Abstract:
The method and two devices provide for the underground connection of pipe with minimal disruption of the surrounding landscape. A main pipe is cleaned by a surface preparation tool designed to access the main pipe through a small hole. An adaptor is attached to a second pipe, and then placed in a clamping device designed to access the main pipe and clamp the adaptor thereto through the small hole. Electricity is passed through the adaptor, thereby softening the plastic so that this softening and the pressure of the clamp secures the adaptor to the main pipe. The main pipe is then pierced by the adaptor&#39;s tapping tee.

Description:
CROSS-REFERNCE TO RELATED APPLICATIONS 
     This is a continuation-in-part application of U.S. application Ser. No. 09/855,222 filed May 15, 2001, which claims the benefit of priority to U.S. Provisional Application No. 60/204,289 filed May 15, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention is a method and apparatus for connecting underground pipe while minimizing disturbance to the surrounding landscape. 
     2. Description of the Related Art 
     Currently, the process of joining underground pipes requires significant excavation of the ground around the joint, thereby causing considerable disruption to the surrounding landscape, and limiting the location of underground pipes with respect to buildings. A method of joining pipes underground by using only a small hole, as is provided by the present invention, minimizes these difficulties. 
     U.S. Pat. No. 5,791,073, issued to M. G. Palmer and R. M. Saroney on Aug. 11, 1998, describes a vacuum excavation system which may be used to provide the holes in the ground through which the apparatus and method of the present invention may connect pipes. No pipe connection system is disclosed within this patent. 
     SUMMARY OF THE INVENTION 
     The invention is an apparatus and method for joining underground pipes while causing as little disturbance as possible to the surrounding landscape. 
     The process begins by using a vacuum excavator (well-known) to produce a vertical hole large enough for the boring head of a directional drilling machine (also well-known), and to provide space for an electrofusion tee (described below). Next, a hole is drilled towards the main at an acute angle from horizontal, with 15° being preferred, using the directional drilling machine, until the depth of the pipe is reached. The boring head is then angled horizontal for the remainder of its travel to the main pipe. The boring head stops within the hole made by the vacuum excavator, directly above the main pipe. 
     Once the boring head has reached the vacuum-excavated hole, an appropriate length of pipe is attached to a Chinese Finger (well-known) on the boring head, and the boring head is retracted through the hole, pulling the pipe with it. 
     Next, the main pipe must be prepared for bonding. The main pipe will typically include a layer of polyethylene oxide approximately 0.002 inch to 0.004 inch thick, which must be removed. The surface preparation tool described herein performs this oxide removal by milling the oxide from the top half of the main pipe. The pipe must then be kept free of foreign contamination. Cleaning the main pipe with denatured alcohol will serve this purpose. 
     The adaptor is then attached to the end of the pipe protruding from the ground. The adapter is clamped into an electrofusion valve-clamping tool. Electrical wires are secured to each of the two contacts in the adaptor. The clamping tool is then lowered around the main pipe, thereby positioning the adaptor on top of the main pipe. The clamping tool clamps around the bottom of the pipe to pull the adaptor against the pipe. Electrical current passing through the adaptor softens the plastic. The combination of softening the plastic and pressure seals the adaptor to the main pipe. After testing the connection by pressure testing, the main pipe can be pierced using a tapping tee contained within the adaptor. Gas can now flow between the main pipe and the new pipe. 
     It is therefore an object of the present invention to provide a method for connecting underground pipes while minimizing disturbance of the surrounding soil. 
     It is another object of the present invention to provide a method for connecting underground pipes whereby the entire process is completed through two holes in the ground. 
     It is a third object of the present invention to provide a method of connecting underground pipes that is simpler and less costly than previous methods. 
     It is a fourth object of the present invention to provide a method of connecting underground pipes that permits the pipe to be located closer to buildings than previous methods will permit. 
     It is a fifth object of the present invention to provide a surface preparation tool for underground connection of pipes capable of preparing the surface of an underground pipe through a small diameter hole. 
     It is a sixth object of the present invention to provide a surface preparation tool for underground connection of pipes having a milling cutter for removing an oxide layer from a pipe. 
