TECHNICAL FIELD

[0001] This invention relates to the field of hot tapping, in general, and more specifically to a hot tapping drill apparatus and an associated method for hot tapping.

BACKGROUND ART

[0002] The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

[0003] Hot tapping or pressure tapping is a method of making a connection to existing piping or pressure vessels without the interrupting or emptying of that section of pipe or vessel. This generally means that a pipe or vessel, such as a tank, can continue to be in operation whilst maintenance or modifications are being done to it.

[0004] The process of hot tapping is also used to drain off pressurised casing fluids and add test points or various sensors, such as temperature and pressure, to existing piping or pressure vessels. Hot taps can range from a ½ inch hole designed for something as simple as quality control testing, up to a 48-inch tap for the installation of a variety of ports, valves, t-sections or other pipes.

[0005] A general hot tap procedure comprises installing a hot tap saddle or weld nozzle along with a valve and pressure testing the assembly before attaching hot tap drill apparatus. The installed valve is opened, hot tapping completed by drilling into the pipe or vessel while pressure is contained within the saddle or hot tapping apparatus .

[0006] The drill is then retracted and the valve closed, whereafter fluid is drained from the saddle and the hot tapping machine is removed. The tapped valve is now ready for tie-in or equipment to be inserted. In addition, hot tapping is also typically the first procedure in line stopping, where a hole saw is used to make an opening in a pipe so a line plugging head can be inserted.

[0007] Often, hot tapping must be done in confined spaces, such as excavations, where other utilities may be close by, such as electricity cables, gas supply, water pipes, data cables, etc. As a result, space for hot tapping under certain circumstances is typically limited. Applicant has identified a need in the art for a hot tapping drill apparatus able to be used in confined spaces where conventional hot tapping drills cannot operate.

[0008] The current invention was conceived with this shortcoming in mind in an attempt to propose, at least in part, possible improvements in amelioration of such shortcomings in the art of hot tapping drill apparatus.

SUMMARY OF THE INVENTION

[0009] According to a first aspect of the invention there is provided a hot tapping drill apparatus comprising:

a housing;

a rotation shaft arranged within the housing and comprising at least two secondary rotation shafts telescopically arranged and keyed to allow transmission of torque, one end of said rotation shaft extending outside the housing and configured to operatively receive a drill bit; a translation shaft arranged within the housing and comprising at least two secondary translation shafts telescopically arranged via a complementary threaded engagement to allow for telescopic translation of said secondary translation shafts due to relative threaded rotation;

a link assembly linking the rotation and translation shafts to allow independent rotation of the rotation shaft whilst coupling translation of said shafts;

a first actuator configured to operatively actuate the rotation shaft to rotate; and

a second actuator configured to operatively actuate the translation shaft, wherein rotation of the drill bit is operatively facilitated via the rotation shaft and translation of said drill bit relative to the housing is operatively facilitated via the translation shaft.

[0010] Typically, the housing is configured to operatively engage with a hot tapping valve arrangement or saddle via a suitable saddle engagement.

[0011] Typically, the housing defines at least one handle to facilitate manual handling and positioning of the drill apparatus.

[0012] Typically, the translation and rotation shafts are coaxially arranged within said housing.

[0013] Typically, the translation shaft is arranged about the rotation shaft, i.e. the rotation shaft is internal to the translation shaft.

[0014] Typically, the link assembly comprises a collar defined on one end of the rotation shaft, said collar operatively complementarily captured within a guide bearing on the translation shaft, so that translation of the translation shaft telescopes the rotation shaft whilst said rotation shaft is able to rotate freely.

[0015] Typically, the two secondary rotation shafts are complementarily keyed by one secondary rotation shaft defining a protruding key operatively slidably engaged in a complementary channel defined by the second rotation shaft, said key and channel enabling relative translation whilst allowing transmission of torque via said rotation shaft.

[0016] Typically, first actuator comprises a pneumatic, hydraulic and/or electromechanical actuator configured to operatively actuate an end of the rotation shaft distal from the drill bit end.

[0017] Typically, the first actuator is configured to actuate the rotation shaft via a ring and pinion gear arrangement.

[0018] Typically, the second actuator comprises a pneumatic, hydraulic, electromechanical and/or mechanical actuator configured to actuate one of the at least two secondary translation shafts to allow for telescopic translation of the other secondary translation shaft due to relative threaded rotation via the complementary threaded engagement.

[0019] Typically, the second actuator is configured to actuate the translation shaft at an end thereof distal from the link assembly .

[0020] Typically, the second actuator is configured to actuate the translation shaft via a worm drive arrangement.

[0021] Typically, the drill apparatus includes at least one guide bar configured to guide telescopic translation of one secondary translation shaft relative to the other secondary translation shaft.

[0022] Typically, the at least one guide bar is coaxially arranged with the translation shaft within the housing.

[0023] Typically, the drill apparatus includes a plurality of guide bars arranged in parallel within the housing.

[0024] According to a second aspect of the invention there is provided a method for hot tapping, said method comprising the steps of :

providing drill apparatus in accordance with the first aspect of the invention; and

hot tapping a vessel or pipe using said drill apparatus.

