Technical Field

The present invention relates generally to a pipe joining and/or separating apparatus and, more particularly but not limited to a pipe joining and/or separating apparatus for joining and separating ribbed pipes and/or fittings.

Background of the Invention

Corrugated polypropylene pipes, often also generally referred to as ribbed pipes, are often used as stormwater, drainage and irrigation pipes and for reinforced light-weight service ducting. Such ribbed pipes have an optimised profile design which offers a high level of strength and reliability, as well as economy and superior flow rates. Also, the use of ribbed plastic pipes has been increasing in popularity in recent years due to the ongoing issue of silicosis caused by concrete products.

The abovementioned ribbed pipes are commonly provided in elongate sections which need to be joined before use. It however takes considerable force to join the pipe sections due to the rubber ring joint provided at the end of each pipe section for sealing purposes. Previous attempts to join ribbed pipe sections include simply using a crowbar for pushing the pipe sections towards one another. This method however has multiple shortcomings, some of which are pertinent to the soft or hard ground on which the pipe sections are placed on site making it difficult for the user to try and get a suitable hole for the crowbar to lever off. Another shortcoming of this method is that an appropriate impediment is required as one end of the pipe section has to be "blocked" against something so as to enable a first pipe section to remain stationary while a second pipe section is being into it for joining. To be effective and efficient, such a system requires two people, one at the joint and the other at the crowbar end.

Prior art also includes a pipe joining apparatus disclosed in US Patent number 3471919A for joining cast iron sewer pipes of small diameters. This apparatus is designed to push fittings on rather than quickly joining long length of pipes. It only works on smooth pipes with an enlarged "bell" end with the engagement of the pulling side of the apparatus occurring directly behind the bell/collar. The receiving end of this apparatus is designed to sit over the end of the fitting and/or a length of chain continues to the end of a pipe length with a hook to engage the pipe. This apparatus/method has the following shortcomings: i) it is unsuitable for use on HDPE or "plastic" pipe as the chain would tear the plastic at the end of the pipe length; ii) during operation, it pulls at the top of the pipe has the tendency to lift one end of the pipe and hence impact on the efficacy of the apparatus; iii) it is limited to working on smooth pipes with an enlarged bell end; the apparatus must be placed at the collar; and iv) it does not have the ability to push/separate joined pipes for inspection of poor joints or removal of damaged pipes.

It is an object of the present invention to provide an apparatus for joining and/or separating first and second pipe sections which may overcome or at least ameliorate the above shortcomings or which will at least provide a useful alternative.

Summary of the Invention

According to one aspect of the present invention, there is provided an apparatus for joining and/or separating first and second pipe sections, the first pipe section having a first elongate body with a socket end, the second pipe section having a second elongate body with a spigot end; the apparatus including: a first yoke structure having: a lever yoke having first and second yoke arms which are spaced apart; a first frame forming or supporting a first brace yoke adapted to firmly engage a selected part of one of the first or second elongate bodies; wherein the lever yoke being pivotally joined to the first frame; a second yoke structure having: a second frame forming or supporting a second brace yoke adapted to firmly engage a selected part of the other of the first or second elongate bodies; and a first pair of joining means each having a first end connected to the first yoke structure and a second end connected to the second yoke structure.

Preferably, the first and second ends of each of the joining means are joined to the respective first and second yoke structures at a predetermined height such that the joining means when taut are at substantially the same level as a centre plan that extends across the first and second pipe sections.

Preferably, the first yoke structure includes a brace between the first and second yoke arms and provides a substantial gap between the top of the first frame and the brace so as to facilitate pivotal movement of the lever yoke over a large angle. As such, the lever yoke may be capable of travelling a long distance without the brace being obstructed by the top of the first pipe section.

Preferably, the first pair of joining means are detachable and replaceable so as to allow the first and second yoke structures to be spaced different distances apart.

Preferably, the first yoke structure includes a second class lever.

