24C It is mounted on the carriage 220 Fig. 20 An isometric illustration of automatically adjusting wear block 700 and ramp 910 disposed in mast channel 214 further illustrates a method of operating automatically adjusting wear block 700 in accordance with further principles of the present inventive concepts. Fig.25A and Fig.25B is a close up isometric illustration of automatically adjusting wear block 700 further illustrating the interaction between ramp 910 disposed in mast channel 214 and automatically adjusting wear block 700 in accordance with principles of the present inventive concepts. Fig.26 is similar to Fig.25B A close-up of the Fig. 20 When using the self-adjusting wear block 700, a shim plate 920 is used to maintain the proper gap distance.

[0083] Now refer to Figure 19-26 According to still further principles of the present inventive concept, an automatically adjustable wear block 700 may be provided that automatically adjusts the height of a wear pad 710 to provide a desired clearance with a mast channel wall 214a at a predetermined travel point of a mast system 200. In one embodiment, the automatically adjustable wear block 700 may include a wear block housing 702, a wear pad 710 disposed in the housing 702, and a hydraulic system 800 for adjusting the height of the wear pad 710. A button 805 may be disposed on the wear block housing 702 beside the wear pad 710 to force the wear pad 710 outward when pressed. A ramp 910 may be provided along the mast channel 214, 216 to activate the button 805 when the carriage / gantry 220 / 210 reaches a certain desired adjustment point along its travel.

[0084] In one embodiment, a hydraulic piston 806 in the master cylinder 804 is connected to a button 805. A ramp 910 in the mast channel 214, 216 is configured to contact the button 805 at a desired adjustment point during travel of the carriage / gantry 220 / 210. When the ramp 910 contacts the button 805, the button 805 is depressed and the connected hydraulic piston 806 forces hydraulic fluid from the master cylinder 804 into the slave cylinder 810, driving the second hydraulic piston 720, which forces the wear pad 710 outward. A retaining spring 712 may be provided between the wear block housing 702 and the wear pad 710 to retain the wear pad 710 within the wear block housing 702. A shim plate 920 may be provided in the mast channel 214, 216 at an adjustment point in travel of the carriage / gantry 220 / 210 to ensure that the wear pad surface 710a only extends to the shim plate 920. This maintains the proper gap between the upper surface 710a of the wear pad 710 and the portal channel wall 214a. Alternatively, a Figure 16A-18 One or more methods and mechanisms similar to those described above can be used to automatically set the appropriate gap distance. Check valves 803, 808 can be provided between the fluid reservoir 802 and the master cylinder 804 and between the master cylinder 804 and the slave cylinder 810 to ensure that hydraulic fluid flows in only one direction.

[0085] Fig. 27 is a schematic illustration of a self-adjusting wear block 1000 that is otherwise automatically aligned with channel surface 214a in accordance with still further principles of the present inventive concepts. Fig.28A and Fig.28B is a somewhat schematic cross-sectional side view of a self-adjusting wear block 1000 automatically aligning with channel surfaces 214a, 216a, further illustrating the method of operation in accordance with further principles of the present inventive concepts.

[0086] Referring now additionally to FIGS. 24-28B , in an alternative embodiment, the automatically adjustable wear block 1000 may also automatically align with the channel walls 214a, 216a. In this embodiment, two or more slave cylinders 1110, 1112 may be provided along the length of the wear block 1000 to drive the pistons 1020, 1022 in different regions along the wear pad 1010. By providing multiple slave cylinders 1110, 1112 connected to the pistons 1020, 1022 in different regions of the wear pad 1010, each individual region of the wear pad 1010 may be driven the appropriate amount to contact the shim plate 920 or the channel walls 214a, 216a. When a first side of the wear pad 1010 contacts the shim plate 920 or the channel walls 214a, 216a, the force on that side (indicated by arrow 1230) prevents the piston 1022 and the wear pad 1010 on that side from moving further. However, at the same time, the other piston 1020 can continue to move until the wear pad 1010 contacts the shim plate 920 or the walls 214a, 216a on that side. In this way, different areas of the wear pad 1010 can extend different amounts from the wear block 1000 to better match the alignment of the channel walls 214a, 216a.

[0087] Fig.29 is a cross-sectional isometric illustration of a hydraulically adjustable wear block 1200 in accordance with still further principles of the present inventive concepts. Fig.29 , the hydraulically adjustable wear block may include a housing 1202, a wear pad 1210, and a hydraulic piston 1220. In some embodiments, the hydraulic piston 1220 may be the wear pad 1210. O-rings 1230, 1232 may be provided around the piston 1220 to prevent leakage of hydraulic fluid. Hydraulic oil or grease may be provided to a cylinder 1240 in the housing 1202 through a grease fitting 1242 to drive the piston 1220 and the wear pad 1210 outward. The wear pad 1210 may be connected to the piston 1220 by one or more threaded bolts 1212.