[0025] Typically, the step of hot tapping includes the step of actuating the rotation shaft, via the first actuator, in order to rotate the drill bit.

[0026] Typically, the step of hot tapping includes the step of actuating, via the second actuator, the translation shaft to translate the drill bit away from or towards the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

The description will be made with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic perspective view representation of one embodiment of a hot tapping drill apparatus in accordance with as aspect of the invention;

Figure 2 is a diagrammatic side-sectional view representation of the hot tapping drill arrangement of Figure 1; Figure 3 is a diagrammatic side-sectional view representation of the hot tapping drill arrangement of Figure 1 showing a translation shaft in a translated or extended position; and

Figure 4 is a diagrammatic exploded-view representation of a translation and rotation shafts of the hot tapping drill apparatus of Figure 1.

DETAILED DESCRIPTION OF EMBODIMENTS

[0027] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention to the skilled addressee. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. In the figures, incorporated to illustrate features of the example embodiment or embodiments, like reference numerals are used to identify like parts throughout.

[0028] With reference now to the accompanying figures, there is shown one example of a hot tapping drill apparatus 10. In the exemplified embodiment, the drill apparatus 10 comprises a housing 12, a rotation shaft 14 for operatively receiving a drill bit at one end 16 thereof, a translation shaft 18, a link assembly 22, a first actuator 24 and a second actuator 26, all described in more detail below.

[0029] The rotation shaft 14 is arranged within the housing 12 and generally comprises at least two secondary rotation shafts 14.1 and 14.2 that are telescopically arranged and keyed to allow transmission of torque, the one end 16 of the rotation shaft 14 typically extending outside the housing 12 and configured to operatively receive a drill bit (not shown) .

[0030] Similarly, the translation shaft 18 is arranged within the housing 12 and typically comprises at least two secondary translation shafts 18.1 and 18.2 that are telescopically arranged via a complementary threaded engagement 20 in order to allow for telescopic translation of the secondary translation shafts 18.1 and 18.2 due to relative threaded rotation. In this manner, rotating (in this example) the inner secondary translation shaft 18.1 results in the outer secondary translation shaft 18.2 being extended (as seen in Figure 3) along the threaded engagement 20 relative to said inner secondary translation shaft 18.1.

[0031] The link assembly 22 operatively links the rotation and translation shafts 14 and 18 to allow independent rotation of the rotation shaft 14 whilst coupling translation of both shafts 14 and 18 together. In this manner, as described below, the rotation shaft 14 enables operative drilling via a drill bit attachable at end 16, whilst translation shaft 18 facilitates telescopic extension or retraction of said drill bit.

[0032] In the exemplified embodiment, the translation and rotation shafts 14 and 18 are coaxially arranged within the housing 12. The translation shaft 18 is arranged about the rotation shaft 14, as shown, i.e. the rotation shaft 14 is coaxially internal to the translation shaft 18. However, the skilled addressee will appreciate that the rotation shaft 14 can also be arranged about the translation shaft 18, or the like, and that such other embodiments are possible and within the scope of the present invention .

[0033] The link assembly 22 typically comprises a collar 32 defined on one end 16 of the rotation shaft 14, as shown, said collar 32 operatively and complementarily captured within a guide bearing 34 on the translation shaft 18. In this manner, operative translation of the translation shaft 18 telescopes the rotation shaft 14 whilst the rotation shaft 14 is able to rotate freely in order to facilitate drilling.

[0034] In order to enable this functionality, the two secondary rotation shafts 14.1 and 14.2 are generally complementarily keyed via one secondary rotation shaft 14.1 defining a protruding key 36 or the like which is operatively and slidably engaged in a complementary channel 38 defined by the second rotation shaft 14.2. This keyed arrangement of key 36 and channel 38 enables relative translation between secondary rotation shafts 14.1 and 14.2 whilst allowing transmission of torque via said overall rotation shaft 14. As before, the skilled addressee will appreciate that other arrangements are possible whereby translation with torque transmission can be achieved, such arrangements being within the scope of the present invention.

[0035] By apparatus 10 having this configuration of the two secondary rotation shafts 14.1 and 14.2 enabling relative translation whilst still allowing transmission of torque via said overall rotation shaft 14, apparatus 10 is able to be used in confined spaces where conventional hot tapping drills cannot operate. Apparatus 10 can be manufactured more compact than conventional hat tapping drills, while allowing similar drill distances, i.e. lengthwise translation of the two secondary rotation shafts 14.1 and 14.2, with similar torque transmission.

[0036] Also included are first and second actuators 24 and 26. The first actuator 24 is configured to operatively actuate the rotation shaft 14 to rotate, e.g. in order to rotate a drill bit attachable at end 16. The second actuator 26 is configured to operatively actuate the translation shaft 18 as needed, wherein rotation of the drill bit is operatively facilitated via the rotation shaft 14 and translation of said drill bit relative to the housing 12 is operatively facilitated via rotation shaft 14 18, as described above.

