US3068726A - Drilling machine - Google Patents

Description

Dec. 18, 1962 B. VER lNCDOY DRILLING MACHINE Filed May 4, 1961 3U/fon Ver /Voof/ IN VEN TOR. BYE

/Zaar ATTORA/EVJ United States Patent Oce 3,68,726 Patented Dec. 18, 1952 tas 3,963,726 DRILLNG MACHDIE Burton Ver Nooy, rlfulsa, Ghia., assigner to T. D. Williamson, Inc., Tulsa, kla. Filed May 4, 1961, Ser. No. 167,779 12 Claims. (Cl. 77--4l) This invention relates to improved apparatus for drilling a hole into a vessel such as a pipe, pressure vessel or the like.

It is frequently desirable to cut or drill a hole through the wall of a pipe or other vessel which contains a fluid under pressure. This operation is commonly called hot tapping. Hot tapping is performed in circumstances where it is desired to make a connection to the pipe or other vessel without taking the latter out of operation or removing pressure on fluid therein. For example, hot tapping is often carried out in making connections into pipelines or other vessels containing fluid under pressure to avoid the necessity of shutting down the pipeline, draining and steaming the line to clean it, and then putting it back in service. Similar occasions frequently arise in which it is desired to tap into vessels of other kinds containing uid under pressure.

Hot tapping into a pipeline is usually accomplished by welding a stub pipe or split T onto the pipe to be tapped and then mounting a tapping valve on the stub or on a branch of the T. A tapping machine is mounted on the valve in duid-tight relationship therewith, and the valve is opened so that a cutting device carried by the tapping machine may be run through the open valve to cut the opening in the vessel or pipe. After the opening has been cut, the cutter is retracted and the valve is closed so that the tapping apparatus can be removed without any substantially leakage of uid into or out of the vessel.

A great many types of cutting or drilling apparatus for performing this operation are available on the market today, but such apparatus as is available is relatively complicated and expensive to build. The complicated forms of the present apparatus result in tapping devices which are very heavy so that they are difficult to use.

Apparatus of this type commonly appearing on the market also is diiicult to manufacture in small sizes at acceptable cost. Hot tapping apparatus which is light in weight, small in size and cheap in construction is particularly desirable in the general utilities field; for example, in use for tapping into ordinary gas and Water supply mains of municipalities for the connection of distribution lines.

It is accordingly a principal object of this invention to provide a simplified, light weight tapping apparatus which is portable and easy to operate but which can withstand the high iiuid pressures which may be encountered in cutting into pipes or other vessels containing fluid under pressure.

Many of the hot tapping devices of the prior art have an additional disadvantage in that the mechanism feeding the cutter against the work piece is a positive drive. In apparatus of this type, the cutter is advanced a predetermined distance for each revolution thereof without respect to the resistance encountered by the cutting tool. In other words the cutter is fed into the work piece at a substantially constant linear rate of feed whether the cutting duty be heavy or light. These machines usually are constructed to have a feed rate which would be desirable with average resistance to the cutting tool, but the resistance encounted in making hot taps varies greatly from job to job. As a result, the cutter is fed too slowly during light cutting duty and too fast when the resistance on the cutter is heavy. Feeding too fast against heavy Aresistance frequently results in burning or breaking the cutting teeth or elements and destruction of the eciency of the cutter.

It also has been conventional to provide hot tapping machines with a two-speed feeding mechanism. A high speed feed mechanism is used to advance or retract the cutter from cutting position rapidly, and the low speed feed is used during the actual cutting operation; but since the drive is positive in both high and low speed mechaisms, devices of this type have been subject to the disadvantage that the operator may fail to change from high to low speed at the proper time and thus jam the cutter into the vessel to be cut at high speed with resulting darnage to the cutter.

it has also been suggested that a slipping clutch be provided inside the housing of such devices which would permit change from high speed to low speed feed automatically upon the cutter encountering resistance. Machines having a slipping clutch inside the housing efectively prevent damage to the cutter from striking work at a high feed rate, but this construction requires that the machine be disassembled when the force applied through a slipping clutch is to be varied.

