CA2631480A1

CA2631480A1 - Boom assembly suitable for pipelaying

Info

Publication number: CA2631480A1
Application number: CA 2631480
Authority: CA
Inventors: M. Patrick Mcnamara
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-05-08
Filing date: 2008-05-08
Publication date: 2009-11-08

Abstract

A boom assembly suitable for mounting on a conventional tracked excavator for use in pipelaying and a pipelayer so constituted. The boom assembly including: a boom having at its proximal end means for pivotally mounting the boom to an excavator platform and at its distal end sheave sheave suitable for accommodating a load line; a power winch mounted on the boom, oriented for winching a load line running to the end sheave and connectable to the excavator's hydraulic system when the boom assembly is installed; and means for, when the boom assembly is installed, pivoting the boom relative to the platform using the excavator's hydraulic system.

Description

BOOM ASSEMBLY SUITABLE FOR PIPELAYING
FIELD OF THE INVENTION

[01] The present invention relates to a boom assembly suitable for mounting on a conventional tracked excavator for use in pipelaying and a pipelayer so constituted.

BACKGROUND OF THE INVENTION

[02] The construction of pipelines typically requires specialized equipment suitable for moving both individual short sections of pipe and long sections of pipe (typically comprising short sections joined together). In the case of underground pipelines, such long sections of pipe are usually assembled (typically by welding) adjacent the trench in which the pipe is intended to be buried. After a suitable long section of pipe has been assembled, it is raised, moved over the trench and lowered into the trench.

[03] Many different implements for handling sections of pipe in pipeline construction are known. The most-widely used implement for pipeline pipe handling is a dedicated track-type tractor pipelayer, often referred to as a sideboom, having an A-frame-type boom pivotally mounted on a side of the tractor (typically between the upper and lower portions of the track on that side) with a load line and means for raising and lowering the boom (typically, either a hydraulic cylinder or cylinders, or a cable running between a spool, typically on the side of the tractor opposite the boom, and the vicinity of the distal end of the boom).

[04] US Patent No. 6,893,189 (Matsuchita et al., issued 17 May 2005) discloses a pipelayer comprising a track-mounted undercarriage, a superstructure mounted on the undercarriage so as to be rotatable with respect to the undercarriage, a boom pivotally mounted to the superstructure, a hydraulic ram for pivoting the boom relative to the superstructure, a reel mounted on the opposite side of the superstructure from the boom and a load line running from the reel to a load hook via sheaves in the vicinity of the boom mounting and the distal end of the boom.

[05] Excavators are commonly used in heavy construction including pipeline construction. An excavator consists of an undercarriage with tracks or wheels, a platform rotatably mounted on the undercarriage, an articulated arm comprising a boom pivotally mounted to the platform and another longitudinal member, commonly referred to as a stick, pivotally mounted to the distal end of the boom, a bucket pivotally mounted to the distal end of the stick, an operator's cab on the platform typically beside the boom-mount location, an engine mounted on the platform, typically opposite the boom-mount location so as to provide a counterweight to the articulating arm (additional counterweight is often included in the vicinity of the engine), a hydraulic pump driveably connected to the engine, and hydraulic cylinders hydraulically connected to the hydraulic pump and configured to permit the operator to articulate the arm and bucket.

[06] US Patent No. 4,693,384 (Gilmore, Jr., issued 15 September 1987) discloses an articulated-arm-type excavator wherein the boom has a trolley track affixed to its underside. A trolley member from which a block is suspended travels along the track and is urged into an operator-selected position by a double-acting hydraulic cylinder. A power winch is mounted on the excavator platform and a lifting cable runs from the winch over the block to a lifting hook.

[07] US Patent No. 4,666,049 (Gilmore, Jr., issued 19 May 1987) discloses an articulated-arm-type excavator having an A-frame-type boom mounted on the side of the excavator undercarriage between the upper and lower portions of the track on that side (the boom and mounting being similar to the corresponding features on a sideboom tractor), and a trolley track affixed to the underside of the excavator boom, wherein the distal end of the A-frame-type boom is connected to a trolley member that runs within the track, such that the excavator boom supports the A-frame-type boom. A power winch is mounted to the A-frame-type boom and a lifting cable runs from the winch over a block at the distal end of the A-frame-type boom to a lifting hook.

