TRENCHER ATTACHMENT

This application is being filed on 22 April 2009, as a PCT

International Patent application in the name of Vermeer Manufacturing Company, a U.S. national corporation, applicant for the designation of all countries except the US, and Mark Cooper, Robert Daniel Hawks, and Edward Lee Cutler, all citizens of the U.S., applicants for the designation of the US only, and claims priority to U.S. Provisional patent application Serial No. 61/047,052 filed April 22, 2008, and U.S. Utility patent application Serial No. 12/426,864, filed April 20, 2009, both of which are incorporated by reference in their entirety herein.

Technical Field

The present disclosure relates to trenchers and, more particularly, to a wide boom attachment for a trencher.

Background

Trenchers capable of digging/cutting trenches have a variety of uses. For example, in construction, trenchers are often used to dig trenches for laying pipes or cables. There exist a number of different types of trenchers. One type of trencher includes a digger chain that rotates on a boom. The angle of the boom can be adjusted to control the depth of the cut. To cut the trench, the digger chain is rotated on the boom while the machine moves slowly in a direction away from the boom. The width of the chain defines the width of the trench, hi most trenchers the width of the chain is limited by the width of the boom head and chassis. There exists some disclosures in the prior art relating to systems and methods for creating a wider trench than is traditionally possible. See, for example, US 5,228,220 to Bryan, Jr. and US 5,497,567 to Gilbert. However, there remains a need to provide an improved system and method of creating wide trenches.

Summary The present disclosure provides a system and method of creating trenches of various widths, including widths that are substantially greater than the width of the boom head and chassis width. According to the trencher system of the present disclosure, the boom is designed so that it can be easily configured to create a trench

of a first width and subsequently create a trench of a second width that is different than the first width. According to an embodiment of the present disclosure a trencher is provided comprising: a chassis including a first side, second side, first end, and second end; a pair of spaced apart trencher tracks at each side of the chassis; a main boom positioned between the trencher tracks, the main boom including a first end and second end, wherein the first end of the boom is connected to the second end of the chassis; a main digger chain positioned to rotate over the boom; a first auxiliary digger chain positioned adjacent a first side of the main digger chain; a second auxiliary digger chain positioned adjacent a second side of the main digger chain; wherein the first and second auxiliary digger chains are driven by the main digger chain. According to an embodiment of the present disclosure trencher attachment is provided comprising: an auxiliary boom configured to be mounted to the mounting plate, the auxiliary boom configured to support an auxiliary digger chain; a drive axis configured to be attached to a main boom of a trencher, the drive axis including center gears for engaging a main digger chain and side gears for engaging an auxiliary digger chain; and a first mounting plate configured to be attached to interface between the main boom of a trencher and the auxiliary boom such that the auxiliary boom is aligned with the side gear for engaging the digger chain.

According to an embodiment of the present disclosure method of trenching is provided comprising: connecting a drive shaft to a distal end of a main boom; connecting an auxiliary boom to a side of the main boom such that a portion of the drive shaft extends across a portion of the auxiliary boom; connecting a main digger chain to the main boom such that the main digger chain drives the drive shaft; and connecting an auxiliary digger chain to the auxiliary boom such that the drive shaft drives the auxiliary digger chain.

Brief Description of the Figures

Figure 1 is a perspective view of a trencher according to the present disclosure;

Figure 2 is a side view of the trencher of figure 1; Figure 3 is a front view of the trencher of figure 1;

Figure 4 is a top view of an embodiment of cutting teeth and dirt drags on a chain assembly according to the present disclosure; Figure 5 is an end view of the embodiment shown in figure 4;

Figure 6 is a front view of the trencher of figure 1 with the digger chains removed to show the main boom and auxiliary booms;

Figure 7 is a top view of the trencher of figure 1 with the digger chains removed to show the main boom and auxiliary booms; Figure 8 is a top view of the main boom and auxiliary booms attached to the chassis of the trencher of figure 1;

Figure 9 is a perspective view of a distal end of the main boom with one auxiliary boom removed;

Figure 10 is a perspective view of the auxiliary boom of figure 1; Figure 11 is a perspective cross-sectional view of the auxiliary boom drive shaft;

Figure 12 is a perspective view of a portion of the auxiliary boom showing a tension system on the auxiliary boom; and

Figure 13 is a side cross-sectional view of a portion of the auxiliary boom shown in figure 12.