Another object is to provide a drilling apparatus particularly useful in hot tapping operations in which the feeding rate is automatically reduced on contact of the cutter with the work piece, and in which the feeding force applied to the cutter may be varied at will during the cutting operation.

Another object is to provide a drilling apparatus of this type which automatically limits the feeding force to a selected maximum, and in which the selected maximum may be changed during the cutting operation as conditions may require.

Another object is to provide a drilling apparatus of this type in which a cutter is advanced at rapid rate toward a work piece or retracted therefrom at high rate of speed and in which the feed rate is reduced automatically on contact of the cutter with a work piece by a simplified drive mechanism.

Another object is to provide a drilling apparatus of this type which is light, portable, simple in construction, low in cost, rugged and long wearing in use.

Other objects and advantages will become apparent to those skilled in the art from consideration of the following description and attached drawings.

In the present invention, the feeding device is simplified by forming the housing in two substantially cylindrial interiitting parts having matching screw threads on their opposed surfaces. It is not necessary that both the interfitting parts have screw threads over a length of their surfaces corresponding to the length of travel of a boring bar. For example, one of the intertting parts of the housing may have only a short threaded section engaging a series of threads on the other part of sufficient length to provide the required travel distance for the drilling operation. Thus, the housing itself forms the major part of an effective feed mechanism.

One of the intertitting parts of the housing, preferably the inner part, has an end adapted to be attached to a pipe or other vessel in fixed relationship therewith. This end may be threaded or may carry a flange or other type of attachment which normally will be secured to the housing of a tapping valve or to a nipple connected to a vessel. A simple, one-piece boring bar having an end adapted to carrying a bit or other cutter extends entirely through the housing and ts the bore of the inner housing part which may serve as a bearing for the boring bar. A suitable drive mechanism is provided for driving the boring bar, and this mechanism preferably includes a drive member rotatable coaxially with the bar. For serv-V ice with cutters of relatively small sizes, it s preferred that the drive mechanism include an arm fixed to the boring bar and turned manually. This arm preferably' carries a plate, which may be integral therewith, disposed across the end of the housing opposite to the cutter to form an end closure of the housing.V

Friction means is provided for driving that part of the housing not` connectible to a vessel, and this means preferably is a split friction band having a cleft in its periphery and lined with a suitable high friction kmaterial such as brake lining. This band is arranged outside the housing to be driven by the drive member. This ar- Y rangement preferably includes a web attached to or integral with the drive arm disposed within the cleft in the periphery of the friction band. Y

Manually operable means outside the housing are provided for varying the Vfriction of the band upon the exterior of the housing part at will, thus providing simple means for increasing or decreasing drive pressure on a cutter attached to the boring bar as circumstances may require. The adjustment means preferably includes a bolt passing through the web and attached to the ends of the spring band to move the ends of the band closer together or farther apart by manipulation of a wing nut.

It will thus be seen that the drive mechanism is a very simple one since one part of the housing a held stationary'by its connection to a vessel and the other part Vhas friction applied to its outer surface tending to rotate it. The matching threads wil1 ca use the housing parts to telescope with a spiral motion into or out of collapsed position.

In the attached drawings, wherein like characters are unsed to designate like parts: v

FIG. l is an eleveation, partly in section of a device of the present invention attached to a pipeline for a hot tapping operation; FIG. 2 is an enlarged detail of the upper end of the device of FIG. 1, partly in section; and

FIG. 3 is a cross section of the device shown inV FIG.

2 on the line 3-3.

The particular tappingvvmachine illustrated in the draw- -Y ingsl comprises a housing having an outer part Sand an inner part 6 tting into the housing part 5 and having an end 7 adapted to be connected to a pipeline 10 in ixed relationship therewith. In hot tapping operations, the connection is usually made by connecting the end 7 to the housing of a tapping valve 8 which in turn is connected to a nipple 9 welded or otherwise firmly at-r Y lower end' 12a of a boring bar 12A which exends entirely through the housing; This boring bar is of such size as to Iit into the inner. housing part 6 so that theY housing part' serves as. a bearing for the boring bar and 'V prevents excessive wobble during rotation of the bar.