[0088] In operation, piston 1220 and wear pad 1210 are slidably disposed in receptacle (cylinder) 1240 of wear block 1200. One or more O-rings 1230, 1232 are disposed around the piston to seal against the wall of receptacle 1240 to prevent leakage of hydraulic oil or grease. Oil / grease fitting 1242 is disposed at the bottom of wear block 1200 to supply oil / grease to receptacle 1240 to drive piston 1220 and connected wear pad 1210 outward until it contacts a shim plate (not shown) or otherwise reaches a desired position.

[0089] Fig.30 and Fig.311 is an isometric illustration showing a hydraulic pump (grease point) 1300 and grease lines 1310, 1312 for supplying hydraulic oil or grease to a hydraulically adjustable wear block 1320 arranged on a carriage 220 in accordance with still further principles of the present inventive concept. Fig.30 and Fig.31 , one or more grease lines or supply lines 1310, 1312 may be used to supply oil / grease to one or more of the wear blocks 1320 from a single grease point (supply point) 1300 or multiple grease points 1300. In this embodiment, the hydraulic pump 1300 is configured to supply hydraulic fluid to the grease lines when the slide 220 is raised to its highest position in the mast. The operator may use a grease gun or other hydraulic fluid supply (i.e., a hydraulic pump) to force oil / grease into the grease point 1300 and drive the piston in the wear block 1320 outward through the grease lines 1310, 1312. Shim plates may be used to provide a stopping point for the outward movement of the wear pads 1320 and ensure proper clearance with the channel walls 214a, 216a. Alternatively, a shim plate may be used with respect to Figure 16A-18 One or more of the methods described can be used to automatically set the appropriate gap.

[0090] summary

[0091] Various other modifications are also contemplated, and many variations of the specific designs identified above are possible without departing from the spirit and scope of the inventive concept. Having described and illustrated the principles of the inventive concept in terms of different preferred embodiments of the invention, it should be apparent that the invention may be modified in arrangement and detail without departing from these principles. In particular, it should be apparent that many variations of the shape and configuration of the wear block are possible without departing from these principles.

[0092] The terms and descriptions used above are stated only in an illustrative and exemplary manner and are not intended to be limiting. Those skilled in the art will recognize that many variations, enhancements and modifications of the concept described herein are also feasible without departing from the basic principles of the present invention. For example, those skilled in the art will appreciate that the subject matter of any statement or paragraph may also be combined with some or all of the subject matter in other statements or paragraphs, unless such a combination is mutually exclusive. Therefore, the scope of the present invention should only be determined by the appended claims, the claims proposed in the continuation of the patent application, and the equivalents of the aforementioned claims.

Claims

1. An adjustable wear block (400) for a gantry system (200), the adjustable wear block (400) comprising: a housing (402) configured to be secured to a carriage (220) or a mast rail (210); a wear pad (410) disposed within the housing (402) and extending a selected distance from the housing (402) such that the wear pad (410) can absorb lateral forces on the carriage (220) or the gantry rail (210) when secured to the carriage (220) or the gantry rail (210), and wherein the distance that the wear pad (410) extends from the housing (402) can be adjusted without removing the wear pad (410) from the wear block (400) and without removing the wear block (400) from the slide (220) or the portal rail (210) after the wear block has been secured to the slide or portal rail.

2. The adjustable wear block (400) according to claim 1, further comprising: An adjustable base (404) is disposed within a housing (402), wherein a wear pad (410) is attached to the adjustable base (404), and wherein a position of the adjustable base (404) is adjustable within the housing (402).

3. The adjustable wear block (400) according to claim 1 or 2, wherein: The wear pad (410), the adjustable base (404), and the interior of the housing (402) each have a circular cross-section.

4. The adjustable wear block (400) according to claim 3, wherein: The adjustable base (404) includes a thread (405) arranged on the outside of the base (402), and wherein the housing (402) includes a matching thread (403), so that the position of the base (404) within the housing (402) can be adjusted by rotating the base (404) relative to the housing (402).

5. The adjustable wear block (400) according to claim 1 or 2, wherein: The base (404) includes a tool receptacle (408) configured to receive a tool (440) that can be used to adjust the position of the base (404) relative to the housing (402).

6. The adjustable wear block (400) according to claim 5, wherein: The carriage (220) or gantry rail (210) to which the wear block (400) is secured includes an aperture to provide access to a tool receptacle (408) in the wear block base (404).

7. The adjustable wear block (400) according to claim 2, 3, 4, 5 or 6, further comprising: A locking mechanism (432) is configured to lock the position of the adjustable base (404) within the housing (402).

8. The adjustable wear block (400) according to claim 7, wherein: The locking mechanism (432) includes one or more locking screws (432) configured to prevent the adjustable base (404) from moving relative to the housing (402).

9. The adjustable wear block (500) according to claim 1, 2, 3, 4, 5, 6 or 7, further comprising: A hydraulic piston (520) is disposed within a hydraulic cylinder (610) formed in the housing (402) and is configured to adjust the position of the wear pad (510) within the housing (402).