Preferably, the first end of each of the joining means is detachably connected to one of the yoke arms and the second end detachably connected to the second frame.

In a preferred embodiment, each of the first and second brace yokes includes an arch adapted to be snugly received in a circumferential groove defined by adjacent circumferential ridges provided in the selected part of each of the respective first and second elongate bodies which are corrugated. Preferably, the arch is so configured as to conform to the curvature of the groove surface covering at least the top half of the circumferential groove. Preferably, when the lever yoke is pulled, the arch is capable of firmly urging onto a side of one of the adjacent circumferential ridges thereby causing corresponding movement of the first or second pipe section.

Alternatively, each of the first and second brace yokes includes a curved bar with a pair of parallel ribs. Preferably, the ribs are internal ribs.

Preferably, the first frame includes first and second terminals pivotally connected to the first and second yoke arms respectively. More preferably, each of the first and second yoke arms has an extremity, the first and second terminals of the first frame are pivotally connected to the extremities of the first and second yoke arms respectively.

Preferably, the second frame also includes third and fourth terminals.

Preferably, the first pair of joining means includes first and second tethers. More preferably, each tether is a chain. Even more preferably, the first end of each of the first and second tethers is connected to the first frame at a point which is on or near the horizontal centre plane of the first pipe section when the first frame and the first elongate body are in engagement. Most preferably, the first end of each of the first and second tethers is connected to the first and second terminals of the first frame respectively. Likewise, the second end of each of the first and second tethers is preferred to be connected to the second frame at a point which is on or close to the horizontal centre plane of the second pipe section. The second end of each of the first and second tethers is preferred to be connected to the third and fourth terminals of the second frame respectively.

Preferably, during installation for joining, in the first instance, the lever yoke is disposed in a first position where it is inclined towards the second yoke structure with the brace resting on the top of the pipe, and the first and second yoke structures are placed apart such that the tethers are taut. Preferably, after installation, the lever yoke is pivotally movable to a second position where it is inclined away from the second yoke structure thereby causing the first and second pipe sections to be pulled towards one another. Preferably, this results in penetration of the spigot end into the socket end.

Preferably, the apparatus further includes a pair of elongate spacing means for separating the joined first and second pipe sections, the elongate spacing means being adapted in use to lock the first and second yoke structures at desired operating positions where they are kept apart by a pre-determined distance. More preferably, each of the pair of elongate spacing means is movably or removably connected to the first and second frames respectively. Even more preferably, each of the first and second elongate spacing means has one end pivotally connected to the first and second yoke arms respectively via an elbow joint and an opposite end adapted to removably engage the second frame. Most preferably, the elbow joints are adapted to facilitate moving of the elongate spacing means between an uplifted position and a drop-down position where the opposite ends are brought into engagement with the second frame at one or more chosen locations.

Preferably, each of the elongate spacing means is a rod including a pin at the opposing end. More preferably, the second frame includes two limbs. Even more preferably, each limb includes one or more holes adapted to receive the pin when the rod is in a drop-down position. Most preferably, when in the drop-down position, the rod is substantially parallel to the horizontal centre plane of the first and second pipe sections.

Preferably, during installation for separating, in the first instance, the lever yoke is disposed in the second position where it is inclined away from the second yoke structure, and the first and second yoke structures are joined but kept apart at fixed chosen locations via the dropped down rods. In operation, the lever yoke is pivotally movable to a first position where it is inclined towards the second yoke structure thereby causing the second pipe section to be pushed away from the first pipe section. Preferably, this results in detachment or withdrawal of the spigot end from the socket end.

