Hybrid microtrencher wheel

Abstract

A hybrid microtrencher wheel comprising a disc-shaped carrier defining a central rotation axis and an outer perimeter. A plurality of primary cutters are secured to the outer perimeter of the carrier. A plurality of gage cutters are secured to the outer perimeter of the carrier. The plurality of primary cutters have a first material construction different than a second material construction of the plurality of gage cutters. The plurality of primary cutters are arranged in an inner row that defines an overall width less than a gage width of the microtrencher wheel. The plurality of gage cutters define an overall width equal to the gage width of the microtrencher wheel. A swept diameter defined by rotation of the plurality of gage cutters about the central rotation axis does not exceed a swept diameter defined by rotation of the plurality of primary cutters.

Description

Attorney Docket No: 489825-0022 -WO01HYBRID MICROTRENCHER WHEELCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims benefit of priority to co-pending U.S. ProvisionalPatent Application No. 63 / 718,422, filed on November 8, 2024, the entire contents of which are incorporated by reference herein.BACKGROUND

[0002] The present disclosure relates generally to excavation and cutting tools such as trenching machines and microtrenching machines C‘microtrenchers?’).

[0003] Microtrenchers are known in the art and frequently used to enable the installation of cables through a road surface, including asphalt and concrete, and the base material. As such, the microtrencher is used to cut a narrow trench (e.g., 'A inch wide to 3 inches) into the road surface. After the trench has been cut, the cable, conduit for receiving cable, or other product is then installed within the trench. Thereafter, the trench is backfilled to repair the roadway.

[0004] A microtrencher typically includes a cutting tool in the form of a cutting or trenching wheel. The cutting wheel includes a circular carrier to which a plurality of cutting elements are mounted. The cutting wheel is rotated such that the cutting teeth engage the surface to be cut to form the desired trench. A variety of microtrencher cutter wheel constructions with various arrangements of cutting elements are known in the art, but there remains a need for a microtrencher cutter wheel that has superior durability for long life, without excessively increasing cost, and has the ability to reliably create a clear trench that holds gage.SUMMARY

[0005] In one aspect, the invention provides a hybrid microtrencher wheel comprising a disc-shaped carrier defining a central rotation axis and an outer perimeter. A plurality of primary cutters are secured to the outer perimeter of the carrier. A plurality of gage cutters are secured to the outer perimeter of the carrier. The plurality of primary cutters have a first material construction different than a second material construction of the plurality of gage cutters. The plurality of primaryAtorney Docket No: 489825-0022 -WO01 cuters are arranged in an inner row that defines an overall width less than a gage width of the microtrencher wheel. The plurality of gage cuters define an overall width equal to the gage width of the microtrencher wheel. A swept diameter defined by rotation of the plurality of gage cuters about the central rotation axis does not exceed a swept diameter defined by rotation of the plurality of primary cuters.

[0006] In another aspect, the invention provides a method of operating a microtrencher including the hybrid microtrencher wheel to form a trench in a road surface.

[0007] In another aspect, the invention provides a hybrid microtrencher wheel comprising a disc-shaped carrier defining a central rotation axis and an outer perimeter. A plurality of primary cuters are secured to the outer perimeter of the carrier. A plurality of gage cuters are secured to the outer perimeter of the carrier to define a gage width of the microtrencher wheel. The plurality’ of primary cuters have a first material construction different than a second material construction of the plurality of gage cuters. The gage width is 7-12 percent larger than an overall width defined by the plurality' of primary cuters. A swept diameter defined by rotation of the plurality of primary’ cuters about the central rotation axis is equal to 1 to 1.01 times a swept diameter defined by rotation of the plurality’ of gage cuters.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. l is a perspective view of a microtrencher according to one aspect of the present disclosure.

[0009] FIG. 2 is a perspective view of a hybrid cuting wheel of the microtrencher according to one aspect of the present disclosure.

[0010] FIG. 3 is a detail view of a peripheral portion of the hybrid cuting wheel.

[0011] FIG. 4 is a partially exploded view of the peripheral portion of the hybrid cutting wheel of FIG. 3.

