Patent Application
20110233927
This invention relates to a coupling formed by four equal parts each of them in the form of a semi-cylinder having the same external dimensions as the pipe, and edges with holes that must be aligned so as the bolts, nuts and washers can be tightened. The internal portion of the semi-cylinder has at least two cross-section ribs in relief to be sunk as teeth into the pipe at the moment this is being tightened. The main face of the parts of the coupling facing each other to align holes so as to connect the pipes has a flange with a projecting notch for a straight and smooth cut of each pipe to be joined and a groove to place the rubber O-ring. The four parts of the invention are made of polyamide plastic that expand as the moisture increases, thus achieving a better tightening against the pipes as well as a total sealing.
Pipes joined by means of existing couplings are mainly used for conveying fluids and gases. Due to this fact the main purpose of couplings is to achieve total sealing of the pipes to be joined, considering that their function is to prevent fluids or gases from leaking; regardless of whether pipes have a precise and perfect fit with respect to each other. In some couplings, both pipes ends to be joined must be inserted inside the coupling which resembles a tube (such as electrofusion couplings, Plasson, Gegorg Fischer, Straub Open Flex and Aqualok Superfit) while others require the presence of a rubber tube or packing in both pipes (e.g Victaulic, Straub Open Flex couplings) before installing the parts of the coupling, therefore it is not possible to observe the fit or separation between both pipes. In other cases, the design or cutting specification and installation require or allow pipes to be separated (e.g. Masson coupling, electrofusion, Victaulic, etc.).
However, for the purpose of conveying solid elements through an air or liquid flow at high speed, singularities (connectors, valves or any other element installed in the pipe) or separations should not be present throughout the whole interior of the pipe nor in the joints, in order to avoid causing deterioration (dust production and cracked elements) to the product being conveyed. Singularities or separations in pipes contribute to the accumulation of product material, thus affecting the durability of the coupling as well as of the pipe in addition to the fact of causing loss of the solid element being conveyed.
There is a wide variety of couplings in which a skilled technical staff and special equipment are required in order to make the joints (as in the case of the electrofusion coupling). Said special machines (equipment) are used to fuse together the plastic HDPE and the coupling of the state of the art.
For all the couplings in which both pipe ends must be inserted inside the coupling or into cylindrical parts, both pipes must be perfectly circular, although this does not normally occur in the case of HDPE pipes. These couplings have a very precise fit against pipes which makes difficult the installation of the couplings of the state of the art. Due to this fact, a previous work must be performed in order to achieve the circularity of the pipes so as to make easier the insertion of the latter into the coupling.
In all the currently available couplings, additional previous work must be done, since it is necessary to cut the pipes in order to achieve the original circular shape of the pipe before the installation. In order to obtain the final distance between each pipe end inside the couplings, it is necessary to measure and mark the cut ends of the pipes according to the predefined tables provided by the coupling's supplier. Subsequently these marks are used to measure and calculate the final distance at which both pipe ends were separated from each other inside the coupling (as in the case of electrofusion coupling, Victaulic and others).
Several state of the art couplings are known to join pipes, such as the coupling disclosed in document WO 2008/144332 (Dole et al.) dated Nov. 17, 2008. This document describes a two-body coupling with two bolts on each side, which allows to secure the coupling to the pipe. The bolts connect each upper and lower section to a small element which serves to couple and make the joining of these two elements rigid. This system also includes an element made of a flexible material which remains in contact with the pipe ends, providing a certain space between both faces thereof.
Document U.S. Pat. No. 7,144,047 (Dole) dated Jun. 16, 2006 discloses a mechanical coupling for pipes that allows axial, torsion and angular deviations between the pipes joined by the coupling. This coupling is provided with rings wherein each ring has an outside diameter greater than the pipe, said rings are coupled to each pipe end to be joined. Each ring has a circumferential groove for receiving an O-ring. A band is concentrically placed around the rings. This band has an inner surface facing the O-ring tightly. A casing is located around the rings and the band. Said casing is provided with edges that extend radially with respect to the space of pipes, so that they may deviate and keep a radial distance between the casing and the band, This allows the band to be securely fixed over the O-rings and keep a tight sealing.
Document U.S. Pat. No. 7,341,288 (Lundstrom) dated Jun. 30, 2005, discloses a coupling comprising a cylinder at which ends, two rings are located. The coupling is designed to have enough axial restriction, which is achieved by means of four sets of (long) bolts and nuts that tighten the assembly and prevent the rings from moving. Also, fastening to the tube is achieved with the four bolts inserted at specific points of each ring. Each one of these bolts is placed against the pipe until it is secured.
Document U.S. Pat. No. 7,384,076 (Bradley) dated Apr. 27, 2006 discloses a coupling for fluids that are conveyed through high-pressure pipes. This coupling comprises two rings axially connecting each other by means of a set of four bolts. The rings are also radially secured with bolts. Also a small tube is provided over the pipe joint that prevents the joint from moving. The rings are completely fixed to the pipe by means of internal (rubber) grooves that are secured to the pipe by the force produced by the assembly.
Document U.S. Pat. No. 7,490,866 (Webb et al) dated May 19, 2005, describes a device to axially anchorage of a coupling, comprising a system of bolts located on both sides of the coupling and a structure to fasten the pipe to the coupling which consists of a toothed ring and inner grooves.
Document U.S. Pat. No. 6,672,631 (Weinhold) dated Jan. 06, 2004, discloses a coupling secured to the pipe by means of two bolts. This coupling has two parts, each one assembled to each pipe end so as to be joined and they are secured to each other with bolts and shackle-type rigid structure (bow strip). A clamp-type element is provided on top of the coupling which puts pressure over the assembly thus allowing the joint to be tightly secured.