Brief Description of the Drawings

Preferred embodiments will now be described by way of example only with reference to the accompanying figures, in which:

Figure 1 is a front perspective view of a pipe joining and/or separating apparatus in accordance with a first preferred embodiment of the present invention;

Figure 2 is a rear perspective view taken of the apparatus of Figure 1;

Figure 3 is a front perspective view of the apparatus of Figure 1 showing one elongate spacing means being dropped down and another one in a drop-down position;

Figure 4 shows a perspective view of the apparatus of Figure 1 before engaging two pipe sections to be joined;

Figure 5 illustrates a side view of the apparatus of Figure 1 about to be amounted onto the two pipe sections which are engaged with one another via the spigot and socket ends;

Figure 6 is a side view of the apparatus of Figure 1 illustrating the first yoke structure sitting onto the first pipe section with the level yoke being inclined towards the second yoke structure before the joining operation;

Figure 7 is cross sectional view showing the first yoke structure of the apparatus of Figure 1 before engaging the first pipe section;

Figure 8 is a cross sectional view showing the first yoke structure of the apparatus of Figure 1 after engaging the first pipe section;

Figure 9 is a side view of the apparatus of Figure 1 illustrating the apparatus of Figure 1 with the lever yoke moved to a position where it's inclined away from the second yoke structure after the joining operation;

Figure 10 is a side view of the apparatus of Figure 1 before engaging the already joined first and second pipe sections;

Figure 11 is a side view of the apparatus of Figure 1 after engaging the joined first and second pipe sections with the lever yoke being inclined away from the second yoke structure and the elongate spacing means being placed in a dropdown position before the joining operation; and

Figure 12 is a side view of the apparatus of Figure 1 with the lever yoke being moved to a position where it's inclined towards the second yoke structure for separation of the joined first and second pipe sections.

Figure 13_is a perspective view of a pipe joining and/or separating apparatus in accordance with a second preferred embodiment of the present invention;.

Figure 14 is a magnified view of a circled portion (labelled B) of the first yoke structure shown in Figure 13;

Figure 15 is a perspective view of a portion of the yoke arm of the first yoke structure of the apparatus of Figure 13 being connected to one end of a chain;

Figure 16 is a perspective view of a portion of the second yoke structure of the apparatus of Figure 13 being connected to another end of the chain shown in Figure 15;

Figure 17 is a side view of the apparatus of Figure 13 mounted on the joined first and second pipe sections; and Figure 18 is a cross sectional view of the apparatus and pipe sections shown in Figure 17.

Detailed Description of the Drawings

It will be appreciated that the present invention is primarily designed to be applied on corrugated pipes (also commonly known as ribbed pipes) which are tubes with a series of parallel ridges and grooves on their surfaces. However, it is contemplated that the present invention may be used on pipes with a smooth surface as well. This pipe can be manufactured of steel or plastic such as high-density polyethylene (HDPE) or PVC. It should be noted that the apparatus of the present invention may be adapted to fit onto StormPRO™ and other ribbed pipes which range in size from 150mm through to 900mm. A corrugated pipe is described herein as an exemplary embodiment of the present invention.

First Preferred Embodiment

Referring to Figures 1 to 3, an apparatus 10 for joining and/or separating first and second pipe sections is shown. As shown in Figure 4, the first pipe section 12 has a first elongate body 16 with a socket end 19. The second pipe section 14 has a second elongate body 18 with a spigot end 20. The apparatus 20 has a first and second yoke structures 22 & 24 which are joined by a first pair of joining means. The first yoke structure 22 has a lever yoke 26 with a shaft 1 and a first frame 28. The lever yoke 26 has first and second yoke arms 30 & 32 which are spaced apart. In the present embodiment, the first frame 28 supports a first brace yoke 34 which is configured to firmly engage a selected part of the first elongate body 16. The lever yoke 26 is pivotally joined to the first frame 28. The second yoke structure 24 has a second frame 36 which in the present embodiment supports a second brace yoke 38 which is configured to firmly engage a selected part of the second elongate body 18. In the present embodiment, the first pair of joining means are tethers which are in the form of metallic chains 40 & 42. Each of the chains 40 & 42 has a first end 44, 46 affixed to the yoke arm 32, 30 and a second end 48, 50 affixed to the second frame 36.

As best shown in Figures 5 and 6, each of the first and second brace yokes 34 & 38 take the form of an arch 64, 66 adapted to be snugly received in a circumferential groove 68, 72 (for example) defined by adjacent circumferential ridges 70, 74 (for example) provided in the selected part of each of the respective first and second elongate bodies 16 &18 which are corrugated. The arch 64, 66 is so configured as to conform to the curvature of the groove surface covering at least the top half 76 of the circumferential groove 68, 72. When the lever yoke 26 is pulled, the arch 64 is capable of firmly urging onto a side of one of the adjacent circumferential ridges 74, 70 thereby causing corresponding movement of the first or second pipe section 16, 18.

As shown in Figures 1 to 9, the first frame 28 has first and second terminals 52, 54 which are pivotally connected to the first and second yoke arms 32 & 30 respectively. Each of the first and second yoke arms 32 & 30 has an extremity 56, 58. The first and second terminals 52 & 54 of the first frame 28 are pivotally connected to the extremities 56 & 58 of the first and second yoke arms 32 & 30 respectively so as to provide two fulcrums to facilitate pivotal movement of the lever yoke 26. The second frame 36 also has third and fourth terminals 60 & 62.

Turning to Figures 4 to 9, the first end 44, 46 of each of the first and second chains 40 & 42 is connected to the first frame 28 at a point which is on or near the horizontal centre plane A of the first pipe section 12 when the first frame 28 and the first elongate body 16 are in engagement. The first end 44, 46 of each of the first and second chains 40 & 42 is connected to the first and second yoke arms 32 & 30 of the first frame 28 respectively at a predetermined height such that when the first frame 28 and the first elongate body 16 are in engagement, each of the taut chains 40 & 42 is at substantially the same level as the centre plan A which extends across the first and second pipe sections 12 & 14. Likewise, the second end 48, 50 of each of the first and second chains 40 & 42 is connected to the second frame 36 at a point which is on or close to the same horizontal centre plane A of the second pipe section 14. The second end 48, 50 of each of the first and second chains 40 & 42 is connected to the third and fourth terminals 52, 54 of the second frame 36 respectively.

Referring to Figures 5 to 9, during installation for joining, in the first instance, the lever yoke 26 needs to be disposed in a first position (see Figure 6) where it is inclined towards the second yoke structure 24. It is important for the first and second yoke structures 22 & 24 to be placed apart such that the chains 40 & 42 are taut. Mounting of the apparatus 10 onto the first and second pipe sections 12 & 14 is achieved by engaging the first and second yoke structure 22 & 24 with the first and second pipe sections 12 & 14 respectively, as shown in Figures 7 and 8. In operation, the lever yoke 26 is then pivotally moved to a second position where it is inclined away from the second yoke structure 26 (see Figure 9) thereby causing the first and second pipe sections 12 & 14 to be pulled towards one another. This results in full penetration of the spigot end 20 into the socket end 19.

Turning now to Figures 3, 4, 10 to 12, the apparatus 10 further includes a pair of elongate spacing means for separating already joined first and second pipe sections 12 & 14. The elongate spacing means in the present embodiment are in the form of rods 78 & 80. The rods 78 & 80 are configured in use to lock the first and second yoke structures 22 & 24 at desired operating positions where they are kept apart by a predetermined distance which in the present embodiment is basically the length of the rods 78 & 80. Each of the pair of rods 78 & 80 is movably or removably connected to the first and second frames 28 & 36 respectively. Each of the rods 78 & 80 has one end 82, 84 pivotally connected to the first and second yoke arms 32 & 30 respectively via an elbow joint 86, 88 and an opposite end 90, 92 adapted to removably engage the second frame 36. The elbow joints 86 & 88 facilitate moving of the rods 78 & 80 between an uplifted position (see Figures 1 and 10) and a drop-down position (see Figures 3, 11 and 12) where the opposite ends 90 & 92 are brought into engagement with the second frame 36 at one or more chosen locations. As best shown in Figure 3, Each of the rods 78 & 80 includes a pin 94, 96 at the opposing end 92, 90. The second frame 36 includes two limbs 98 & 100. In the present embodiment, each limb 98, 100 has three holes 102, 104 (see Figures 2 and 3) which are configured and arranged to receive the pin 94, 96 when the rod 78, 80 is in a drop-down position. When in the drop-down position, the rod 78, 80 is substantially parallel to the horizontal centre plane A of the first and second pipe sections 12 & 14.

Referring to Figures 10 to 12, during installation of the apparatus 10 for separating already joined first and second pipe sections 12 & 14, in the first instance, the lever yoke 26 is disposed in the second position (see Figure 11) where it is inclined away from the second yoke structure 24, and the first and second yoke structures 22 & 24 are joined but kept apart at fixed chosen locations via the dropped down rods 78 & 80, as illustrated in Figure 11. As shown in Figure 12, in operation, the lever yoke 26 is pivotally moved to a first position where it is inclined towards the second yoke structure 24 thereby causing the second pipe section 14 to be pushed away from the first pipe section 12. This results in detachment or withdrawal of the spigot end 20 from the socket end 19.

Second Preferred Embodiment

Another exemplary embodiment of the apparatus of the present invention will now be described where parts similar or identical in form and/or function are similarly numbered and with the letter "A" appended.

Referring to Figures 17 and 18, the apparatus 10A is shown. The apparatus 10A has first and second yoke structures 22A and 24A which are configured differently from those of apparatus 10. As shown in Figures 13 and 14, the first yoke structure 22A includes a lever yoke 26 with a shaft 1 and a first frame 28A which forms a first brace yoke 34A. In the present embodiment, the first brace yoke 34A is in the form of a curved bar with a pair of internal parallel ribs 110 which are designed in use to be snugly received in two circumferential grooves provided on the first elongate body 16 of the first pipe section 12. As such, the first brace yoke 34A is firmly interlocked with the first elongate body 16 when the first frame 28A and the first elongate body 16 are in engagement. The second yoke structure 24A has a second frame 36A forming a second brace yoke 38A. The second brace yoke 34A is also in the form of a curved bar having a pair of internal parallel ribs 112, as shown in Figure 18. The ribs 112 are configured to engage with the circumferential grooves provided on the second elongate body 18 of the second pipe section 14.

Turning to Figures 15 and 16, in the embodiment, the apparatus 10A has a pair of chains. Each chain 42 (for example) has a first end detachably connected to yoke arm 30 of the first frame 28A of the first yoke structure 22A and a second end detachably connected to the second frame 36A of the second yoke structure 24A. As illustrated in Figures 15 and 16, each end is equipped with fastening means in the form of a D- shackle 116, 122 which is configured to be connected to a bracket 118, 124 via a locking pin 120, 126. As such, the chains 42 & 40 are detachable from the first and second yoke structures 22A & 24A respectively and may be replaced by other chains of different lengths. This offers a significant benefit of allowing the first yoke structures 22A & 24A to be spaced wide apart to get around or avoid being obstructed by services when the first and second pipe sections to be joined are situated in a trench.

Referring to Figure 17, the first and second ends of the chain 42 are connected to the yoke arm 30 of the first frame 28A and the second frame 36A respectively at a predetermined height such that the chain 42 when in a taut state is at substantially the same level as the centre plan A which extends across the first and second pipe sections 12 & 14. This is important as in both the present and the first embodiments, as if the taut chains are located too high or low off the centre plan A, once the lever is moved to effect joining, either the first and second pipe sections 12 & 14 will be lifted off the ground, or one or both of the socket and spigot ends 19 & 20 will end up being crushed and damaged as a result of slipping and engaging at an inappropriate angle. As shown in Figures 17 and 18, the second yoke structure 24A includes a removable handle 114 which makes transportation and storage easier.

