VACUUM EXCAVATION SYSTEM AND METHOD FOR PREVENTING BLOCKAGES FROM FORMING THEREIN

Abstract

Systems and methods for a vacuum excavator to prevent to formation of blockages know as spoil bridges are provided. The vacuum excavator includes a high vacuum blower that is coupled through a multi-stage airflow system that has a debris tank to which an excavation hose is coupled. A knuckle boom having two arm segments includes actuators to angularly position the arm segments, and hose roller assemblies that carry the excavation hose. The systems and methods control the angular position of the arm segments to control the flow curvature of the excavation hose from an excavation site to the debris tank in order to eliminate or reduce the occurrences of spoil bridges therein.

Claims

1. A vacuum excavator, comprising: a high vacuum blower coupled through a multi-stage airflow system having a debris tank to which an excavation hose is coupled; and a knuckle boom having a first arm segment carrying a first hose roller assembly and a second arm segment carrying a second hose roller assembly, a first angular position relative to horizontal of the first arm segment being controlled by a first actuator and a second angular position relative to the first arm segment being controlled by a second actuator; and wherein the excavation hose is carried by at least one of the first hose roller assembly and the second hose roller assembly; and wherein at least one of the first arm segment and the second arm segment are angularly positioned by at least one of the first actuator and the second actuator to control a flow curvature of the excavation hose from an excavation site to the debris tank.

2. The vacuum excavator of claim 1, wherein the high vacuum blower provides a suction pressure of 27 inHg.

3. The vacuum excavator of claim 1, wherein the first actuator controls the first angular position of the first arm segment between approximately 35° above and approximately 35° below horizontal.

4. The vacuum excavator of claim 1, wherein the second actuator controls the second angular position of the second arm segment between 0° and approximately 100° relative to the first arm segment.

5. The vacuum excavator of claim 1, wherein the first hose roller assembly includes two sets of rollers spaced along the first arm segment, each of the two sets of rollers including two hose contact rollers positioned at an angle relative to one another to support the excavation hose on either side of at least the bottom half of the circumference of the excavation hose.

6. The vacuum excavator of claim 5, wherein the two sets of rollers are spaced along the first arm segment by at least two feet to control a bend radius of the excavation hose therebetween.

7. The vacuum excavator of claim 5, wherein at least one of the two sets of rollers of the first hose roller assembly includes a third roller positioned horizontally above the two rollers.

8. The vacuum excavator of claim 5, wherein the two sets of rollers are joined by a support member at the apex of the two rollers of each of the two sets of rollers.

9. The vacuum excavator of claim 1, wherein the second hose roller assembly includes two sets of rollers spaced along the second arm segment, each of the two sets of rollers including two hose contact rollers positioned at an angle relative to one another to support the excavation hose on either side of at least the bottom half of the circumference of the excavation hose.

10. The vacuum excavator of claim 9, wherein the two sets of rollers are spaced along the second arm segment by at least two feet to control a bend radius of the excavation hose therebetween.

11. The vacuum excavator of claim 9, wherein at least one of the two sets of rollers of the second hose roller assembly includes a third roller positioned horizontally above the two rollers.

12. The vacuum excavator of claim 9, wherein the two sets of rollers are joined by a support member at the apex of the two rollers of each of the two sets of rollers.

13. The vacuum excavator of claim 1, wherein the knuckle boom is horizontally rotatable by approximately 180°.

14. The vacuum excavator of claim 1, wherein the first roller assembly of the first arm segment is positioned approximately 4 feet from the debris tank to which the excavation hose is coupled.

15. The vacuum excavator of claim 1, further comprising a high pressure air compressor for providing compressed air to enable air excavation.

16. The vacuum excavator of claim 1, further comprising a water storage tank and high pressure water pump for providing high pressure water to enable hydro-excavation.

17. The vacuum excavator of claim 1, wherein the multi-stage airflow system further comprises at least one cyclone filter and a final filter positioned between the debris tank and the high vacuum blower.