The documents above described disclose different types of couplings, however none of them allows quick joining or connection of the pipes. The present invention generates perfectly circular profiles by means of a straight and smooth out produced by the method of assembly, which achieves a precise and perfect fit between the pipes ends to be joined, without the presence of separations or singularities (connectors, valves or any other element installed in the pipe). The assembly and disassembly is easy, only using conventional hand tools such as saw and combination wrenches (open and box ends).
The present invention refers to a joint assembly for pipe ends comprised by two couplings, wherein a first coupling is located at one end of a first pipe and a second coupling is located at one end of a second pipe. Each coupling has means to secure the appropriate sealing between the inner portion thereof and the outer surface of the pipe. In addition, both couplings have sealing elements, which allow secure joining and coupling their faces, thus generating a watertight seal that prevents the fluid conveyed by the pipes from leaking.
More specifically this invention refers to a coupling comprising four equal parts, and each one of them is shaped in the form of a semi-cylinder having the same outer dimensions as the pipe, as well as edges and holes that must be aligned for bolts, nuts and washers to be tightened. The internal part of the semi-circumference has at least two cross-section ribs in relief that sink as teeth into the pipe when tightened. The main face of the coupling parts facing each other to align the holes so as to connect the pipes is provided with flange having a projecting notch to receive the straight and smooth cut of each pipe to be joined and a groove where the rubber O-ring is placed. The four parts of the invention are made of polyamide plastic that expands as the moisture increases, thus achieving a better tightening against pipes and consequently a total sealing.
For the installation, two parts of the invention must be placed over the pipe end, which can be circular or oval, aligning the holes and tightening by means of the bolts and nuts until edges are fully joined. The pipe takes the inner shape of the two parts of the coupling, which become perfectly circular and tightly secured to the inner ribs in relief. The pipe end protruding from the main face is cut using the projecting rib as a cutting guide. The same operation is performed with the other two parts in the other pipe. The main faces of both parts installed in the pipes are joined by placing the rubber O-ring and aligning the holes no as to tight the bolts with the nuts and washers at the projecting edge.
The figures attached which are included in order to provide a better understanding of the invention, are herein incorporated and are part of this description. The figures illustrate the preferred embodiments and along with the description are useful to explain the principles of this invention.
The present invention provides a joint which can be easily and quickly installed or uninstalled by means of simple and conventional tools that succeed in joining two pipes with a precise and perfect fit in both ends thereof, without requiring a specialized staff or special equipment to that end. HDPE pipes take the semi-circumference shape of the parts of the invention when parts are tightened against the pipes, thus achieving a precise and perfect fit between both ends to be joined. Thus, the coupling between the pipe ends to be joined is similar to only one piece inside, as no singularities or separations are present between the pipes. By using bolts, nuts, washers, the rubber O-ring and the polyamide plastic material of the coupling, total sealing is achieved between the pipes as well as to the outside of them.
A joint assembly for pipes ends is normally comprised by two couplings: a first coupling is located at one end of a first pipe and a second coupling is located at one end of a second pipe. Each coupling has means to secure the proper sealing between the internal portion of its body and the outer surface of the pipe. Also, both couplings are provided with sealing elements that ensure a tight fit of their faces with the coupling, thus generating a watertight seal that prevents the fluid conveyed by the pipes from leaking.
The basic element of the invention comprises one piece of pulyamide plastic which is equivalent to one half of a coupling or, in other words, to a quarter of the joint assembly comprised by two couplings.
In reference to
The upper edge of the front face (16) in the body (2) of the coupling element (1) has a semicircular flange (7) where a plurality of front holes (8) is located. The front face (16) of the body (2) has a semicircular groove (9) concentrically located to the semicircular cavity (17) of the coupling element (1). The lower edge of the front face (16) has a lower perimeter rim or projection (10) provided with a notch (12).
The lower face of the body (2) in the semicircular cavity (17) has a plurality or ribs (11). These ribs are designed to sink or indent into the outer surface of the pipe (14), which will allow fastening the sealing between the coupling element (1) and said pipe (14). As shown by
Likewise, as shown in
As shown in
Once tightening has been performed, a front portion (19) of the pipe (14) is in cantilever in the front faces (16) of the couplings (1a, 1b). By means of the notch (12) of the lower perimeter rim or projection (10) located on the front face (16) it is possible to operate a cutting tool such as a saw to cut flush the front face (16) of the cantilever part (19) of the pipe (14). As shown in
These same operations should be performed for the second pipe to be joined.
Thus,
Between coupling elements (1a, 1b) and coupling elements (1c, 1d) there is an O-ring (13) housed in the semicircular grooves (9), so as to obtain full sealing between the pipes (14a, 14b) when both coupling assemblies are joined through joining means (not shown) such as bolts and nuts that are located in the plurality of front holes (8).
The invention easily succeeds in making HDPE pipes to achieve a circular shape by means of these four coupling elements, since it is only necessary to tight the bolts and nuts in the same coupling against which the pipes are installed. Nevertheless, another part of this invention is also the fact of providing a notch as a cutting guide to remove the excess of the pipe in the same coupling elements so as to obtain a straight and smooth cut.
Succeeding in making the pipes circular having straight and smooth cut of the excess of the pipe by means of the cutting guide are key factors in order to obtain a precise and perfect fit between the pipes without having separations or singularities (connectors, valves or any other element installed in the pipe) in them.
The polyamide plastic material allows total sealing between the coupling elements and the pipe, as well as between the parts on both sides of the coupling when in contact with water or humid environments. This is due to the special characteristic of the polyamide plastic that absorbs humidity and increases its dimensions both to the outside and inside of the coupling elements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 0283-2010 | Mar 2010 | CL | national |