Detailed Description

Referring to figure 1, a trencher according to the present disclosure is described. The trencher 10 includes a chassis 12 that includes a first end 14, a second end 16, a first side 22, and a second side 24. The chassis 12 is supported on a pair of tracks 18, 20 located at each side 22, 24 of the chassis. The chassis 12 is configured to support, among other things, an operator cab 26, engine 28, hydraulic motors 30, and a conveyor system 32. In the depicted embodiments the engine 28 is used to power hydraulic motors 30 that drive the tracks 18, 20, the conveyor system 32, as well as other trencher operations (e.g., boom position and digger chain rotation).

In the depicted embodiment, a main boom 34 is attached to the second end 16 of the chassis 12. The main boom 34 includes a proximal end 36 (the end near the chassis 12) and a distal end 38 (the end far from the chassis 12). The main boom 34 supports a main digger chain 40, and at each side of the main boom 34 are auxiliary booms 42, 44 that support auxiliary digger chains 46, 48. In the depicted

embodiment, the first auxiliary digger chain 46 and the second auxiliary digger chain 48 are both driven by the drive shaft assembly 50, and the drive shaft assembly 50 is driven by the main digger chain 40. In use the main boom 34 is lowered into the ground surface while the digger chains 40, 46, 48 are typically rotating in a direction that cause the cut debris (dirt, stone, etc.) to be pulled into the trencher 10 and out via the conveyor system 32. Once the main boom 34 is lowered to the desired depth, the trencher is driven slowly in a forward direction such that the first end 14 is the front of the chassis 12 and the second end 16 is the rear of the chassis. This movement of the trencher 10 while the digger chains 40, 46, 48 are rotating creates a trench in the ground that generally matches the combined width of the digger chains 40, 46, 48.

Most prior art trenching systems do not include auxiliary booms and auxiliary digger chains. The width of the trench is typically limited by the maximum width of the main digger chain, hi turn, the maximum width of the main digger chain is typically limited by the width of the boom head and chassis. The present disclosure provides systems and methods that overcome the above-identified trench width limitations. One embodiment of the present disclosure provides a kit that can be used with an existing trencher to enable it to create much wider trenches. The kit includes auxiliary boom(s), auxiliary digger chain(s), and an associated drive shaft system. Another embodiment of the present disclosure provides digger chains with cutting elements thereon that channel the debris from the auxiliary digger chains into the path of the main digger chain to enable the main digger chain to feed the debris into the conveyor system. Another embodiment of the present disclosure provides a trencher with a main boom as well as auxiliary booms, wherein the auxiliary booms are configured to automatically funnel the debris into the path of a main digger chain so that the debris can be efficiently and effectively removed from the trench. In yet another embodiment a method of creating trenches of varying width is disclosed wherein auxiliary digger chains can be relatively quickly and easily connected to or removed from the trencher.

Referring to figures 2, 6, 8 and 10, the auxiliary booms 42, 44 are described in greater detail. In the depicted embodiment the auxiliary booms 42, 44 include proximal ends 52, 53 and distal ends 54, 55. The proximal ends 52, 53 of the

auxiliary booms 42, 44 are the ends of the booms that are closest to the chassis 12, and the distal ends 54, 55 of the auxiliary booms 42, 44 are the ends of the booms that are farthest from the chassis 12. hi the depicted embodiment the auxiliary booms 42, 44 include upper support surfaces 56, 57 and lower support surfaces 58, 59. The upper support surfaces 56, 57 are the surfaces that support the auxiliary digger chains 46, 48 as they rotate over the top of the auxiliary booms 42, 44. The portion of the digger chains that are generally viewable in use (face upward) is referred to herein as the upper cut surface of the digger chains 46, 48. Therefore, the upper support surfaces 56, 57 support the upper cut surfaces 60, 61 of the digger chains. The lower support surfaces 58, 59 are the surfaces that support the lower cut surfaces 64, 65 of the auxiliary digger chains 46, 48 as the digger chains rotate over the face of the auxiliary support booms 42, 44 that face the ground in use. The upper and lower support surfaces 56-59 are generally hidden under the digger chains 46, 48 when the digger chains are installed on the auxiliary booms 42, 44.

