GB2140729A - Portable flange facing and turning machine - Google Patents

Abstract

A portable facing and turning machine is provided for refacing and/or regrooving flanges on pipes or tubes. The machine comprises mounting means whereby the machine can be mounted on an end of a pipe or tube to be machined, cutting means (15), means for rotating the cutting means about the axis of a flange to be machined, and rack and pinion means for continuously moving the cutting means (15) radially of a flange to be machined, enabling a continuous helical groove to be cut in the face of a flange. <IMAGE>

Description

SPECIFICATION Portable facing and turning machine This invention relates to portable facing and turning machines for refacing and/or regrooving flanges on pipes and tubes.

Pipes and tubes are frequently connected together by means of flanges thereon. To ensure a good seal between the ends of the connected pipes and tubes the mating faces of the flanges are machined flat and have a groove or grooves cut therein to improve sealing efficiency. With the passage of time the seal between mating flanges sometimes breaks down so that leaks occur and when this happens it is frequently necessary to reface and/or regroove the mating surfaces of the flanges. The present invention has as its object to provide a portable facing and turning machine which enables the flanges on pipes or tubes to be refaced and/or regrooved in situ.

The present invention provides a portable facing and turning machine for refacing and/or regrooving flanges on pipes and tubes, the machine comprising mounting means whereby the machine can be mounted on the end of a pipe or tube having a flange to be refaced and/or regrooved, cutting means for rotating the cutting means about the axis of a flange to be refaced and/or regrooved, and rack and pinion means for continuously moving the cutting means radially of a flange to be refaced and/or regrooved, whereby a continuous helical groove can be cut in the face of a flange.

The cutting means may comprise a tool holder mounted on one end of said rack and a cutting tool mounted in the tool holder. The tool holder may be slidably mounted on guide means, such as guide bars which extend through annular bearings in the tool holder, for movement radially of a flange to be refaced and/or regrooved.

The machine according to the present invention may comprise a driven shaft for rotating the cutting means about the axis of a flange to be refaced and/or regrooved and an harmonic drive for transmitting drive at a stepped down ratio from the driven shaft to the pinion of the rack and pinion means for moving the cutting means radially of a flange to be refaced and/or regrooved. Preferably the machine comprises a stationary sun gear and a planet gear movable in planetary motion about the sun gear, the planet gear comprising the input to said harmonic drive.

The harmonic drive may comprise an output gear and gears may be provided for transmitting drive from said output gear to said pinion.

The pinion of the rack and pinion means is driven to move the rack longitudinally and so move the cutting means radially of a flange to be refaced and/or regrooved. Preferably clutch means, such as a dog clutch, is provided for disengaging the drive to the pinion.

Stop means may be provided for disengaging said clutch when the cutting means reaches the limit of its travel radially of a flange to be refaced and/or regrooved. Said clutch may be manually disengageable to enable the cutting means to be positioned radially of a flange to be refaced and/or regrooved prior to machining of the flange.

Said mounting means may comprise collet means which can be inserted into an end of a pipe or tube which has means movable into tight engagement with the internal surface of the pipe or tube. Said mounting means may comprise centering means whereby the cutting means can be caused to rotate concentri caliy with a flange to be refaced and/or regrooved. Such centering means may comprise gripping means which can be moved radially outwards into engagement with the internal surface of a pipe or tube, such gripping means being spaced axially of a pipe or tube and being independently adjustable to enable centering of the cutting means.

The present invention will be more particularly described with reference to the accompanying drawings in which: Figure 1 is a perspective view of a known tube end profiling machine which provides the drive for the illustrated embodiment of the present invention.

Figure 2 is a perspective view of part of one embodiment of a machine according to the present invention, Figure 3 is a view similar to Fig. 2 but with further parts added, Figure 4 is a sectional view through a harmonic drive forming part of a machine of the present invention, Figure 5 is a sectional view showing a clutch mechanism forming part of the machine of the present invention, and Figure 6 shows in perspective and plan views a collet/sleeve means for mounting the machine of the present invention in the end of a pipe or tube.

Fig. 1 illustrates a known tube end profiling machine. Rotary power is provided at the output shaft 1 derived from the drive motor 2 via the right angle drive 3. A central shaft 4 with a hexagon 5 at one end and an expanding collet 6 at the other end, is provided.

Furthermore, the shaft 4 has a screwed portion on which runs an indexing wheel 7.

Rotation of the indexing wheel 7 indexes the drive along the central shaft 4. Rotation of the central shaft 4 via the hexagon 5 with the collet 6 held stationary, expands the collet. If the collet is placed within a bore of relevant size, locking will take place.

Fig. 2 shows the facing and turning machine body 8, drive sleeve 9, harmonic drive housing 10, rack pinion 11, rack bar 12, slide bars 13 and 14, and cutting tool carrier 15. Fig. 3 shows a further build up of the machine. In addition to the parts shown in Fig. 2, Fig. 3 shows a sun-gear 16, planetary input gear to harmonic drive 17, output gear from harmonic drive 18, transverse drive gear 19, change gears 20 and 21, torque plate 22, torque stops 23, top cover 24 and bottom cover 25.

Fig. 4 shows a cross-section through the harmonic drive. Extra parts, not previously shown, are harmonic drive shaft 26, hardened thrust washer 27, wave generator 28, flex spline 29, dynamic spline 30, circular spline 31 and output coupling 32.

Fig. 5 illustrates the clutch mechanism.

Clutch driver 33 is pressed into engagement with rack pinion 11 by disc springs 34. Drive is from change gear 21 via a keyed shaft to clutch driver 33 and hence to rack pinion 11.