[0012] FIG. 5 is a front view of a botom portion of the hybrid cuting wheel.Attorney Docket No: 489825-0022 -WO01

[0013] FIG. 6 is a side elevation view of the bottom portion of the hybrid cutting wheel.

[0014] FIG. 7 is a perspective view of a peripheral portion of a hybrid cutting wheel of a second construction of the present disclosure.

[0015] FIG. 8 is a front view of a bottom portion of the hybrid cutting wheel of FIG. 7.

[0016] FIG. 9 is side elevation view of the bottom portion of the hybrid cutting wheel of FIG. 7.

[0017] FIG. 10 is a perspective view of a peripheral portion of a hy brid cutting wheel of a third construction of the present disclosure.

[0018] FIG. 11 is a front view of a bottom portion of the hybrid cutting wheel of FIG. 10.

[0019] FIG. 12 is a side elevation view of the bottom portion of the hybrid cutting wheel of FIG. 10.DETAILED DESCRIPTION

[0020] Before any embodiments of the present invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following draw ings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.

[0021] FIG. 1 shows an example of a trenching machine 20 ('‘microtrencher") in accordance with principles of the present disclosure. The microtrencher 20 is shown being pulled by a propelling vehicle 22 (e.g., tractor, truck or other vehicle). The microtrencher 20 is depicted as an attachment mounted at an offset configuration relative to the propelling vehicle 22 (e g., the microtrencher 20 is shown offset to the right side of the propelling vehicle 22). The microtrencher 20 is connected to the propelling vehicle 22 at a front pivot location 24 that allows the microtrencher 20 to pivot relative to the propelling machine 22 about a vertical front pivot axis 26. TheAttorney Docket No: 489825-0022 -WO01 trenching machine 20 also includes a rear guide component 28 that assists in encouraging the rear of the microtrencher 20 to track at a desired position (e.g.. directly behind) relative to the front pivot axis 26 of the microtrencher 20. As described in further detail below, a rotating cutting device of the microtrencher 20 operates during forward travel of the propelling vehicle to cut a small trench 37 into or through a surface 32 (e.g.. a road surface, such as asphalt or concrete).

[0022] During some trenching operations, it is desirable to remove cuttings from the trench 37 as the trench is excavated. In this regard, a vacuum system can be used to evacuate cuttings / debris from the trench 37. As shown in FIG. 1, the evacuation system can include a vacuum hose 39 coupled to the trenching machine 20 and in fluid communication with a source of vacuum 41 for carrying the cuttings / debris from the trench 37 to a collection tank 43. In certain embodiments, the source of vacuum 41 and the collection tank 43 can be carried by a separate vehicle (e.g., a truck) driven next to. behind or in front of the propelling vehicle 22. In other embodiments, the source of vacuum 41 and collection tank 43 may be carried by the propelling vehicle 22.

[0023] The microtrencher 20 can also include a feed arrangement 40 mounted adjacent to a rear end of the microtrencher 20. The feed arrangement 40 can be configured to feed product 44 (e.g., communications cable, conduit, etc.) into the trench at a location behind the microtrencher 20. During trenching operations, the feed arrangement 40 can be configured to concurrently feed product into the trench behind the trenching machine 20 as the microtrencher 20 trenches in a forward direction 45. In certain embodiments, product such as telecommunications cable can be paid off a spool and fed through the feed arrangement 40. In certain embodiments, the feed arrangement can include a conduit that extends downwardly into the trench 37 at a location rearward of the rear guide component 28. The product 44 can be fed through the interior of the conduit and into the trench 37.