In the depicted embodiment the auxiliary booms 42, 44 include an idler gear 62, 63 positioned at the proximal ends 52, 53. The idler gear 62, 63 of each of the auxiliary booms 42, 44 facilitates the movement of the track around the booms, hi the depicted embodiment, the idler gear has a smaller diameter than the distance between the upper support surface 56, 57 and the lower support surface 58, 59 (i.e., the thickness or depth of the booms 42, 44). In one embodiment the idler gear 62, 63 is positioned such that the pivot axis of the idler gear is above the center line between the upper and lower support surfaces 56-59 of the auxiliary booms (figure 2). This configuration results in the lower cut surface 64 (figure 1) gradually retracting from the lower cut surface of the main digger chain 40. In the depicted embodiment the proximal ends 52, 53 of the lower support surface 58, 59 are curved such that the auxiliary digger chains 46, 48 gradually pull away from the plane of the lower cut surface of the main digger chain 40. In the depicted embodiment the radius of curvature of the curve of the lower support surface 58, 59 of the auxiliary boom 42, 44 is greater than the thickness of the auxiliary booms 42, 44. This configuration facilitates the movement of debris cut by the auxiliary booms 42, 44 into the path of the main digger chain 40.

In one embodiment the idler gear 62, 63 is positioned such that the upper cut surfaces 60, 61 of the auxiliary digger chains 46, 48 are generally in the same plane

(i.e., parallel) to the upper cut surface 64 of the main digger chain 40. It should be appreciated that many other configurations are also possible. For example, the axis of the idler gear could be positioned so that the upper cut surface 60, 61 at the proximal ends 52, 53 of the digger chains 46, 48 extend above the upper cut surface 64 of the main digger chain 40.

In the depicted embodiment the auxiliary booms 42, 44 include a modular configuration. The auxiliary booms 42, 44 each include three main sections including a first end section that supports the idler gear 62, 63 located at the proximal end 52, 53, a second section at the distal end that is shaped to receive a portion of the drive shaft assembly 50, and a third section positioned between the first section and the second section, hi the depicted embodiment the second section includes a curved end portion that is configured to allow the upper and lower support surfaces 56-59 of the auxiliary booms 42, 44 to transition smoothly with the drive gears of the drive shaft assembly 50. In the depicted embodiment the third section can be removed and replaced with a different third section to adjust the length of the auxiliary boom 42, 44. Alternatively, additional sections can be added between the first and second section to increase the length of the boom without removing the third section. Alternative embodiments of the modular feature of the boom may be configured such that the first and second section attach directly to each other without a mid-section therebetween. It should also be appreciated that in some alternative embodiments, the auxiliary booms may not be modular, hi other words, they may be of a fixed length that is not adjustable. Referring to figures 3-5, the digger chains 40, 46, 48 are described in greater detail. In the depicted embodiment the digger chains are shown as a series of linked together plates 100 with cutting elements 102 and dirt drags 104 attached thereto. The configuration and arrangement of the cutting elements facilitate the transport of the debris from the path of the auxiliary digger chains 46, 48 into the path of the main digger chain 40. hi the depicted embodiment the cutting teeth 102 are configured and arranged on the auxiliary digger chains 46, 48 in a pattern that directs the debris cut by the auxiliary digger chains 46, 48 into the path of the main digger chain 40. Figure 4 illustrates an embodiment of a pattern of teeth 102 and dirt drags 104 that direct cut debris into the path of the main digger chain 40. The dirt drags 104 are

angle towards the main digger chain. Some of the dirt drags include a bent therein that that further funnels the debris towards the main digger chain, others are straight. The main digger chain 40 includes two rows of teeth that come together at the center of the digger chain. Between the teeth are larger dirt drags 106 that pull debris into the inlet of the conveyor system 32. In the depicted orientation the teeth in the two rows come together at the proximal end 36 of the boom 34 and are spread apart at the distal end 38 of the boom 34. Referring to figures 5, the teeth are arranged so that they are spaced apart along the cut surface of the digger chains. In the depicted embodiment, the spacing between the tips of adjacent teeth is between 1 to 2 inches. The spacing between the teeth on any one plate may be much greater (e.g., 10 inches).