SUMMARY OF THE INVENTION

[08] In accordance with the present invention, there is provided a boom assembly for replacing the articulated arm on an excavator so as to permit the thus-modified excavator to be used conveniently for pipelaying and other tasks requiring heavy lifting, the excavator having an excavator platform on which there is a hydraulic system including an excavator hydraulic cylinder for pivoting the articulated arm relative to the excavator platform, an excavator cylinder mount for the proximal end of the excavator hydraulic cylinder, an articulated-arm mount and an operator's cab, the boom assembly consisting of: a boom with a proximal end and a distal end, having at the proximal end means for pivotally mounting the boom at the articulated-arm mount of an excavator; a power winch mounted to the boom and connectable to an excavator's hydraulic system when the boom assembly is installed; and means for, when the boom assembly is installed, pivoting the boom relative to an excavator platform using the excavator's hydraulic system.

[09] The means for pivoting the boom may include means on the boom for connecting the boom to the distal end of an excavator hydraulic cylinder. The means for pivoting the boom may include a boom cylinder having a distal end configured for connecting to the boom and a proximal end configured for connecting to an excavator cylinder mount, the boom cylinder configured for connecting to the excavator's hydraulic system.

[10] Preferably, the power winch is located sufficiently distal from the boom proximal end, such that when the boom is installed, the power winch does not intrude into the view from the cab in a direction generally parallel to the pivot axis of the boom, through the full range of motion of the boom.

[11] Preferably, the boom assembly includes a sheave in the vicinity of the boom distal end and a load line spooled on the power winch and routed over the sheave. Preferably, the boom assembly includes a compound pulley system comprising a fixed pulley attached to the boom in the vicinity of the sheave and a moveable pulley.

[12] In another aspect, there is provided a boom assembly including: a boom with a proximal end and a distal end, having at its proximal end means for pivotally mounting the boom to an excavator platform at the articulating-arm mount and having in the vicinity of the distal end an end sheave suitable for accommodating a load line; a power winch mounted on the boom, oriented for winching a load line running to the end sheave and connectable to the excavator's hydraulic system when the boom assembly is installed; and means for, when the boom assembly is installed, pivoting the boom relative to the platform using the excavator's hydraulic system.

[13] Preferably, the means for pivoting the boom relative to the platform using the excavator's hydraulic system includes a hydraulic cylinder distal end mounting means on the boom for connecting the distal end of the hydraulic cylinder or cylinders used for pivoting the excavator boom relative to the platform, or if that hydraulic cylinder, or those cylinders, are not suitable, for connecting the distal end of a selected hydraulic cylinder, or cylinders, to the boom.

[14] Preferably, the power winch is mounted in the general vicinity of the proximal end of the boom. Preferably, the power winch is mounted sufficiently distal from the boom proximal end such that, when the boom is installed, the power winch does not intrude into the view from the cab in a direction generally parallel to the pivot axis of the boom, through the full range of motion of the boom.

[15] Preferably, the boom assembly includes a load line spooled on the power winch and routed over the sheave. Preferably, the load line is connected to a load supporting device such as a conventional load hook. Preferably, the boom assembly includes a compound pulley system wherein a fixed pulley is attached to the boom in the vicinity of the distal end of the boom and a moveable pulley is attached to the load supporting device and the load line is rove through the pulleys as required.

[16] In another aspect, there is provided an apparatus for pipelaying and other tasks requiring heavy lifting, the apparatus consisting of: an undercarriage with tracks or wheels; a platform rotatably mounted on the undercarriage; an engine mounted to the platform; a hydraulic pump mounted to the platform and driveably connected to the engine; a boom with a proximal end and a distal end, pivotally mounted at the proximal end to the platform; a hydraulic cylinder connected between the boom and the platform and connected to the hydraulic pump; a power winch mounted to the boom and connected to the hydraulic pump; a sheave attached to the boom in the vicinity of the boom distal end;
and a load line extending from the power winch over the sheave.

[17] Preferably the apparatus also includes an operator's cab mounted to the platform in the vicinity of the boom, wherein the power winch is located sufficiently distal from the boom proximal end such that the power winch does not intrude into the view from the cab in a direction generally parallel to the pivot axis of the boom, through the full range of motion of the boom.