[0037] Apparatus 10 enables decoupling of the translation actuator from the rotation actuator, providing additional benefit. By having the rotation shaft 14 and translation shaft 18 separately actuated, as described, allows better drilling control in a compact package, providing further improvement over conventional hot tapping drill apparatus. For example, a higher force actuator may be used for the first actuator 24 to operatively actuate the rotation shaft 14 to rotate a drill bit for drilling, with a lower force actuator required for the second actuator 26 to actuate the translation shaft 18. Of course, variations hereon are possible and within the scope of the present invention.

[0038] Typically, the first actuator 24 may comprise a pneumatic, hydraulic and/or electromechanical actuator configured to operatively actuate an end of the rotation shaft 14 distal from the drill bit end 16, as shown. In the exemplified embodiment, the first actuator 24 is configured to actuate the rotation shaft 14 via a ring and pinion gear arrangement 40, including suitable bearings 50 and bushing 52, as shown. However, the skilled addressee will appreciate that other arrangements are possible whereby the first actuator 24 may actuate the rotation shaft 14.

[0039] Similarly, the second actuator 26 may comprise a pneumatic, hydraulic, electromechanical and/or mechanical actuator configured to actuate one of the at least two secondary translation shafts 18.1 and 18.2 to allow for telescopic translation of the other secondary translation shaft due to relative threaded rotation via the complementary threaded engagement 20, as described above. Due to the threaded arrangement 20, an outer or inner translation shaft 18.1 or 18.2 may be actuated to achieve relative translation, depending on requirements. Typically, the second actuator 26 is configured to actuate the translation shaft 18 at an end thereof distal from the link assembly 22, as shown. In the exemplified embodiment, the second actuator 26 is configured to actuate the translation shaft 18 via a worm drive arrangement 42, but other arrangements are possible and within the scope of the present invention.

[ 0040 ] The housing 12 is typically configured to operatively engage with a hot tapping valve arrangement or saddle (not shown) via a suitable saddle engagement 28, such as via a suitable flange, or the like. The housing 12 also typically defines at least one handle 30 to facilitate manual handling and positioning of the drill apparatus 12.

[ 0041 ] The drill apparatus 10 further generally includes at least one guide bar 44 configured to guide telescopic translation of one secondary translation shaft 18.2 relative to the other secondary translation shaft 18.1, as shown. Typically, the at least one guide bar 44 is coaxially arranged with the translation shaft 18 (and coaxial rotation shaft, by extension) within the housing 12. The exemplified embodiment of the drill apparatus 10 includes a plurality of guide bars 44 arranged in parallel within the housing 12 via a suitable mechanical brace 46, as shown, with suitable guide followers 48.

[ 0042 ] The skilled address will appreciate that the present invention includes an associated method for hot tapping, said method typically comprising the steps of providing an embodiment of drill apparatus 10 and hot tapping a vessel or pipe using said drill apparatus 10 as is generally known in the art. [0043] This step of hot tapping typically includes the step of actuating the rotation shaft 14, via the first actuator 24, in order to rotate a drill bit operatively attached to end 16, as described above. The step of hot tapping further generally includes the step of actuating, via the second actuator 26, the translation shaft 18 to translate the drill bit on end 16 away from or towards the housing 12, as required.

[0044] Applicant believes is particularly advantageous that the present invention provides for a hot tapping drill apparatus 10 useful for performing hot tapping operations in confined spaces. In particular, Applicant believes the telescopic coaxial rotation and translation shafts 14 and 18 described herein provide novel and inventive improvements to the art of hot tapping drill apparatus .

[0045] Optional embodiments of the present invention may also be said to broadly consist in the parts, elements and features referred to or indicated herein, individually or collectively, in any or all combinations of two or more of the parts, elements or features, and wherein specific integers are mentioned herein which have known equivalents in the art to which the invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. In the example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail, as such will be readily understood by the skilled addressee.

[0046] The use of the terms "a", "an", "said", "the", and/or similar referents in the context of describing various embodiments (especially in the context of the claimed subject matter) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising, " "having, " "including, " and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. No language in the specification should be construed as indicating any non-claimed subject matter as essential to the practice of the claimed subject matter.

[0047] Spatially relative terms, such as "inner," "outer," "beneath, " "below, " "lower, " "above, " "upper, " and the like, may be used herein for ease of description to describe one element or feature's relationship to another element (s) or feature (s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly .

[0048] It is to be appreciated that reference to "one example" or "an example" of the invention, or similar exemplary language (e.g., "such as") herein, is not made in an exclusive sense. Various substantially and specifically practical and useful exemplary embodiments of the claimed subject matter are described herein, textually and/or graphically, for carrying out the claimed subject matter.

[0049] Accordingly, one example may exemplify certain aspects of the invention, whilst other aspects are exemplified in a different example. These examples are intended to assist the skilled person in performing the invention and are not intended to limit the overall scope of the invention in any way unless the context clearly indicates otherwise. Variations (e.g. modifications and/or enhancements) of one or more embodiments described herein might become apparent to those of ordinary skill in the art upon reading this application. The inventor (s) expects skilled artisans to employ such variations as appropriate, and the inventor (s) intends for the claimed subject matter to be practiced other than as specifically described herein.

[ 0050 ] Any method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed .