Apparatus and method for installing underground utility piping

Abstract

In a method for installing underground piping, a pipe installation apparatus is temporarily positioned at one end of a pipe trench, in which bedding sand has been placed. The apparatus has a pipe opening through which pipe can pass, and a plurality of rubber-tired pipe wheels arrayed around and biased radially inward toward the pipe opening. At least one wheel is a motor-operated drive wheel. A section of pipe introduced into the pipe opening will be tractively engaged by the drive wheels and pushed through the pipe opening and into the trends The drive motors are disengaged as required for connection of additional pipe sections, or for placing temporary spacers in the pipeline to facilitate subsequent installation of required pipeline fittings. The leading end of the pipeline engages a sled which rides over and levels die bedding sand while preventing the pipe from digging into the sand. The need for workers to enter the pipe trench is thus reduced or eliminated, making it possible to safely install piping in steep-walled trenches.

1 . An apparatus structure installing piping in a trench, said apparatus comprising:
 (a) a base structure having a front end, a rear end, and a longitudinal axis;   (b) a bulkhead attached to the base structure at a medial point between the front and rear ends of the base structure, said bulkhead being transverse to said longitudinal axis and having a pipe opening; and   (c) a pipe drive mechanism mounted in association with the bulkhead;   
     wherein said pipe drive mechanism comprises a plurality of wheels spaced around the pipe opening with their rotational axes generally transverse to the base structure's longitudinal axis, said wheels being engageable with a pipe extending through the pipe opening, with at least one of said wheels being a motor-driven wheel for applying a tractive force urging the pipe through the pipe opening. 
   
   
       2 . The apparatus of  claim 1  wherein the plurality of wheels comprises three or more wheels mounted to the bulkhead and arranged in a radial pattern around the pipe opening. 
   
   
       3 . The apparatus of  claim 1  wherein:
 (a) the plurality of wheels comprises three pairs of wheels, each pair of wheels being spaced apart in coplanar relation, and rotatably mounted to a wheel-support beam, extending between the bulkhead and a support member associated with the base structure; and   (b) one or more pairs of wheels are motor-driven wheels.   
   
   
       4 . The apparatus of  claim 3  wherein each pair of motor-driven wheels is driven by a single motor by means of a drive chain disposed around sprockets mounted to the motor and the motor-driven wheels. 
   
   
       5 . The apparatus of  claim 3  wherein each pair of motor-driven wheels is driven by a single motor, by means of a drive belt disposed around pulleys mounted to the motor and the motor-driven wheels. 
   
   
       6 . The apparatus of  claim 3  wherein the three pairs of wheels are arranged in a radial pattern around the pipe opening. 
   
   
       7 . The apparatus of  claim 1 , further comprising biasing means for biasing one or more of the wheels radially inward toward the pipe opening. 
   
   
       8 . The apparatus of  claim 1 , further comprising anchorage means. 
   
   
       9 . The apparatus of  claim 8  wherein the anchorage means comprises a pair of outriggers pivotably mounted to the base structure, each outrigger having an anchorage member adapted to penetrate a soil mass. 
   
   
       10 . The apparatus of  claim 1 , further comprising means for adjusting the position of at least one of the wheels relative to the pipe opening. 
   
   
       11 . The apparatus of  claim 1  wherein each motor-driven wheel is driven by a hydraulic motor, and further comprising:
 (a) a power module comprising a hydraulic pump, a hydraulic fluid reservoir, and an engine for driving the hydraulic pump;   (b) a control module for controlling the flow of hydraulic fluid between the fluid reservoir and the one or more hydraulic motors.   
   
   
       12 . A method for installing an underground pipeline, said method comprising the steps of:
 (a) excavating an elongate trench;   (b) excavating a working zone at a selected location along the length of the trench;   (c) providing a pipe installation apparatus comprising:
 c.1 a base structure having a front end, a rear end, and a longitudinal axis: 
 c.2 a bulkhead attached to the base structure at a medial point between the front and rear ends of the base structure, said bulkhead being transverse to said longitudinal axis and having a pipe opening; and 
 c.3 a pipe drive mechanism mounted in association with, the bulkhead; 
 wherein said pipe drive mechanism comprises a plurality of wheels spaced around the pipe opening with their rotational axes generally transverse to the base structure's longitudinal axis, said wheels being engageable with a pipe extending through the pipe opening, with at least one of said wheels being a motor-driven wheel for applying a tractive force urging the pipe through the pipe opening; 
   (d) positioning the pipe installation apparatus within tire working zone such that:
 d.1 the longitudinal axis of the apparatus is in substantial alignment with the trench; and 
 d.2 the pipe opening is at a selected elevation higher than the bottom of the trench; 
   (e) feeding the lead end of a first pipe section through the pipe opening so as to engage the pipe drive mechanism, such that the lead end of the first pipe section is advanced into the trench;   (f) temporarily disengaging the pipe drive mechanism after the first pipe section has been advanced a selected distance;   (g) coupling the lead end of a second pipe section to the trailing end of the first pipe section, forming a pipe string;   (h) activating the pipe drive mechanism to advance the pipe string further into the trench; and   (i) coupling additional pipe sections to the pipe string and incrementally advancing the pipe string into the trench after each pipe section addition, until the pipe string of desired length has been advanced into the trench.   
   
   
       13 . The method of  claim 12  comprising the further step of excavating a secondary channel along the length of the trench, for receiving the pipe string. 
   
   
       14 . The method of  claim 12  further comprising the steps of;
 (a) installing granular bedding material in the trench prior to the first pipe section being advanced into the trench; and   (b) engaging the lead end of the first pipe section with a pipe sled comprising a sole plate with an upturned prow member;   
     such that as the pipe string is advanced into the trench with the pipe sled bearing on the granular material, the pipe sled also advances into the trench while smoothing die granular material beneath it. 
   
   
       15 . The method of  claim 12  comprising the further step of installing spacer means at one or more positions along the length of the pipe string. 
   
   
       16 . The method of  claim 12  comprising the further steps of:
 (a) placing backfill material in the trench, to cover the installed pipeline; and   (b) compacting the backfill material using a packer comprising:
 b.1 front and rear sections each having a roller drum; 
 b.2 an articulation linkage coupling the front and rear sections, said linkage being swivelable about a vertical axis; 
 b.3 packer drive/braking means associated with a selected roller drum; 
 b.4 steering means; and 
 b.5 remote control means for controlling the drive/braking means and steering means. 
   
   
   
       17 . A packer for compacting backfill materials, said packer comprising:
 (a) front and rear sections each having a roller drum;   (b) an articulation linkage coupling the front and rear sections, said linkage being swivelable about a vertical axis;   (c) packer drive/braking means associated with a selected roller drum;   (d) steering means; and   (e) remote control means for controlling the drive/braking means and steering means.   
   
   
       18 . The packer of  claim 17  wherein the packer drive/braking means and steering means are hydraulically actuated. 
   
   
       19 . The packer of  claim 17  wherein the remote control means comprises a radio-controlled wireless system. 
   
   
       20 . The packer of  claim 17 , further comprising a hydraulically-actuated dozer blade associated with a selected one of the roller drums.