     It is a seventh object of the present invention to provide a surface preparation tool capable of accessing the top 180° of an underground pipe through a small hole. 
     It is an eighth object of the present invention to provide an electrofusion valve clamping tool capable of securing an adaptor to an underground pipe through a small diameter hole in the ground. 
     It is a ninth object of the present invention to provide an electrofusion valve clamping tool having clamping ears for pulling the adaptor against the pipe. 
     These and other objects of the invention will become apparent through the following description and claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a surface preparation tool according to the present invention. 
     FIG. 2A is an exploded perspective view of the handle portion and part of the milling assembly portion of a surface preparation tool according to the present invention. 
     FIG. 2B is an exploded perspective view of the remaining portion of the milling assembly for a surface preparation tool according to the present invention. 
     FIG. 3 is a side view of a surface preparation tool according to the present invention, showing the tool in its clamped configuration. 
     FIG. 4 is a front environmental view of a surface preparation tool according to the present invention, showing the upper portion of the handle rotated 90° for clarity, and the tool placed over the top of a pipe. 
     FIG. 5 is a front environmental view of a surface preparation tool according to the present invention, showing the upper portion of the handle rotated 90° for clarity, and the tool clamped to a pipe. 
     FIG. 6 is a front environmental view of a surface preparation tool according to the present invention, showing the tool rotated to one side of a pipe. 
     FIG. 7 is a front environmental view of a surface preparation tool according to the present invention, showing the tool rotated to the opposite side of a pipe. 
     FIG. 8 is a perspective view of the surface preparation tool according to the present invention illustrating the alternate handle and clamping arm. 
     FIG. 9 is an environmental view of the surface preparation according to the present invention illustrating the alternate handle and clamping arm being lowered to an exposed corroded pipe in an excavated access hole. 
     FIG. 10 is a perspective environmental view of the surface preparation tool according to the present invention illustrating the alternate handle and clamping arm attached to an exposed corroded pipe in an excavated access hole. 
     FIG. 10A is a side environmental view of the surface preparation tool according to the present invention illustrating the alternate clamping arm attached to an exposed corroded pipe and excavated access hole. 
     FIG. 11 is a perspective environmental view of the surface preparation tool according to the present invention illustrating the alternate handle and clamping arm being removed from an exposed prepared pipe and excavated access hole. 
     FIGS. 12A-12H are front views of the milling assembly of the surface preparation tool according to the present invention illustrating the alternate clamping arm being attached to a pipe. 
     FIGS. 13A-13M are front views of the milling assembly of the surface preparation tool according to the present invention illustrating the alternate clamping arm attached to a pipe being rotated 90 degrees from center in either direction. 
     FIG. 14 is a perspective view of the clamping component of an electrofusion valve-clamping tool according to the present invention. 
     FIG. 15 is a perspective view of the bottom rear portion of an electrofusion valve clamping tool according to the present invention, illustrating the interaction between the pusher pin and clamping ear. 
     FIG. 16 is a perspective view of a handle assembly of an electrofusion valve-clamping tool according to the present invention. 
     FIG. 17A is an exploded perspective view of the handle assembly of an electrofusion valve-clamping tool according to the present invention. 
     FIG. 17B is an exploded perspective view of the lower portion of an electrofusion valve-clamping tool according to the present invention. 
     FIG. 18 is a perspective view of the clamping component of the electrofusion valve-clamping tool according to the present invention, showing the milling assembly prior to engaging the adaptor. 
     FIG. 19 is a perspective view of an adaptor that is standard in the art of connecting pipes, which the electrofusion valve-clamping tool is designed to clamp to a pipe. 
     FIG. 20 is a perspective view of the clamping component of the electrofusion valve-clamping tool according to the present invention, showing the tool securing the adaptor. 
     FIG. 21 is a perspective view of the clamping assembly of the electrofusion valve-clamping tool according to the present invention, showing the tool securing the adaptor to a pipe. 
     FIG. 22 is an end view of the clamping component of the electrofusion valve-clamping tool according to the present invention, showing the tool securing the adaptor to a pipe. 