[0024] The microtrencher 20 includes a ground-engaging rotatable component referred to herein as a cutting wheel system 100, and also a cutting wheel, microtrencher wheel, or hybrid microtrencher wheel. An example hybrid microtrencher wheel 100 shown in FIGS. 2-6 includes a disc-shaped carrier 110 having an outer perimeter 112 to w hich a plurality of cutting devices are mounted. InAttorney Docket No: 489825-0022 -WO01 some implementations, the cutting devices include at least two different types of cutting teeth 120 (or "cutlers’') that are mounted, directly or indirectly, to the carrier 110. The microtrencher wheel 100 is rotated about a central axis 102 in a circumferential (forward) direction 104 by a drive mechanism such as a hydraulic motor. As such, the carrier 110 can include one or more drive features (e.g., openings) coupled with the drive mechanism. When rotated, the cutting teeth 120 engage the surface to cut the trench 37. The trench 37 is generally formed by the cutting teeth 120 and not the carrier 110. The cutting teeth 120 are distributed along the perimeter 112 of the carrier 110 according to a repeated pattern.

[0025] In the first example of FIGS. 2-6, the cutting teeth 120 are mounted to the outer perimeter 112 of the carrier 110 indirectly. The cutting teeth 120 are subdivided into circumferential sections or groups 130, each of which includes a mounting substrate 132. Each mounting substrate 132 is an arcuate circumferential segment securable to the outer perimeter (e.g.. by welding or removable fastener(s)). Each mounting substrate 132 can support a plurality of the cutting teeth 120. Each mounting substrate 132 supports at least one primary cutter 120A and at least one secondary' or gage cutter 120B. The gage cutters 120B can have a construction different than a construction of the primary cutters 120A. The gage cutters 120B can have a different position and / or orientation on the cutter wheel 100. The differences between the cutters 120A, 120B are discussed further below. As illustrated, each mounting substrate 132 supports a plurality of the primary cutters 120 A and a plurality of the gage cutters 120B. There are nine mounting substrates 132 that together cover the full 360 degrees of the outer perimeter 112. In other constructions, there may be more or fewer than nine mounting substrates 132. The number of mounting substrates 132 can correspond directly to a number of sections of the carrier 110. For example, the carrier 110 can be of unitary construction, but may be divided into sections by a plurality of thin reliefs or gaps 136. The gaps 136 extend from the outer perimeter 112 only partially inward toward the central axis 102 (e.g., less than half the distance). In other constructions, the carrier 110 is not of unitary construction, but rather comprises a plurality of individually formed pieces secured together (e.g., wedges joined together along radially extending joints or seams).Attorney Docket No: 489825-0022 -WO01

[0026] In some constructions, including the illustrated construction, the primary' cutters 120A are provided as pointed picks. The primary cutters 120A can have a carbide material construction, which in some constructions is a tungsten carbide construction. The carbide material is formed into a protuberant or pointed shape having a central axis or direction. The carbide material forming the primary7cutter 120A may be provided as an insert coupled (e.g., press fit and / or brazed) to a tooth base 140 A. In some constructions, including the illustrated construction, the gage cutters 120B are not pointed picks but rather blunt face cutters. The gage cutters 120B have a material construction different than the primary cutters 120A. For example, the gage cutters 120B can be of a poly crystalline diamond compact (PDC) construction. The gage cutters 120B can be formed as discs or pucks. Each of the gage cutters 120B can be provided as an insert coupled (e.g., press fit and / or brazed) to a tooth base 140B. In the illustrated construction, one tooth base 140B supports two gage cutters 120B. Other constructions may utilize other arrangements or quantities. The mounting substrate 132 is provided with respective pockets for each one of the cutters 120 A, 120B. More particularly, the mounting substrate 132 includes respective pockets that at least partially receive the tooth bases 140A, 140B respectively, while at least a majority7of the cutter 120A, 120B is positioned outside the pocket to interact with the surface being trenched.

[0027] The carrier 110, the mounting substrate 132, and the tooth bases 140A, 140B are non-cutting portions of the wheel 100 and any / all of these can have yet another material construction (e.g., a softer and / or less wear-resistant material) different than those of the cutters 120A, 120B. In some constructions, the material(s) for the non-cutting portions of the wheel 100 can include 4140 steel, grade 50 steel, and 8140 steel.