18. A method of reducing the formation of a spoil bridge in an excavation hose of a vacuum excavator of claim 1, comprising the steps of: providing a high vacuum pressure through a debris tank to the excavation hose to extract spoils from an excavation site; controlling a flow curvature of the excavation hose from the excavation site to the debris tank to reduce flow disruptions of the spoils extracted therethrough; and wherein the step of controlling includes angularly positioning a first arm segment carrying a first hose roller assembly and a second arm segment carrying a second hose roller assembly, wherein the excavation hose is carried by at least one of the first hose roller assembly and the second hose roller assembly.

19. The method of claim 18, wherein the step of angularly positioning the first arm segment comprises the step of angularly positioning the first arm segment between approximately 35° above and approximately 35° below horizontal.

20. The method of claim 18, wherein the step of angularly positioning the second arm segment comprises the step of angularly positioning the second arm segment between 0° and approximately 100° relative to the first arm segment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:

[0028] FIG. 1 is a rear passenger side perspective view illustration of an embodiment of a vacuum excavator constructed in accordance with the teachings of the present invention;

[0029] FIG. 2 is a rear driver side perspective view illustration of the embodiment of a vacuum excavator of FIG. 1;

[0030] FIG. 3 is a rear driver side perspective view illustration of the embodiment of a vacuum excavator of FIG. 1 showing extension of the knuckle boom and guidance of the excavation hose during operation;

[0031] FIG. 4 is an enlarged perspective view illustration of the embodiment of the knuckle boom of FIG. 3; and

[0032] FIG. 5 is an airflow schematic illustration of an embodiment of a vacuum excavator constructed in accordance with the teachings of the present invention.

[0033] While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

[0034] Turning now to the drawings, there is illustrated an embodiment of the Vacuum Excavator constructed in accordance with the teachings of the present invention. However, those skilled in the art will recognize from the foregoing and following description and the illustrations to which such is directed that various embodiments beyond those specifically described are within the scope of such teachings. As such, the disclosed embodiments and operating environments should be taken by way of illustration, and not by way of limitation. Indeed, the principles and features discussed with regard to the illustrated embodiments will find benefit in both hydro excavation and air excavation systems regardless of their platform and environment utilization.

[0035] Turning now specifically to FIG. 1, there is illustrated an embodiment of a vacuum excavator 100 of the present invention. This embodiment of the vacuum excavator 100 is shown mounted on a class 6 chassis 102 that does not require a CDL to drive or operate, which is particularly useful when air excavation alone is desired. Preferably, a silencer package 104 is included to substantially reduce the noise emissions, which greatly enhances worker safety. Further, in such a platform, the debris capability of 2 yd. is typically provided, although such is not a limitation on particulars of this embodiment. In such an embodiment, the air system may provide 185 CFM at 150 psi up to 300 CFM at 250 psi to enable fast and efficient air excavation. In such embodiment the vacuum system may be for example 1,400 CFM at 16 inHg, although it may also carry a larger 3000 CFM at 18 to 27 inHg capability. An air-oil heat exchanger 152 ensures the system without overheating.

[0036] While not illustrated, other embodiments may utilize a class 7 chassis that enables operation of both hydro excavation as well as air excavation powered by the single engine of the class 7 chassis. In this embodiment, the vacuum system utilizes a 1400 CFM, 28 inHg, 3600 RPM high vacuum blower, such as the Hibon® VTB 820 XL.

[0037] Typically, the smaller platform illustrated in FIG. 1 utilizes a water capacity of 100 gallons since air is utilized as the excavation media. However, in the embodiment utilizing the class 7 chassis, the water capacity increases an additional 300 gallons so as to enable prolonged hydro-excavation without the necessity of stopping excavation in order to refill the tank. As may be seen in FIG. 2, vacuum excavator 100 includes a water tank 108 with sight glass so that the operator may be able to tell by simple observation the level of water remaining in the tank 108.

[0038] In order to provide cold-weather operation in cold weather climates, the vacuum excavator 100 also includes a temperature controlled environmental chamber 106 shown in FIG. 1 that encloses the entire water system in an insulated heated compartment. In one embodiment an 80,000 BTU heater is provided to ensure that from the moment water enters the top of the tanks until the moment it leaves the hose reel every component is heated to prevent freezing of the water.