     FIG. 23 is a perspective view of the clamping tool of the present invention illustrating the alternate handle and main body extensions. 
     FIG. 24A is an exploded view of the handle portion of the clamping tool illustrating the alternate crank handle. 
     FIG. 24B is an exploded view of the clamp portion of the clamping tool illustrating the main body extensions and attachment to the handle portion. 
     FIG. 25 is a perspective environmental view of the clamping tool illustrating the alternate handle and main body extensions attached to an exposed pipe and excavated access hole illustrating the rotation of the handle. 
     FIG. 26A is a front view of the clamp component of the clamping tool in the open position illustrating the alternate main body extensions. 
     FIG. 26B is a front view of the clamp component of the clamping tool in the open position, illustrating the alternate main body extensions, having an attached valve with electrode connected being lowered onto a prepared pipe. 
     FIG. 26C is a front view of the clamp component of the clamping tool in the open position, illustrating the alternate main body extensions, having an attached valve with electrode connected engaged with a prepared pipe. 
     FIG. 26D is a front view of the clamp component of the clamping tool in the open position, illustrating the alternate main body extensions, having an attached valve with electrode connected engaged with a prepared pipe illustrating the rotational movement of the paddles. 
     FIG. 26E is a front view of the clamp component of the clamping tool in the open position, illustrating the alternate main body extensions, having an attached valve with electrode connected engaged with a prepared pipe illustrating the paddles rotated and engaging the pipe. 
     FIG. 26F is a front view of the clamp component of the clamping tool in the open position illustrating the alternate main body extensions being removed from a repaired pipe. 
     FIG. 27 is a perspective view of the clamp component of the clamping tool illustrating the alternate main body extensions having an attached valve with electrode connected engaged with a prepared pipe. 
     FIG. 28 is a perspective view of a repaired pipe illustrating the attached valve and prepared pipe area. 
     Like reference numbers denote like elements throughout the drawings. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention is a process for connecting underground pipes with minimal disruption of the surrounding landscape. The invention includes a surface preparation tool and an electrofusion valve-clamping tool. 
     The surface preparation tool is illustrated in FIGS. 1-7. Referring to FIGS. 1-2, the surface preparation tool  10  includes a handle portion  100  and a milling assembly  200 , pivotally secured to the handle portion  100 . 
     The milling assembly  200  includes a base plate  202 . The base plate  202  includes means for rotatably securing a milling cutter, means for securing a motor, and preferably includes means for securing a gearbox. The means for rotatably securing a milling cutter are a pair of flanges  204  protruding from the front of the base plate, with each flange defining an aperture  206 . A third flange  208  protrudes from the front of base plate  202 , defining a third aperture  210  coaxial with the apertures  206 , forming the means for securing a gearbox. An aperture  212  within the base plate is located between one flange  204  and the flange  208 , providing the means for securing a motor. 
     A motor  214  is secured to the rear of the base plate  202 , with its drive shaft  216  protruding through the aperture  212 . The motor  214  may be attached to the base plate  202  by any conventional means, and the motor  214  and base plate  202  preferably include mounting holes  217  for receiving screws for this purpose. The motor  214  may be of any conventional type, with an air motor being preferred. The drive shaft  216  is operatively connected to the gears  219  within the gearbox  218 , secured to the base plate  202  opposite the motor. 
     A pipe guide assembly  220  is secured to the base plate  202 . The pipe guide assembly includes a pair of U-shaped end plates  222  at each end of the base plate  202 , a first side plate  224  extending from the tip of one end plate  222  to the corresponding tip of the other end plate  222 , and a second side plate  226  extending from the opposite tip of one end plate  222  to the corresponding tip of the other end plate  222 . The first side plate  224  includes means for pivotally securing a clamp, preferably including a clamp-securing flange  228 , a clamp mount  230 , and a cable guide  232 . A clamp  234  is pivotally secured to the first side plate  224 . 
     A milling cutter  236  is rotatably secured between the flanges  204 , and is operatively connected to the gearbox  218 . The milling cutter is preferably a helical milling cutter. The milling cutter is preferably surrounded on three sides by a cutter shield  238 , exposing only the cutter only at the open end  240  of the milling assembly. 