[0028] The primary cutters 120A and / or the gage cutters 120B may be removably coupled to the mounting substrate 132. In some constructions, the cutters 120A and / or 120B are removably coupled to the carrier 110 by removing the entire mounting substrate 132. A new mounting substrate 132 with some or all new cutters 120 A, 120B may be coupled to the carrier 110 after removal of a used mounting substrate 132 (following substantial wear of the cutters 120A and / or 120B). In some constructions, the primary cutters 120 A have a shorter usable lifespan than the gageAttorney Docket No: 489825-0022 -WO01 cutters 120B. This can be due to the material construction and / or due to the primary cutters 120 A being configured to perform a majority of the cutting when forming the trench 37. In some cases, maintenance of the hybrid microtrencher wheel 100 can include removing and replacing a worn set of primary cutters 120A and reusing the used gage cutters 120B. For example, one or more gage cutters 120B can be separated from the used mounting substrate 132 by releasing a fastener joint (formed through the tooth base 140B) and subsequently attached to a new mounting substrate 132 by establishing a fastener joint (formed through the tooth base 140B). One exemplary threaded fastener 142 is shown in FIG. 4. The primary cutters 120A may also be removably coupled to the mounting substrate 132. Rather than a fastener joint, the tooth base 140A can be press fit into an opening in the mounting substrate 132 (from the outside, such that cutting loads do not loosen the joint). Access holes 134 in the mounting substrate 132 provide access to a rear surface of each tooth base 140A so that they may be removed (e.g., by hammering out). The primary cutters 120A and respective tooth bases 140A may be disposed after substantial wear.

[0029] As best shown in FIGS. 3 and 4, each mounting substrate 132 includes a first set of primary cutters 120A follow ed in the rotation direction 104 by a first set of gage cutters 120B. Within the same mounting substrate 132, the first sets of cutters are further followed in the rotation direction 104 by a second set of primary cutters 120A and a second set of gage cutters 120B. In the illustrated construction, each set of primary cutters 120A is a group of three. Within each set, the primary cutters 120A are all at different circumferential positions (FIG. 5). Within each set, the primary’ cutters 120 A, each of which has a pointed primary direction, are all arranged at different directions (or “attack angles”). Within each set, the forward-most or leading primary cutter 120A can have its point located and / or aimed more centrally on the hybrid microtrencher wheel 100. For example, the leading primary' cutter 120 A of a set may have its point located on a central plane 144 of the hybrid microtrencher wheel 100, while the following primary' cutters 120A of the same set have their points offset from the central plane 144. The central plane 144 is a bisector plane extending perpendicular to the axis 102. It is also noted that the arrangement of the primary cutters 120A in the first set may be the same as the arrangement of the primary’ cutters 120A of the second set on the mounting substrate 132, or theirAttorney Docket No: 489825-0022 -WO01 arrangements may be different from each other as shown in the illustrated construction.

[0030] In the illustrated construction, each set of gage cutters 120B is a group of two. Within each set, the gage cutters 120B are at the same circumferential position (i.e., side-by-side). Within each set, the gage cutters 120B, each of which has a primary direction normal to the blunt front face, are arranged in the same shared direction (i.e., the gage cutters 120B of a set are parallel). Whereas the gage cutters 120B are oriented to face generally tangential to the rotation direction 104, the primary cutters 120A are skewed with respect to the rotation direction 104. In the illustrated example, each set of primary cutters 120A includes cutters that point at least partially out sideways at different splay angles. The primary cutters 120 A are splayed in both left and right directions. All the primary cutters 120A are aimed generally forward in the rotation direction 104, although they are canted or tilted radially outward with respect to a tangent direction.