10. The adjustable wear block (500) according to claim 9, wherein: The hydraulic piston (520) is automatically actuated at a specific point in the travel of the carriage (220) or gantry rail (210) to which it is fixed.

11. The adjustable wear block (500) according to claim 9 or 10, further comprising: A mechanism (600) that automatically sets a desired gap between a wear pad (510) and a gantry channel (214, 216) wall when a wear block (500) is secured to a carriage (220) or gantry rail (210) and the wear pad (510) is adjusted.

12. A method of adjusting the height of a wear pad (410) arranged in a wear block (400) fixed to a carriage (220) or a mast rail (210), the method comprising: Inserting an adjustment tool (440) through a hole in the carriage (220) or gantry rail (210) and into a tool receptacle (408) in the base (404) of the wear block housing (402); and The adjustment tool (440) is rotated to adjust the position of the base (404) relative to the wear block housing (402), wherein the height of the wear pad (410) is adjusted together with the position of the base (404).

13. The method according to claim 12, further comprising: The adjustment tool (440) is rotated in a first direction until the wear pad (410) contacts the channel wall (214a, 216a), and then the adjustment tool (440) is rotated in an opposite second direction to provide a gap between the channel wall (214a, 216a) and the wear pad (410).

14. The method according to claim 12 or 13, wherein: A plurality of markings (442) are provided about the hole (224a) in the carriage (220) or gantry rail (210) wall to indicate the linear distance of travel of the wear pad (410) corresponding to the rotational movement of the adjustment tool (440).

15. The method according to claim 14, wherein: Each of the plurality of markings (442) corresponds to a linear travel distance of approximately 0.5 mm.

16. The method of claim 12, 13, 14 or 15, further comprising: Prior to rotating the adjustment tool (440), one or more locking screws (432) that lock the position of the base (404) relative to the wear block housing (402) are removed.

17. A hydraulically adjustable wear block (500, 700, 1000), comprising: Housing (402, 702); a wear pad (510, 710, 1010) disposed within the housing (402, 702); as well as A hydraulic piston (520, 720, 1020, 1022) is disposed within the housing (402, 702) and is configured to drive the position of the wear pad (510, 710, 1010) relative to the housing (402, 702).

18. The hydraulically adjustable wear block (500, 700, 1000) of claim 17, further comprising: a first cylinder (604) having a predetermined volume; a first piston (606) disposed in the first cylinder (604); as well as a check valve (608) disposed across the first piston (606), wherein the first cylinder (604) supplies hydraulic fluid to a hydraulic cylinder (610) accommodating the hydraulic piston (520) such that when the first piston (606) moves from a first position to a second position within the first cylinder (604), hydraulic fluid is supplied from the first cylinder (604) to the hydraulic cylinder (610), and wherein, when the first piston (606) reaches the second position within the first cylinder (604), additional hydraulic fluid is supplied from a fluid source to the hydraulic cylinder (610) through a check valve (608) in the first piston (606).

19. The hydraulically adjustable wear block (500, 700, 1000) according to claim 18, wherein: The hydraulic fluid supply is stopped when the wear pad (510) contacts the portal surface (214a, 216a), wherein when the hydraulic fluid supply is shut off, the first piston (606) is allowed to move from the second position back to the first position, and wherein the predetermined volume of the first cylinder (604) corresponds to a desired gap between the wear pad (510) and the portal surface (214a, 216a) so that the force on the wear pad (510) drives the first piston (606) back toward its first position to establish the desired gap between the portal surface (214a, 216a) and the wear pad (510).

20. The hydraulically adjustable wear block (500, 700, 1000) of claim 17, further comprising: A plurality of hydraulic pistons (1020, 1022) are each arranged in communication with a different region of the wear pad (710, 1010) so that the contact surface (710a) of the wear pad (710, 1010) can automatically adjust to the orientation of the mast surface (214a, 216a).

21. The hydraulically adjustable wear block (500, 700, 1000) of claim 17, further comprising: A button (805) is arranged on the wear block housing (402) and is configured to contact a ramp (910) arranged in the mast channel (214, 216), wherein when the ramp (910) contacts the button (805), hydraulic fluid is driven from the master cylinder (804) to the slave cylinder (801, 1010, 1112) arranged behind the hydraulic piston (806) to drive the wear pads (510, 710, 1010) outward until the wear pads contact the channel wall (214a, 216a) or the shim plate (920).

22. The hydraulically adjustable wear block (500, 700, 1000) according to claim 21, wherein: The ramps (910) are arranged at desired locations along the mast channels (214, 216) so that automatic adjustment of the wear pad height occurs at predetermined mast travel points.

23. The hydraulically adjustable wear block (500, 700, 1000) of claim 17, further comprising: One or more fluid supply points at which hydraulic fluid can be supplied to the wear block (500, 700, 1000) via one or more fluid supply lines.

24. The hydraulically adjustable wear block (500, 700, 1000) according to claim 23, wherein: A fluid supply line is connected to the plurality of wear blocks (500, 700, 1000) to supply hydraulic fluid to the wear blocks (500, 700, 1000) from a single fluid supply point.

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