[0039] The vacuum excavator 100 also includes an air tool circuit hose with retractable reel 110, an air hose retractable reel 112, and a water hose retractable reel 114. These reels provide the ability to utilize air tools, as well as to hydro-excavate and air excavate the worksite depending on application.

[0040] The debris tank 116, also known as a spoils tank, is accessed via the rear of the vacuum excavator 100 via the hydraulic actuators 118. The entry port 120 to the debris tank 116 is provided in the illustrated embodiment in the upper passenger side of the rear of the debris tank 116.

[0041] The vacuum excavator 100 also includes a hydraulic knuckle boom 122 that includes two hydraulic actuators 124 and 126 to control the angular displacement from horizontal of the arm segments 128, 130. The knuckle boom 122 also includes a rotational joint 132 that allows the knuckle boom 122 to be rotated to position the excavation hose (not shown) to and about the excavation site by the user. It is noted that in FIG. 1, the knuckle boom 122 is shown in its stowed position for transport with arm segment 128 positioned across and parallel to the rear of the debris tank 116 and arm segment 130 positioned vertically with hose rollers 134, 136 directed inwardly.

[0042] As shown in FIG. 2, the vacuum excavator 100 includes an air excavation system utilizing, in one embodiment, a Vanair 300 CFM, 200 psi air compressor with a large coalescer tank 138 that provides the compressed air necessary for the air excavation. This embodiment of the vacuum excavator 100 also includes a hydro excavation digging kit with, in one embodiment, a 10 GPM @ 2500 psi water pump 140 and tools for use when the hydro excavation function is utilized.

[0043] FIG. 2 also illustrates the two cyclone filters 142, 144 utilized in the material separation process to be described more fully hereinbelow. At the bottom of each of these cyclone filters are the dust box collection trays 146, 148, one for each of the cyclone filters 142, 146 respectively.

[0044] The vacuum excavator 100 also includes the airflow conduit 150 that delivers the air from the output of the cyclone filters 142, 144 to the final filter 156 before allowing the air to pass through the positive displacement blower. The heat exchanger 154 ensure that the air system operates without overheating.

[0045] Once at the excavation site as illustrated in FIG. 3, the excavation hose 158 is connected to the entry port 120 of the debris tank 116 and is deployed through the hose rollers 134, 136, 160, and 162 of the knuckle boom 122. These hose rollers 134, 136, 160, 162 are spaced along the arm segments 130, 128 so as to prevent kinks or other sharp turns in the excavation hose 158 along its path from the excavation site on the ground, which is typically generally horizontal, to the entrance at the entry port 120 of the debris tank 116, which is generally vertical. Such feature provides the smooth transition of the spoils as they are drawn through the excavation hose 158 and into the debris tank 116 so as to prevent or minimize disruptions in the flow path that can be the starting point for bridging of the spoils therein.

[0046] As may be seen more clearly in FIG. 4 to which attention is now drawn, rollers 134 and 136 are actually formed as a set of two hose contact rollers 134.sub.1, 134.sub.2 and 136.sub.1, 136.sub.2 and are included as part of a roller assembly. Similarly, rollers 160, 162 are actually formed as a set of two hose contact rollers 160.sub.1, 160.sub.2 and 162.sub.1, 162.sub.2 and are included as part of a different roller assembly. The hose contact rollers of each set 134.sub.1, 134.sub.2 and 136.sub.1, 136.sub.2 and 160.sub.1, 160.sub.2 and 162.sub.1, 162.sub.2 are positioned at an angle relative to one another to support the excavation hose on either side of at least the bottom half of the circumference of the excavation hose 158. Preferably, the two sets of rollers of each roller assembly for each arm segment 128, 130 are separated by at least two feet to control a bend radius of the excavation hose 158 therebetween, and positioned approximately four feet from the debris tank 116 for the same purpose, although different spacing and separation may be used depending on the particular excavation hose.