[0031] As shown best in FIG. 5, the primary' cutters 120A can be more centrally located than the gage cutters 120B. The primary' cutters 120A may be arranged in an inner row. For example, the primary’ cutters 120A may. at least in part, occupy the central plane 144 of the hybrid microtrencher wheel 100, while the gage cutters 120B do not occupy the central plane 144. The primary’ cutters 120A may define an overall swept width or thickness W1 that is less than an overall swept width or thickness W2 of the gage cutters 120B. The swept widths W1 and / or W2 can refer to the width defined by all of the respective primary cutters 120A (e.g., forming the inner row) or all of the respective gage cutters 120B (e.g., forming outer rows), respectively. In some constructions, including the illustrated construction, the first (leading) set of primary' cutters 120A has a different (e.g., smaller) swept width or thickness than the second (trailing) set of primary’ cutters 120A. In particular, the first set of primary cutters 120A may be entirely within the span S defined between the lateral or axial end surfaces 148 of the mounting substrate 132, while at least some of the second set of primary cutters 120B extends out beyond this span S. The gage cutters 120B, in some cases all the gage cutters 120B, may extend laterally outside the swept width W1 of the primary cutters 120A on both sides (along the axis 102). The gage cuttersAtorney Docket No: 489825-0022 -WO01120B, in some cases all the gage cuters 120B, may be positioned partially outside the span S of the mounting substrate 132.

[0032] The overall swept width W2 of the gage cuters 120B, which defines the gage width of the hybrid micro trencher wheel 100, can be equal to 1.07 to 1.12 times the overall swept width W1 defined by the plurality of primary cuters 120A (i.e., W2 is 7-12 percent larger than Wl) in some constructions. Although the swept width W2 of the gage cuters 120B is substantially larger than the swept width Wl of the primary cuters 120 A, the swept diameter (2x the maximum radius measured from the axis 102) of the gage cutters 120B is not substantially larger than that of the primary cuters 120A. As shown in FIG. 6, a first radius R1 is defined by the primary cuters 120 A (either all or the tallest thereof). A second radius R2 is defined by the gage cutters 120B (either all or the tallest thereof). The swept diameter defined by the radius R2 of the gage cuters 120B does not exceed the swept diameter defined by the radius R1 of the plurality of primary cuters 120A. To the contrary, the swept diameter defined by the radius R1 of the plurality of primary cuters 120A may be the same as or slightly larger than the swept diameter defined by the radius R2 of the gage cuters 120B. In some constructions, the swept diameter defined by the radius R1 of the plurality of primary cuters 120A is equal to 1 to 1.01 times the swept diameter defined by the radius R2 of the gage cuters 120B (i.e., equal to or greater by up to 1%). In some constructions, the radius R1 of the plurality of primary cutters 120 A is about 0.04 inch larger than the radius R2 of the gage cuters 120B.

[0033] Any one or combination of features described above may characterize the difference between the two different types of cuters, that is, the primary cuters 120A and the gage cuters 120B. In practice, the primary cuters 120A and the gage cuters 120B perform predominantly different functions in cuting the trench 37.

[0034] The configuration of the hybrid microtrencher wheel 100 provides for the gage cuters 120B to be responsible for holding gage of the trench 37, which means the ability- to maintain the full gage cutting width over the length of the trench 37. This is a measure of a microtrencher wheel’s durability. In addition, the gage cuters 120B are responsible for the shape and condition of the two opposed side walls of the trench 37, the botom surface of the trench 37, and the comers or edges where the trench side walls meet the botom surface. Although ground conditions will influenceAttorney Docket No: 489825-0022 -WO01 the final configuration of the trench 37, the gage cutters 120B help ensure that the trench 37 is consistently formed, holds gage, and has clean comers relatively devoid of loose material. Gage holding ability is particularly vital in applications where the product going into the trench 37 is relatively small in diameter (e.g., !4 inch to 3 inches, or more particularly 1 inch to 2 inches). In addition to making product installation easier, quicker, and thus more cost efficient, good trench quality and integrity leads to more efficient and high-quality reinstatement, which refers to the back filling of the trench 37 after the product is installed. Reinstatement can include the application of a flowable concrete into the trench 37, on top of the installed product.

[0035] FIGS. 7-9 illustrate another hybrid microtrencher wheel 200. The hybrid microtrencher wheel 200 of FIGS. 7-9 is similar in most ways to the wheel 100 of FIGS. 2-6. Reference to these figures and the preceding description is made, as the description below is focused on features of FIGS. 7-9 that differentiate from the microtrencher wheel 100 of FIGS. 2-6.