As best shown in Figures 1 and 13, in both the first and second embodiments described above, the first yoke structure 22, 22A includes a brace 130 between the first and second yoke arms 32 & 30 and provides a substantial gap 128, 128A between the top of the first frame 28, 28A and the brace 130 so as to facilitate pivotal movement of the lever yoke 26 over a large angle. As such, the lever yoke 26 is capable of travelling a long distance without the brace 130 being obstructed by the top of the first pipe section 12. This offers a significant advantage of enabling the apparatus 10, 10A to operate with a one-pull (or push depending on where the user is standing) motion once it is placed on the pipe sections 12 & 14 to be joined.

Referring to Figures 1, 15 and 16, it will be appreciated that in both of the embodiments described above, the first pair of joining means, ie. the chains 40 & 42, are detachable and replaceable so as to allow the first and second yoke structures 22 & 24 and 22A & 24A to be spaced different distances apart. This offers the benefits of enabling the apparatus 10, 10A to be fitted onto first and second pipe sections 12 & 14 of different lengths at different locations, and allowing utilisation of joining means of different lengths to get around services when the pipe sections 12 & 14 to be joined are already situated in a trench for example.

It should also be noted that in both embodiments described above, the first yoke structure 22, 22A includes a second class lever where the load is in the middle between the fulcrum and the effort to pull the pipe sections 12 & 14 together. The second class lever offers the benefit of allowing the force/effort to move in the same direction as the load, as illustrated by the arrows 132, 134 & 136 shown in Figure 9, for example.

It will be appreciated that the apparatus 10, 10A of the present invention is capable of being used once it is fitted over the top of pipe sections. With only one lever yoke in the centre, the apparatus 10, 10A is capable of pulling the pipes together straight. The chains 40 & 42 can be looped up with a receiving hoop onto the shaft 27 for the apparatus to be carried one-handedly to the next joint.

Now that preferred embodiments of the present invention have been described in some detail, it will be appreciated that the apparatus 10, 10A of the present invention may offer at least the following advantages:

1. it enables joining of two pipe sections by one person without requiring additional tools;

2. it is easy and simple to install and operate requiring only one person;

3. it is lightweight and compact;

4. it has minimal moving parts with no adjustment required to fit the pipe;

5. it facilitates large pipe sections with a relatively long diameter to be joined;

6. it can be placed anywhere along the length of pipe sections with the use of adjustable chains; it does not need to engage a raised "bell" at the collar end of a pipe section to function (note: ribbed pipe sections do not necessarily have a raised bell at the collar end);

7. it delivers a high level of efficiency and efficacy by 'grabbing' both of the two pipe sections and pulling them together during joining operation instead of pushing one pipe section into another;

8. it is applicable on pipe sections without a collar or a spigot end and the first and second yoke structures are reversible in terms of their engagement with the first and second pipe sections;

9. it is capable of achieving full engagement of the first and second pipe sections, ie. the joint, with only one motion of the yoke lever thereby maximising the efficiency of each joint; 10. it is capable of functioning in any of the grooves along the pipe sections so long as the joint is located between the first and second yoke structures;

11. it includes two parts joined as one by way of the joining means which is capable of acting as a guide on the distance apart for the first and second yoke structures to work; the distance can be altered at any time by way of replacing existing joining means with joining means of different lengths to overcome obstacles encountered when joining pipe sections around other services

Those skilled in the art will also appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. The first yoke structure may be brought into engagement with either the first pipe section and the second yoke structure with the second pipe section, and vice versa. It is contemplated that in an alternative embodiment, the first and second frames may form the first and second brace yokes. In other words, the first and second frames may be shaped and configured to function as brace yokes as well without requiring a supporting frame. All such variations and modifications are to be considered within the scope and spirit of the present invention the nature of which is to be determined from the foregoing description.