[0047] As may also be seen in this FIG. 4, at least one of the two sets of rollers 134, 136, 160, 162 of each hose roller assembly includes a third hose contact roller, e.g. 136.sub.3, 162.sub.3 positioned horizontally above the two hose contact rollers 136.sub.1, 136.sub.2 and 162.sub.1, 162.sub.2, respectively. Such third hose contact roller 136.sub.3, 162.sub.3 ensures support and protection for the excavation hose 158, e.g., when the angular control of the arm segments 128, 130 results in the distal set of rollers being higher than the proximal set as shown with rollers 160, 162, respectively. In a preferred embodiment such as illustrated in this FIG. 4, both sets of rollers 134, 136, 160, 162 include such a third roller. In certain embodiments the two sets of rollers 134, 136 and 160, 162 are joined by a support member 164, 166 at the apex of the two hose contact rollers 134.sub.1, 134.sub.2 and 136.sub.1, 136.sub.2 and 160.sub.1, 160.sub.2 and 162.sub.1, 162.sub.2.

[0048] Returning to FIG. 3, it may be seen that the hydraulic actuators 124 and 126 are also utilized to aid in the smooth transition from the excavation site to the entry port 120 by limiting the positioning of arm segments 128 and 130. In one embodiment, arms segment 128 is limited in its horizontal deviation by hydraulic actuator 126 by approximately 35° above and below horizontal. Since such arm provides the connection to the vertical entry port 120 on the side of the debris tank 116, limiting the departure from horizontal of the arm segment 128 ensures that flow into the debris tank 116 is not obstructed or that the generally horizontal flow is not unduly interrupted by a bend so close to the entry port 120.

[0049] The angular displacement of arm segment 130 as controlled by the hydraulic actuator 124 can provide a more significant angular control in view of its location at the end of the knuckle boom 122 which leads to the excavation site. In one embodiment, hydraulic actuator 124 may provide up to approximately 100° of deviation of the arm segment 130 to provide the gradual transition from the excavation site to the entry port 120, and to allow stowage of the knuckle boom for transport.

[0050] As will be apparent to those skilled in the art from the foregoing, the combination of the high vacuum pressure and the gradual transition of the excavation hose 158 that leads directly into the debris tank 116 without a change in flow direction eliminates or greatly reduces the occurrence of spoil bridging. This gradual transition of the flow path as controlled by the knuckle boom 122 and its limited angular control of the arm segments 128, 130 ensures that there are no areas of obstruction or significant flow direction changes that can lessen the flow and enable the collection of spoils therein.

[0051] Indeed, this high flow and smooth transition from the excavation site to the debris tank 116 that prevents the bridging in the excavation hose 158 is also aided by the three stage airflow sections from entry of the spoils to the debris tank, through material separation and filtering, to the vacuum pump or blower, as will be described with reference now to FIG. 5.

[0052] Turning then to FIG. 5, the airflow through an embodiment of a vacuum excavator 100′ constructed in accordance with the teachings of the present invention is provided. This airflow system provides superior excavation performance while eliminating or greatly reducing the occurrence of spoilage bridge formation. The airflow system is designed to deliver smooth air movement, while providing the maximum protection for the blower.

[0053] The first stage in the airflow system is flow 164 through the excavation hose and directly into the debris tank 116 without redirection of the airflow that can cause or contribute to bridge formation. As the material in the airstream flow 164 enters the debris tank 116 it will start to drop to the bottom of the debris tank 116, and flow 166 is directed toward the front of the debris tank 116 to provide for even distribution therein. The air entering the tank along with the material is routed from the single entry point at the rear of the debris tank 116 to dual exit flows 168, 170 located at each side of the entry flow 164. In this way the air flow is slowed within the debris tank 116 and the material separation is improved.

[0054] The second stage of the airflow system takes the air from the debris tank 116 and routes it 172 into dual cyclone filters via flows 174, 176 (shown in this embodiment of the vacuum excavator 100′ on either side thereof). At this point the cyclonic action 178, 180 of these filters propels any remaining material to the sidewalls of the filters and then down into an easily maintained collection box.

[0055] In the third stage of the airflow system, the air moves from the cyclone filters via flows 182, 184 into a single final filter as shown by flows 188, 190. This washable filter will capture any fine particles, e.g. down to 10 microns in one embodiment, remaining in the air stream before allowing the air to pass through the positive displacement blower.

[0056] All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0057] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0058] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.