[0036] The hybrid microtrencher wheel 200 includes a carrier 110, which can be the same as that of the hybrid microtrencher wheel 100 or a variation thereof.Primary cutters 120A and gage cutters 120B are coupled to the outer perimeter 112 of the carrier 110, indirectly via arcuate segments or mounting substrates 232. The mounting substrates 232 can take a variety of forms, and in the illustrated construction each mounting substrate 232 is similar to the mounting substrates 132 of the preceding embodiment in that it supports first and second sets of primary cutters 120 A (e g., pointed carbide cutters) and first and second sets of gage cutters 120B (PDC cutters). Although they may vary among other contemplated constructions, the quantities and arrangements of the various sets of cutters 120A, 120B can be similar to those of the hybrid microtrencher wheel 100. However, the mounting substrate 232 includes an integral tooth base 240B for each gage cutter 120B. The tooth bases 240B can form a monolithic portion of the mounting substrate 232 or be welded to the mounting substrate 232. The mounting substrate is secured (e.g., welded) to the outer perimeter 112 of the carrier 110. Although small pockets are provided to receive a portion of each gage cutter 120B, the mounting substrate 232 may or may not have pockets configured to receive the gage cutter tooth bases 240B. The gageAttorney Docket No: 489825-0022 -WO01 cutters 120B can be affixed to the corresponding tooth bases 240B in a nonremovable manner (e.g., brazed). Thus, there is no fastener joint for securing and removing the gage cutters 120B. The gage cutters 120B may be considered a permanent part of the segment formed by the mounting substrate 232. The primary cutters 120A can be removably coupled to the mounting substrate 232 via the respective tooth bases 140A, similar to the preceding embodiment. An additional feature differentiating the hybrid microtrencher wheel 200 from the preceding embodiment is the additional circumferential gap or spacing in front of each set of gage cutters 120B.

[0037] FIGS. 10-12 illustrate yet another hybrid microtrencher wheel 300. The hybrid microtrencher wheel 300 of FIGS. 10-12 is similar in most ways to the wheels 100, 200 of FIGS. 2-6 and FIGS. 7-9, respectively. Reference to these figures and the preceding description is made, as the description below is focused on features of FIGS. 10-12 that differentiate from the microtrencher wheels 100, 200 of FIGS. 2-6 and FIGS. 7-9.

[0038] The hybrid microtrencher wheel 300 is characterized by a carrier 310 that supports the primary cutters 120A and the gage cutters 120B, without an intermediate mounting substrate like the substrates 132, 232. Rather, in the hybrid microtrencher wheel 300, the carrier 310 (which extends a full 360-degrees and extends from the central axis out to the outer perimeter 312) is the mounting substrate for the cutters 120A, 120B. Further, the gage cutters 120B are (e.g., individually) received directly into pockets formed at the side edges of the outer perimeter 312. There are no separate or protruding tooth bases for the gage cutters 120B. The pockets for the gage cutters 120B are deeper than the preceding constructions. As such, in a radial direction, only a minority' of each gage cutter 120B is exposed in the rotation direction, whereas a majority of each gage cutter 120B is exposed in the preceding constructions. Each gage cutter 120B is exposed in the rotation direction about the same amount radially as axially beyond the lateral or axial end surfaces 342 of the carrier 310. In the illustrated construction, the carrier 310 is the mounting substrate for each and every one of the primary cutters 120 A and each and every one of the gage cutters 120B. As such, the outer perimeter 312 is provided with respective pockets for each one of the cutters 120 A, 120B. The carrier 310 (and the hybridAttorney Docket No: 489825-0022 -WO01 microtrencher wheel 300 as a whole) is not segmented or subdivided into circumferential portions. In the illustrated construction, there are no reliefs or gaps like the gaps 136 of the preceding constructions. Rather, the carrier 310 has a solid, continuous form around the entire outer perimeter 312.

[0039] Although the quantity and arrangement of the cutters 120 A, 120B varies from that of the wheels 100, 200, the primary cutters 120 A are located more centrally than the gage cutters 120B, among other commonalities. However, each of the gage cutters 120B is individually located at a unique circumferential location - rather than being paired as shown in FIGS. 2-9. Also, there are only zero or one primary cutter 120 A located circumferentially between adjacent gage cutters 120B. As shown in FIG. 11, the primary cutters 120A may be exclusively located on the central plane 144. A majority or all of the primary cutters 120A may be centered with respect to the central plane 144 (i.e., not splayed outward). Only a minority portion of each gage cutter 120B extends out beyond the outer perimeter 312. as a majority portion of each gage cutter 120B is nested below the outer perimeter 312.

[0040] The overall swept width W2 of the gage cutters 120B, which defines the gage width of the hybrid microtrencher wheel 300, is between 2x and 3x the overall swept width W1 defined by the plurality of primary cutters 120A (i.e., W2 is 100-200 percent larger than Wl) in some constructions. Although the swept width W2 of the gage cutters 120B is substantially larger than the swept width Wl of the primary cutters 120A, the swept diameter (2x the maximum radius measured from the axis 102) of the gage cutters 120B is not substantially larger than that of the primary cutters 120 A. In fact, the swept diameter of the gage cutters 120B is equal to or smaller than the swept diameter of the primary cutters 120 A. In some constructions, the swept diameter defined by the plurality of primary cutters 120A is substantially larger than that of the gage cutters 120B. The relationship between the respective swept diameters defined by the plurality of primary cutters 120 A and the plurality of gage cutters 120B may conform to any of the relationships described above for the preceding embodiment(s), although not limited thereto.

[0041] As already noted, the particular configuration of the various cutters on the hybrid microtrencher wheel may vary beyond those exact embodiments shown and described herein. The cutters may vary7in quantity, spacing, position, angle of attack,Attorney Docket No: 489825-0022 -WOOl size and so forth without departing from the scope of certain aspects of the disclosure, such as those noted in the following claims. In some cases, aspects of known microtrencher wheels may be incorporated in a hybrid microtrencher wheel according to the present disclosure. One such example is U.S. Patent 10,124,509 of Vermeer Manufacturing, the entire contents of which is incorporated herein by reference. Also, without departing from the scope of certain aspects of the disclosure, such as those noted in the following claims, previously unknown types of cutters and / or cutter arrangements may be used in the construction of a hybrid microtrencher wheel.

[0042] Changes may be made in the above methods and systems without departing from the scope hereof. Also, aspects of various embodiments may be combined unless expressly prohibited. It should thus be noted that the matter contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense. The following claims are intended to cover all generic and specific features described herein, as well as all statements of the scope of the present method and system, which, as a matter of language, might be said to fall therebetween.

Claims

Attorney Docket No: 489825-0022 -WOOlCLAIMSWhat is claimed is:1 . A hybrid microtrencher wheel comprising: a disc-shaped carrier defining a central rotation axis and an outer perimeter; a pl urality of primary cutters secured to the outer perimeter of the disc-shaped carrier; and a plurality of gage cutters secured to the outer perimeter of the disc-shaped carrier, wherein the plurality of primary cutters have a first material construction different than a second material construction of the plurality of gage cutters, wherein the plurality of primary cutters are arranged in an inner row that defines an overall width less than a gage width of the hybrid microtrencher wheel, wherein the plurality of gage cutters define an overall width equal to the gage width of the hybrid microtrencher wheel, and wherein a swept diameter defined by rotation of the plurality of gage cutters about the central rotation axis does not exceed a swept diameter defined by rotation of the plurality of primary cutters.

2. The hybrid microtrencher wheel of claim 1, wherein the plurality of primary cutters and the plurality of gage cutters are secured to the outer perimeter of the discshaped carrier via a plurality of segments individually secured to the outer perimeter of the disc-shaped carrier.

3. The hybrid microtrencher wheel of claim 2, wherein the plurality of primary cutters includes a first set of primary cutters leading a first set of the plurality of gage cutters in a forward rotation direction, and the plurality of primary' cutters includes a second set of primary' cutters between the first set of the plurality of gage cutters and a second set of the plurality of gage cutters.