The. particular outer part ofY the housing illustrated is threaded substantially throughout its length on the inside thereof with threads 13; A short section of the inner part 6' is threaded at'its end opposite end 7 with threads 14 matching threads 13 so that rotation of the upper part 5, when part 6 is stationary, of the housing drives the outer partv to or from telescopically collapsed relationship with housing part 6.

The boringv bar is rotated by drive means designated generally as 15 and preferably comprising Van arm 16 rotatable coaxiallyv with the boring bar and fixed thereto by a nut 18. The upper end of the boring, bar just beneath nut 18 is of non-circular cross section, preferably hexagonal, as illustrated, and ts into a matching openingfin the drive means. Thus, it willk be seenv that rotation of arm 16 by means of handle 17 around the axis of the boring bar will advance the boring bar and the cutter attached thereto into drilling direction or in the reverse direction.

The arm 16 preferably has a plate 19 attached to, or integral therewith, disposed to close the upper end of the housing. housing should not be Vtight enough to cause excessive friction but should be suiciently close to prevent dirt and extraneous matter from entering housing part 5.

The driving means 15 has a -Web 20 attached to or preferably made integral therewith. The web 20 extends along the exterior of housing part 5 but spacedv from it for a distance suiiicient to be received between ends 23' of a spring friction band having a cleft 22 in its periphery The band V21 has a lining 24 of high friction material, Y

such as brake lining, and extends around and presses upon the exterior surface of housing part 5. Friction between the band and part 5 applies a force tending toV rotate part 5 upon screw threads 14 of part 6 and thus to move part 5 to or from telescopically collapsed position with part '6. A means for adjusting the friction. and thus selecting a maximum driving force is provided and is illustrated as a bolt 26 through ends 23 of theV band and web 20, arranged to be tightened or loosened. by manipulation of a wing nut 27.

The upper end of the boring bar has a shoulder 30, shownonly in FIG. 2, adapted to receive an anti-friction bearing disposed to prevent excessive friction between the boring bar and housing member 5. 'Ihis bearing comprises upper and lower raices 32 and 31, respectively, and a series of friction-reducing members, illustrated as balls 33, between the races. The upper race 32 is held in position by ay pair of snap rings 28 and 29 disposed in suitable grooves in housing part 5 and in the boring bar, respectively. 'J'Ihe anti-friction bearing and snap ring assembly serve to reduce friction between the boring bar and housing when the boring bar is rotated at a speed greater than that of the housing and the cutter is in en-Y gagement with the vessel to bebored, and prevents. part 5 of the housing from being driven out of the friction ring.

In order to control pressure of fluid from within line 10 when the line has been penetrated by the cutter 11, a seal 3- preferably disposed in a groove 35 inthe housing part 6 is arranged to maintain aV fluid-tight seal between the boring bar and housing. Y

Operation of the apparatus described above is believed to be obvious from the description. When it is desired to make a hot tap, a nipple 9 is attached in leak-proof relationship to the line to be tapped, preferably by welding tothe outside of the line. A tapping valve 8 is attached in lipid-tight relationship with nipplev 9, and the housing part 6 is attached to the housing of vfthe tapping valvefwith the boring bar and cutter in retractedV position; The tapping valve is then opened and the boring bar is advanced rapidly to cutting position byrotation of the arm 16 which drives the housing part 5 by friction from band 21. Only light friction is necessary to cause the housing part 5 to move rapidly across the threaded section 14 of the inner part 6 until the cutter 11 strikes the vessel to be tapped. Y