Referring to figures 6-9 and 11, the drive shaft arrangement 50 is described in greater detail. In the depicted embodiment, the drive shaft arrangement 50 includes a bearing assembly 70 that is configured to attach to the distal end 38 of the main boom 34 and rotatably support a cylindrical shaft 72. The cylindrical shaft includes a center portion and two opposed end portions. A driving gear assembly 74 is fixedly mounted to the center portion of the cylindrical shaft 72, and driven gears 76, 78 are fixedly mounted to the end portions of the shaft. The driving gear assembly 74 is configured to engage the main digger chain 40 and transmit force to the auxiliary digger chains 46, 48 which are configured to engage the driven gears 76, 78. In the depicted embodiment the driving gear assembly includes two ring gears connected to a spacer arrangement, and each driven gear includes a ring gear attached to a spacer. In the depicted embodiment the ring gears include the same diameter and number of teeth. It should be appreciated that in alternative embodiments, the bearing assembly 70 can include a different configuration. In the depicted embodiment the space between the driven gear 76, 78 can be adjusted via spacer that enable the driven gears to either be mounted closer together or further apart. The driven gears are mounted further apart when the auxiliary booms are spaced away from the main boom.

Referring to figures 9 and 10, the system and method for attaching the auxiliary booms 42, 44 to the main boom 34 is described in greater detail. In the depicted embodiment the system includes mounting plates 80 that are attached to the side of the main boom 34. The mounting plates are configured to be aligned and

engaged with structural features connected to the auxiliary booms 42, 44 (e.g., post, bolts, pins, apertures). In the depicted embodiment plates 80 are configured so that the spaces between the main boom 34 and auxiliary booms 42, 44 are adjustable. Spacing the auxiliary booms 42, 44 further from the main boom 34 enables wider digger chains to be mounted to the auxiliary booms 42, 44 or enable the same width digger chains to cooperatively dig a wider trench with larger spaces between the chains. The plates 80 can be attached to the auxiliary booms via bolts which are received in apertures on the plates 80. The depicted embodiment includes two mounting plates 80 that engagement plates 82-85 on the auxiliary booms 42, 44. hi the depicted embodiment, the mounting plates 80 include a pair of horizontally arranged shear stops that slidably engage a match set of shear stops on engagement plates 82-85. It should be appreciated that many other configurations are also possible. The method of connecting the auxiliary booms includes the step of aligning structural features of the side boom (auxiliary booms) with structural features of the main boom; for example, aligning posts on the auxiliary booms 42, 44 with the apertures on the mounting plates 80 of the main boom 34.

Referring to figures 12 and 13, the system and method for connecting the auxiliary digger chains 46, 48 to the auxiliary booms 42, 44 is described. In the depicted embodiment the digger chains 46, 48 are positioned around the auxiliary boom 42, 44 such that they engage the driven gear 76, 78 and the idler gear 62, 63. The idler gear 62, 63 is configured to be adjusted to apply tension to the digger chains 46, 48. In the depicted embodiment the idler gear 62, 63 is mounted to the auxiliary boom via a tension mechanism 90 that allows the idler gear 62, 63 to take up slack in the digger chains 46, 48. The idler gear is connected to a mounting arm 92. The connecting arm 92 is fixed in the vertical direction relative to the auxiliary booms 42, 44, but free to slide in the horizontal direction (direction parallel to the length of the booms). A cylinder 94 (e.g., a hydraulic cylinder) or spring is positioned and configured to normally bias the connecting arm 92 in the proximal direction (i.e., in an outward direction towards the chassis 12). In the depicted embodiment one end of the cylinder 94 engages the connecting arm, and the other end of the cylinder engages a stop block mechanism 96. hi the depicted embodiment the cylinder and stop block mechanism are used to apply tension to the chain while the bolts 98 are tightened. In some embodiment, the pressure in the

cylinder is released after the bolts 98 are tightened. It should be appreciated that many other alternative tension mechanisms are also possible. The above specification, examples, and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.