SUMMARY OF THE DRAWINGS

[18] These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to in any way limit the scope of the invention to the particular embodiment or embodiments shown, wherein:

[19] FIG. 1 is an elevation view of a boom assembly embodiment of the present invention shown installed on an excavator, the excavator shown stylized DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

[20] An exemplary boom assembly embodiment generally identified by reference numeral 10, will now be described with reference to FIG. 1. In this specification and claims, words indicating absolute directions (for example, up, down etc.) and fixed orientations (for example, front, back, upper, lower etc.) are used for convenience of description and should not be understood to mean that such directions and orientations always pertain.

[21] The boom assembly 10 is shown installed on an excavator 12, from which the articulated arm (not shown) has been removed, and supporting a pipe 14.

[22] The excavator 12 includes: an undercarriage 16 with two tracks 18, and a platform 20 rotatably mounted on the undercarriage 16. Mounted on the platform 20, there is: an operator's cab 22; an engine and hydraulic pump, jointly indicated by reference number 24; a counterweight 26; an excavator-boom mount 28; and a boom-cylinder proximal-end mount 30. The excavator 12 includes a conventional arrangement of hydraulic hoses and hydraulic controls (not shown) for powering and controlling the articulated arm.

[23] The excavator-boom mount 28 includes a structure with two spaced-apart shoulders having aligned holes and a boom pin 32 passing therethrough. The boom-cylinder proximal-end mount 30 comprises two spaced-apart projecting tabs with aligned holes and a cylinder proximal pin 34 passing therethrough.

[24] The boom assembly 10 includes a boom 36, a power winch 38 mounted on the boom 36, and a load line 40 connected to the power winch 38.

[25] The boom 36 has, at its proximal end, a pivot mount 42 having an internal boom-pin bore 44 suitable for receiving the boom pin 32. The pivot mount 42 may be configured for a particular excavator model, in that the boom-pin bore may be sized for the particular boom pin 32 and the pivot mount 42 may be sized for a desired fit between the shoulders. Alternatively, the pivot mount may be configured to accommodate a variety of excavator models, in that the pivot mount 42 may be bushed to obtain a desired fit between the shoulders and the boom pin 32 may be bushed to obtain a desired fit within the boom-pin bore 44. Further alternatively, the boom 36 may be provided with a selection of removably attachable pivot mounts, each such pivot mount configured to fit a particular model or group of models of excavators.

[26] Distal along the boom 36 from the pivot mount 42, there is a boom-cylinder distal-end mount 46 for connecting the boom 36 to a boom cylinder 48 extending between the boom-cylinder proximal-end mount 30 and the boom-cylinder distal-end mount 46. Preferably, the boom cylinder 48 is the excavator hydraulic cylinder used for pivoting the articulated arm with respect to the platform 20. However, if such excavator hydraulic cylinder is not suitable for use with the boom assembly 10 (perhaps because of inadequate range of movement) it may be replaced with a suitably configured hydraulic cylinder.
There may be more than one boom-cylinder distal-end mount 46 with each such boom-cylinder distal-end mount 46 configured to accommodate the hydraulic cyiinder of a particular model or group of models of excavators.
Alternatively, the boom 36 may be provided with a selection of removably attachable boom-cylinder distal-end mounts, each such boom-cylinder distal-end mount and the associated means for mounting same being configured to fit a particular model or group of models of excavators.

[27] The power winch 38 is mounted on the upper side of the boom 36, sufficiently distal from the pivot mount such that through the full range of pivotal motion of the boom, the power winch does not intrude into the view from the cab in a direction generally parallel to the pivot axis of the boom. In this way, when the boom assembly 10/excavator 12 combination is in its normal in-use position as shown in FIG. 1, the power winch does not impede the operator's view along the length of the pipe 14.

[28] The power winch 38 and boom cylinder 48 are powered and controlled using the hydraulic system of the excavator 12. Preferably, the hydraulic system includes such conventional quick connectors as are required to facilitate disconnecting the articulated arm and installing the boom assembly 10.

[29] The load line 40 extends from the power winch 38, over a sheave 50 at the distal end of the boom 36, into a compound pulley system comprising a fixed pulley 52 and a moveable pulley 54 and terminates at one or the other of the moveable pulley 54 or the vicinity of the fixed pulley 52 as is considered desirable by the manufacturer. Attached to the moveable pulley 54, there is a load hook 56 (with a safety clip). The pipe 14 is supported by a sling 58 having each end attached to the load hook 56.