Contact of the cutter 11 with the wall of the line 10 cannot damage the cutter because ofthe light frictionY exerted by band 21 on the housing part 5. This small amount of friction allows the drive means to continue Y the circumstances of the particular work andinay doV The iit of this plate upon the end of the so during the cutting operation. He may adjust the wing nut 2,7 at any time to apply any degree of friction necessary under the circumstances.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference Ato other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1. Apparatus for drilling into a vessel comprising in combination a housing, including inner and outer substantially cylindrical intertting parts having matching screw threads on their opposed surfaces, one of said parts having an end connectible to a vessel in iixed relationship therewith; a boring bar rotatably disposed in the housing; means for rotating the boring bar, including a drive member outside the housing rotatablecoaxially with the boring bar; and friction means coaxial with the boring bar for rotating that part of the housing not connectible to a vessel, including a friction band around and pressing upon an exterior surface of the last-mentioned part arranged to be driven bythe drive member on rotation thereof.

' 2. Apparatus for drilling into a vessel comprising in combination a housing, including inner and outer substantially cylindrical interfitting parts having matching screw threads on their opposed surfaces, one of said parts having an end connectible to a vessel in fixed relationship therewith; a boring bar rotatably disposed in the housing; means for rotating the boring bar, including a manually operable drive arm outside the housing rotatable coaxially with the boring bar; and friction means coaxial with the boring bar for rotating that part of the housing not connectible to a vessel, including a friction band around and pressing upon an exterior surface of the lastmentioned part arranged to be driven by the manually operable drive arm on rotation thereof.

3. Apparatus for boring into a vessel comprising 1n combination a housing, including inner and outer substatnially cylindrical interitting parts having matching screw threads on their opposed surfaces, said inner part having an end connectible to a vessel in fixed relationship therewith; a boring bar rotatably disposed in the housing; means for rotating the boring bar, includlng a manually operable drive arm outside the housing rotatable coaxially with the boring bar; friction means coaxial with the boring bar for rotating the outer part of the housing, including a friction band surrounding and pressing upon an exterior surface of said outer part arranged to be driven by the manually operable drive arm on rotation thereof.

4. Apparatus for boring into a vessel comprising in combination a housing, including inner and outer substantially cylindrical interlitting parts having matching screw threads on their opposed surfaces, said inner part having an end connectible to a vessel in fixed relationship therewith; a boring bar rotatably disposed in the housing; means for rotating the boring bar, including a manually operable drive arm outside the housing rotatable coaxially with the boring bar, including friction 7 5. Apparatus for boring into a vessel comprising in combination a housing, including inner and outer substantially cylindrical intertting parts having matching screw threads on their opposed surfaces, said inner part having an end connectible to a vessel in fixed relationship therewith; a boring bar rotatably disposed in the housing; means for rotating the boring bar, including a drive member outside the housing rotatable coaxially with the boring bar; a web on the drive member; friction means for rotating the outer part of the housing, including a split spring band having .a cleft through the periphery thereof surrounding and pressing upon an exterior surface of said outer part of the housing having said cleft in the periphery arranged to include the web between opposite sides thereof and a bolt passing through the web arranged to apply pressure forcing the ends of the band together.

6. Apparatus for Vboring into a vessel comprising in combination a housing, including inner and outer substantially cylindrical interiitting parts having matching A screw threads on their opposed surfaces, the inner of said parts having an end connectible to a Vessel in fixed relationship therewith; a boring bar rotatably disposed in the housing; means for rotating the boring bar, including a manually operable drive arm outside the hous- `ing rotatable coaxially with the boring bar; a web on the drive arm and a rotatable plate on the drive arm forming an end closure of the housing; friction means for rotating the outer partV of the housing, including a friction band having a cleft in its periphery arranged to include said web in said cleft and means :for applying and releasing pressure tending to close said cleft; and a thrust bearing having a race carried by a shoulder on the boring Ibar, a race carried by said outer member and friction-reducing members disposed between said races.