     The base plate  202  is connected to the handle portion  100  by a spring-centered handle pivot  102 , at one end of the handle  104 . The handle  104  is a shaft, preferably hollow, extending upward from the milling assembly  200  and including controls for the clamp  234 , the rotation of the milling assembly  200 , and the motor  214 . The handle  104  also includes a conduit for power for the motor, preferably in the form of a compressed air passage. The air conduit may be formed by a hollow interior  106  of the handle  104 , operatively connected to the air motor  214 . An air control valve  116  is located along the conduit to control the flow of pressurized air to the motor  214 . 
     The handle  104  includes a means for clamping and unclamping the clamp  234 . Preferred and suggested means include a clamp lever  108 , and a push-pull cable  110  extending from the clamp lever  108 , down the length of the handle, through the cable guide  232 , to the clamp  234 . Pulling the lever  108  outward pushes the cable  110 , pushing the clamp into its closed position, illustrated in FIGS. 3 and 5. Pushing the lever  108  inward pulls the clamp  234  into its open position, illustrated in FIG.  4 . 
     The handle  104  also includes a rotation control lever  112  for the milling assembly. The rotation control lever is secured to a pulley  118  engaging the cable  114 . The cable  114  is a continuous loop, secured at its opposite end to a second pulley  120  secured within the milling assembly  200 . When the rotation control lever  112  is substantially parallel with the handle  104 , the open portion  240  of the milling assembly  200  is directly ahead of the handle, positioned so that if the surface preparation tool  10  is inserted into a hole, the cutter  236  will be positioned to mill the top portion of an underground pipe, illustrated in FIG.  5 . When the lever  112  is pulled 90° in one direction, the milling assembly  200  is pulled by cable  114  to a corresponding 90° offset position, to mill one side of a pipe, illustrated in FIG.  6 . Pulling the lever  112  in the opposite direction by  900  causes the cable to pull the milling assembly 90° in the opposite direction for milling the opposite side of a pipe, illustrated in FIG.  7 . Any portion of the top 180° of a pipe may therefore be milled by positioning the lever  112  in the position corresponding to the desired position of the milling assembly  200 . 
     Referring to FIGS. 8-13M, the alternative hollow handle  154  and clamp  254  for use with the surface preparation tool  10  of the present invention is illustrated. When the lever  156  located on the upper portion of the main handle  154  is activated, the valve (not shown) is shuttled into the open position allowing air to flow through the main handle  154  assembly. The air is then supplied to the air motor  214  by an air tube and pneumatic fittings (not shown). 
     An alternate clamp  254  and modified side plates  256 ,  258  are best illustrated in FIGS. 8-11. While the first side plate  256  is continuous and flat, the second side plate  258  includes the alternate clamp  254 . The clamp arm  254  is rotatably attached to the second side plate  258 , thereby allowing movement of the clamp arm  254  to engaged and disengage the pipe  500 . The L-shaped clamp arm  254  has a clamp roller  260 A,  260 B attached at both ends which assist and guide the engagement and disengagement of the pipe (as described below). 
     Referring to FIGS. 12A-12H and  13 A- 13 M, the clamp arm  254  is actuated by the clamp actuating rollers  260 A,  260 B as they contact the pipe  500 . As the pipe  500  is guided between the shoes  222  and the first  256  and second  258  guide plates, the clamp actuating roller  260 A is pushed by the pipe  500  causing the clamp arm  254  to rotate. As the clamp arm  254  rotates, it traps the pipe  500  between the first  256  and second  258  guide plates and contacts the second clamp actuating roller  260 B until the pipe  500  is secured and in contact with the depth gauge  262 . Depth of cut is regulated by the depth gauge  262  which is held in position by the depth gauge knobs  264  (as best illustrated in FIG. 10A) Once the tool  10  is engaged with the pipe  500 , it operatively rotates as best illustrated in FIGS. 13A-13M. 