The clutch is released by turning the clutch actuator wheel 35. This turns the clutch actuator eccentric 36. The clutch plate 37 mounted on clutch bracket 38 is thus depressed and hence the clutch driver 33 is disengaged.

Fig. 6 illustrates the collet/sleeve device previously mentioned. Upper collet balls 39a and lower collet balls 39b are retained by an upper garter spring 40a and a lower garter spring 40b respectively. I Upper actuator balls 41a and lower actuator balls 41b are biased downwards by socket actuator screws 42.

Actuator rods 43 transmit the force from the relavent actuator screws 42 to the lower actuator balls 41b. The upper and lower actuator mechanisms are contained within a collet sleeve 44. The upper mechanisms are circumferentially equi-spaced, as are the lower actuator mechanisms. However, each lower actuator mechanism is angularly displaced by an equal amount from its respective upper actuator mechanism. Socket spider arms 4G, also equi-spaced, are interspaced between the actuator mechanisms at the upper end. Operation is as follows. The collet/sleeve with spider arms attached, is inserted into the pipe bore until the spider arms rest against the flange. A gauge post with a dial gauge mounted on a rotatable arm (not illustrated) is inserted into the bore of the collet/sleeve.The dial gauge is rotated in contact with the flange, whilst adjustments are made to the upper and lower actuator mechanisms. When the dial gauge indicates conformity within the required tolerances, the actuator mechanisms are fully tightened so that the collet balls grip the pipe bore. At this stage the gauge post and dial gauge are removed altogether as are the spider arms. The expanding collet attached to the facing and turning machine is now introduced into the collet/sleeve bore and made to grip. With the cutter rotating, actuation of the indexing wheel 7 enables refacing or regrooving to commence.

Various modifications are possible with respect to optimisation of the grip of the collet/sleeve to the pipe bore, for example: (1) The collet balls 39a and 39b can be replaced by elongate splines with a cam at the rear face.

(ii) The garter springs 40a and 40b can have hinged elongate splines attached such that these grip the pipe bore when spring expansion takes place.

Fig. 7 illustrates the complete facing and turning machine operating upon a pipe flange.

Whilst the illustrated embodiment has been shown as deriving its drive from a known pipe end profiling machine it will be understood that it can derive its drive from a suitable motor mounted thereon, e.g., a pneumatic or electric motor.

It will be readily understood that the present invention provides a very compact and lightweight facing and turning machine which enables flanges on pipes or tubes as small as 1" (25mm) nominal bore to be machined using angled cutters as well as flanges.on quite large pipes or tubes of up to 20" (508mm) nominal bore to be worked upon.

Claims (15)

1. A portable facing and turning machine for refacing and/or regrooving flanges on pipes and tubes, the machine comprising mounting means whereby the machine can be mounted on the end of a pipe or tube having a flange to be refaced and/or regrooved, cutting means, means for rotating the cutting means about the axis of a flange to be refaced and/or regrooved, and rack and pinion means for continuously moving the cutting means radially of a flange to be refaced and/or regrooved, whereby a continuous helical groove can be cut in the face of a flange.

2. A portable facing and turning machine according to claim 1, wherein the cutting means comprises a tool holder mounted on one end of said rack and a cutting tool mounted in the tool holder.

3. A portable facing and turning machine according to claim 2, wherein the tool holder is slidably mounted on guide means for movement radially of a flange to be refaced and/or regrooved.

4. A portable facing and turning machine according to claim 3, wherein said guide means comprises spaced guide bars which extend through annular bearings in the tool holder.

5. A portable facing and turning machine according to any one of the preceding claims, comprising a driven shaft for rotating the cutting means about the axis of a flange to be refaced and/or regrooved and an harmonic drive for transmitting drive at a stepped down ratio from the driven shaft to the pinion of the rack and pinion means for moving the cutting means radially of a flange to be refaced and/or regrooved.

6. A portable facing and turning machine according to claim 5, comprising a stationary sun gear and a planet gear movable in planetary motion about the sun gear, the planet gear comprising the input to said harmonic drive.

7. A portable facing and turning machine according to claim 5 or 6, comprising an output gear from the harmonic drive and gears for transmitting drive from said output gear to said pinion.

8. A portable facing and turning machine according to any one of the preceding claims, wherein the pinion of the rack and pinion means is driven and wherein clutch means is provided for disengaging the drive to the pinion.

9. A portable facing and turning machine according to claim 8, wherein said clutch means comprises a dog clutch.

10. A portable facing and turning machine according to claim 8 or 9, wherein stop means is provided for disengaging said clutch when the cutting means has reached the limit of its travel radially of a flange to be refaced and/or regrooved.

11. A portable facing and turning machine according to claim 8, 9 or 10, wherein said clutch is manually disengageable to enable the cutting means to be positioned radially of a flange to be refaced and/or regrooved prior to machining of the flange.

12. A portable facing and turning machine according to any one of the preceding claims, wherein said mounting means comprises collet means which can be inserted into an end pipe or tube and having means movable into tight engagement with the internal surface of the pipe or tube.

13. A portable facing and turning ma chime according to claims 12, wherein said mounting means comprises centering means whereby the cutting means can be caused to rotate concentrically with respect to a flange to be refaced and/or regrooved.

14. A portable facing and turning machine according to any one of the preceding claims comprising a pneumatic motor for providing drive to the cutting means.

15. A portable facing and turning machine substantially as herein described with reference to the accompanying drawings.