4. The hybrid microtrencher yvheel of claim 1, yvherein the first material construction of the plurality of primary cutters is a carbide material construction, and the second material construction of the plurality of gage cutters is a poly crystalline diamond compact (PDC) construction.Attorney Docket No: 489825-0022 -WOOl5. The hybrid micro trencher wheel of claim 4, wherein each one of the plurality of gage cutters includes two axially spaced PDC discs brazed to a gage cutter base.

6. The hybrid microtrencher wheel of claim 4, wherein each one of the plurality of gage cutters includes a single PDC disc brazed to the outer perimeter of the discshaped carrier.

7. The hybrid microtrencher wheel of claim 4, wherein the carbide material construction is tungsten carbide.

8. The hybrid microtrencher wheel of claim 1, wherein the plurality of gage cutters are the only components of the hybrid microtrencher wheel that extend out to the gage width.

9. The hybrid microtrencher wheel of claim 1, wherein each of the plurality of primary cutters has a protuberant shape defining a central axis that is canted in a forward rotation direction and splayed outward from a central plane that bisects the disc-shaped carrier perpendicular to the central rotation axis.

10. The hybrid microtrencher wheel of claim 1, wherein each of the plurality of gage cutters has a blunt front face arranged substantially in a forward rotation direction of the hybrid microtrencher wheel.

11. The hybrid micro trencher wheel of claim 1, wherein the plurality of primary cutters are provided in a greater quantity than the plurality of gage cutters.

12. A method of operating a microtrencher, including the hybrid microtrencher wheel of any preceding claim, to form a trench in a road surface.Attorney Docket No: 489825-0022 -WOOl13. A hybrid microtrencher wheel comprising: a disc-shaped carrier defining a central rotation axis and an outer perimeter; a plurality of primary' cutters secured to the outer perimeter of the disc-shaped carrier; and a plurality' of gage cutters secured to the outer perimeter of the disc-shaped carrier to define a gage width of the hybrid microtrencher wheel, wherein the plurality of primary cutters have a first material construction different than a second material construction of the plurality of gage cutters, wherein the gage width is 7-12 percent larger than an overall width defined by the plurality' of primary' cutters, and wherein a swept diameter defined by rotation of the plurality of primary’ cutters about the central rotation axis is equal to 1 to 1.01 times a swept diameter defined by rotation of the plurality7of gage cutters.

14. The hybrid micro trencher wheel of claim 13, wherein the plurality’ of primary cutters and the plurality of gage cutters are secured to the outer perimeter of the discshaped carrier via a plurality' of segments individually' secured to the outer perimeter of the disc-shaped carrier.

15. The hybrid microtrencher wheel of claim 14, wherein the plurality of primary cutters includes a first set of primary' cutters leading a first set of the plurality of gage cutters in a forward rotation direction, and the plurality' of primary' cutters includes a second set of primary7cutters between the first set of the plurality of gage cutters and a second set of the plurality of gage cutters.

16. The hybrid microtrencher wheel of claim 13, wherein the first material construction of the plurality7of primary7cutters is a carbide material construction, and the second material construction of the plurality of gage cutters is a poly crystalline diamond compact (PDC) construction.

17. The hybrid microtrencher wheel of claim 16, wherein each one of the plurality' of gage cutters includes two axially spaced PDC discs brazed to a gage cutter base.Attorney Docket No: 489825-0022 -WOOl18. The hybrid microtrencher wheel of claim 16, wherein each one of the plurality of gage cutters includes a single PDC disc brazed to the outer perimeter of the discshaped carrier.

19. The hybrid micro trencher wheel of claim 13, wherein each of the plurality of primary cutters has a protuberant shape defining a central axis that is canted in a forward rotation direction and splayed outward from a central plane that bisects the disc-shaped carrier perpendicular to the central rotation axis.

20. The hybrid micro trencher wheel of claim 13, wherein each of the plurality of gage cutters has a blunt front face arranged substantially in a forward rotation direction of the hybrid microtrencher wheel.

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