     The second tool, the electrofusion valve-clamping tool  20 , is illustrated in FIGS. 14-22. Referring to FIGS. 14-17B, the clamping tool  20  comprises a handle assembly  20 A and a clamping component  20 B. The clamping component  20 B includes a main clamp body  300 , a pair of substantially parallel valve retention arms  302  secured to the clamp body  300 , a clamp paddle  304  pivotally secured to each valve retention arm  302 , a pusher body  306 , a handle  308  secured to the main body, and a pusher slide  310  surrounding the handle  308  and abutting the pusher body  306 . 
     The main body  300  is dimensioned and configured to position the valve retention arms  302  so that a gas main pipe will fit between them. Each valve retention arm defines a slot  312 , dimensioned and configured to mate with and secure one edge  402  of an adaptor  400 . Each clamp paddle  304  is pivotally secured to its corresponding valve retention arm  302  by a pivot passing longitudinally through its central section. 
     The pusher body includes a pair of pusher pins  314  secured at either side. The opposite end of the pusher pins  314  each include a roller  315  abutting the outside edge  316  of one of the clamp paddles  304 . Therefore, when the pusher body  306  moves downward towards the main body  300 , the outer edges  316  of the paddles  304  are pushed downward, thereby raising the inner edges  318  of the paddles  304 . Likewise, raising the pusher body  302  raises the outside edges  316  of the paddles  304 , thereby lowering the paddle&#39;s inside edges  318 . The pusher body  302  is biased away from the main body  300 , preferably by a spring  320 . 
     The handle assembly  20 A of the electrofusion tool comprises a handle shaft  308  extends upward from the main body  300 , terminating in handle  322 . The clamping tool  20  includes means for pushing the pusher body  302  towards the main body  300 , which is preferably in the form of a handle slide  310  surrounding the handle, abutting the pusher body  302 . Pushing downward on the handle slide  310  thereby pushes downward on the pusher body  302 . 
     FIGS. 18-22 illustrate the use of the clamping tool  20 . The clamping tool  20  begins with the pusher  302  in its upper unclamped position, and the paddles  304  in their substantially vertical unclamped position. An adaptor  400  (FIG. 19) slides between the valve retention arms  302 , and the edges  402  are contained within the slots  312 , as illustrated in FIG.  21 . The tool  20  is then lowered onto a gas main pipe  500 , and the handle slide  310  is pushed downward. The pusher pins  314  are thereby pushed downward, pushing the paddles  304  into their substantially horizontal, clamped position, illustrated in FIGS. 21-22. The paddles pull the clamp  20  and adaptor  400  against the gas main pipe. Electrical current passing through electrodes  404  on the adaptor heat and soften the plastic, which in combination with the pressure supplied by the tool  20 , secures the adaptor  400  to the pipe  500 . The tool  20  is then moved horizontally rearward away from adaptor  400 , and raised out of the hole. 
     Referring to FIGS. 23-28, an alternate crank handle  350  and pusher body support right  352  and left  354  main body extension items are illustrated for the electrofusion tool  20 . The alternate crank handle  350  rotates the ears of the paddles  304  into either a horizontal or vertical position. When the tool  20  is lowered onto the prepared pipe  500 , the crank handle  350  is rotated in a clockwise direction (as best illustrated in FIGS.  25 - 26 F). This action draws the main support  300 , pusher body support right  352  and left  354  main body extension items, right and left paddles support  302  and right and left paddles  304  toward the pusher body  306 . The pusher pins  314  exert a downward force on the paddles  304  thereby rotating the paddles  304  and trapping the pipe  500  between the paddles  304  and valve  400 . The crank handle  350  is rotated until the clamp indicator  356  is flush with the top of the handle hinge  358 . The handle hinge  358  is a preset indicator the signals the operator the proper force has been attained. As the tool is properly engaged with the pipe  500  (best illustrated in FIGS.  26 E and  27 ), the electrofusion process is performed. Upon completion, the electrodes are removed and thereafter, the crank handle  350  is rotated counter clockwise until the paddles  304  are in the open position and the tool  20  is removed leaving the valve  400  attached to the pipe  500  (best illustrated in FIGS.  26 F and  28 ). 
     It is to be understood that the invention is not limited to the preferred embodiments described herein, but encompasses all embodiments within the scope of the following claims.