7. Apparatus for boring into a vessel comprising in combination Ia housing, including inner and outer substantially cylindrical interlitting parts having matching screw threads on their opposed surfaces, one of said parts having an end connectible to a vessel in Huid-tight fixed relationship therewith, a boring bar rotatably disposed in the housing; means for rotating the boring bar, including a drive member outside the housing rotatable coaxially with the boring bar; friction means coaxial with the boring bar for rotating that part of the housing not connectible to the vessel, including a friction band around and pressing upon an exterior surface of the lastmentioned part arranged to be driven by the drive member on rotation thereof, and means in the housing lfor maintaining a fluid-tight seal between the boring bar and that part of the housing connectible to a vessel.

8. Apparatus for boring into a vessel comprising lin combination a housing, including a pair of inner and outer substantially cylindrical interfitting parts having matching screw threads on their opposed surfaces, one of said parts having an end connectible to a vessel in uid-tight relationship therewith; a boring bar rotatably disposed in the housing; means for rotating the boring bar, including a manually operable drive arm outside the housing rotatable coaxially with the boring bar; friction means coaxial with the boring bar for rotating that part of the housing not connectible to a vessel, including a friction band substantially surrounding and pressing upon an eX- terior surface of the last-mentioned part arranged to be driven by rotation of the manually operable drive arm on rotation thereof; and means for maintaining a uidtight seal between the boring bar and that part of the housing connectible to a vessel.

9. Apparatus for boring into a vessel comprising in combination a housing, including a pair of inner and outer substantially cylindrical interiitting parts having matching screw threads on their opposed surfaces, the inner of said parts having an end connectible to a vessel in fluid-tight fixed relationship therewith; a boring bar rotatably disposed in the housing; means for rotating the boringbar, including a drive member outside the housing rotatable coaxially with the boring bar; friction means for rotating the outer part of the housing including a friction band around and pressing upon an exterior surface of said outer part arranged to be driven by the drive memberfon rotation thereof and means for adjusting pressure of the band; and externally operable means for maintaining a uid-tight seal between the boring bar and the inner part of the housing.

10. Apparatus for boring into a vessel comprising in combination a housing, including a pair of innerrand outer substantially cylindrical interfitting parts having matching screw threads on their opposed surfaces, said inner part having an end connectible to a vessel in fluid-tight xed relationship therewith; a boring bar rotatably vdisposed in the housing; means for rotating the boring bar, including a manually operable driveM arm outside the housing rotatable coaxially with the boring bar; friction `means for rotating the outer part of the housing, including a friction band surrounding and pressing upon an exterior surface of said outer part arranged to be driven by the drive arm on rotation thereof, said band being a split spring handhaving a cleft in its periphery and a lining ofhigh friction material, externally operable means for adjusting pressure of said band; and means for maintaining a fluid-tight seal between the boring bar and the inner part of the housing.

1l. Apparatus for boring into a vessel comprising in combination Ya housing, including a pair of inner and outer substantially cylindrical interiitting parts having matching screw threads on their opposed'surfaces; means foi' connecting an end ofthe inner part to a vessel in Huid-tight xed relationship therewith; a boring bar rotatably disposed in the housing; means for rotating the boring bar, including a drive member outside the housing rotatable coaxially with the boring bar and a web on the drive member; friction means for rotating the outer part of the housing, including a split spring band, having a cleft in,

its periphery, disposed to press uponv an exterior surface of the outer part arranged with the web Within the cleft in the periphery of the band and a bolt through the web' disposed to apply pressure to the band; and means' for maintaining a fluid-tight seal between the boring bar and Y drive arm projecting from the drive arm in a direction Y parallel to the housing beyond the adjacent end offthe housing; friction means for rotating the outer part of the housing, including a split spring friction band having 1a' cleft through its periphery receiving said web, said band pressing upon an exterior surface of the outer part of the housing, externallyV operable means for increasingaudV` decreasing pressure of said band; and means Vfor main# taining a huid-tight seal between the boring bar and the inner part of the housing, including a groove in the inner part ofthe housing facing the boring bar and an O-ring seal disposed in the groove in contact With the boring bar. References Cited inthe file of this patent UNITED STATES PATENTS Tuirord May 19, V1874I Mueller et al. ..-n Apr.v17, 19751 OTHER REFERENCES German application 1,087,430, Aug; 18, 1960.

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