[30] The boom assembly 10 may be installed on an excavator 12 by:
supporting the articulated arm in the desired removal position; removing the boom pin 32; disconnecting the distal end of the excavator hydraulic cylinder if it is suitable for the boom cylinder 48 or disconnecting the proximal end of the excavator hydraulic cylinder if it is not suitable for the boom cylinder 48;
disconnecting the hydraulic lines supplying the articulated arm and, if required, the excavator hydraulic cylinder; separating the excavator and articulated arm (typically by using a crane or other lifting device); bringing the excavator 12 and boom assembly 10 into alignment (again, typically by using a crane or other lifting device); inserting the boom pin 32 through the shoulders and boom-pin bore 44; connecting the excavator hydraulic cylinder to the boom-cylinder distal-end mount 46 or connecting a boom cylinder 48 already connected to the boom-cylinder distal-end mount 46 to the boom-cylinder proximal-end mount 30, as required; and connecting the hydraulic lines as required.

[31] Use of the boom assembly 10 does not require any significant modifications to the excavator 12 on which it is used. As mentioned above, it is desirable to install quick connect hydraulic fittings to facilitate installation and remove of the boom assembly 10 (and to reduce losses of hydraulic oil), but such fittings are commonplace and relatively inexpensive, and their installation would be a minor modification.

[32] In this patent document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.

[33] It will be apparent to one skilled in the art that modifications may be made to the illustrated embodiments without departing from scope of the Claims.

Claims

1. A boom assembly for replacing the articulated arm on an excavator so as to permit the thus-modified excavator to be used conveniently for pipelaying and other tasks requiring heavy lifting, the excavator having an excavator platform on which there is a hydraulic system including an excavator hydraulic cylinder for pivoting the articulated arm relative to the excavator platform, an excavator cylinder mount for the proximal end of the excavator hydraulic cylinder, an articulated-arm mount and an operator's cab, the boom assembly comprising:
a) a boom with a proximal end and a distal end, having at the proximal end means for pivotally mounting the boom at the articulated-arm mount of an excavator;
b) a power winch mounted to the boom and connectable to an excavator's hydraulic system when the boom assembly is installed;
and c) means for, when the boom assembly is installed, pivoting the boom relative to an excavator platform using the excavator's hydraulic system.

2. The boom assembly of claim 1, wherein the means for pivoting the boom comprises means on the boom for connecting the boom to the distal end of an excavator hydraulic cylinder.

3. The boom assembly of claim 1, wherein the means for pivoting the boom comprises a boom cylinder having a distal end configured for connecting to the boom and a proximal end configured for connecting to an excavator cylinder mount, the boom cylinder configured for connecting to the excavator's hydraulic system.

4. The boom assembly of any one of claims 1 to 3, wherein the power winch is located sufficiently distal from the boom proximal end, such that when the boom is installed, the power winch does not intrude into the view from the cab in a direction generally parallel to the pivot axis of the boom, through the full range of motion of the boom.

5. The boom assembly of any one of claims 1 to 4, further comprising a sheave in the vicinity of the boom distal end and a load line spooled on the power winch and routed over the sheave.

6. The boom assembly of claim 5 further comprising a compound pulley system comprising a fixed pulley attached to the boom in the vicinity of the sheave and a moveable pulley.

7. An apparatus for pipelaying and other tasks requiring heavy lifting, the apparatus comprising:
a) an undercarriage with tracks or wheels;
b) a platform rotatably mounted on the undercarriage;
c) an engine mounted to the platform;
d) a hydraulic pump mounted to the platform and driveably connected to the engine;
e) a boom with a proximal end and a distal end, pivotally mounted at the proximal end to the platform;
f) a hydraulic cylinder connected between the boom and the platform and connected to the hydraulic pump;
g) a power winch mounted to the boom and connected to the hydraulic pump;
h) a sheave attached to the boom in the vicinity of the boom distal end; and i) a load line extending from the power winch over the sheave.

8. The apparatus of claim 8, further comprising an operator's cab mounted to the platform in the vicinity of the boom, wherein the power winch is located sufficiently distal from the boom proximal end such that the power winch does not intrude into the view from the cab in a direction generally parallel to the pivot axis of the boom, through the full range of motion of the boom.