US2500469A - Metalworking tool - Google Patents

Description

P. REKETTYE ETAI- METAL WORKING TooL March 14, 195o Filed Feb. '7, 1946 BY wel] wam .f ATTORNEY Patented Mar. 14, 1950 METALWORKING- Toor.

Paul Rekettye and Carl A. Maxwell, Akron, Ohio., assignors to The Babcock & Wilcox Company, Eoclzleigh, N. J., a corporation of NewJersey Application February 7, 1946, Serial No. 646,034

7` Claims.

. The present invention relates to improvements in metaly working tools, and more particularly to tools for refacing the seats for the covers used in ei'ecting pressure tight closure of handhole or access openings in vessels included in thepressure parts ol vapor generating equipment and similar apparatus normally operating under a substantial pressure.l

The customary cover seat for a handhole opening in a steam boiler steam or water header, for example, is a machine inished plane surface on the inside face of the header wall, the surface being annular and normal to the edge walls oi the handhole opening. The complementary cover extends over the handhole and is bolted against the seat by external means to provide a fluid tight joint between the seat and the cover.

When inthe course of operating service the seat becomes pitted or scored by the action of the iluid in the header, or is otherwise marred or damaged in a manner which might hinder the attainment of fluid tight contact between the cover and seat, it is necessary that one or both of the co-acting surfaces be renished. No great difficulty isexperienced in refinishing the handhole cover since it can be removed from the header, but refacing the seat on the inner wall of the header, in the field, is diicult, and a compact, accurate and readily mountable tool is of particular advantage in facilitating the seat refacing work.

Heretofore various types of f1ycutters and grinders have been suggested for such seat refacing work, but theyhave been considered inadequate due to the required methods of' Support, Ydir liculty of insertion and withdrawal from the handhole opening and the uncertainty of tool position control. V

it is therefore the main object ofthe present invention to provide a portable seat refacing tool assembly capable of lield use in accurately refacing the inner wall .seats surrounding openings in pressure vessels. Another and more specic object is to provide a simple and compact tool assembly of the character described capable of being mounted in a position closely associated with the surface to be renished. A further speci-lic object isv to provide apparatus for refacing the handhole seat in a boiler or economizer header or the like which is characterized by its ability to be manually adjustable for depth of cut while the radial position of the cutting tool is maintained in the desire-d width of cut responsive to a iiuid pressure. A further specic object is to provide a device for refacing a handhole seat wherein the cutting tool assoeiatedtherewith is retractable fromits cutting position for ease of installation and removal of the device. f

The various features of novelty which characterize our invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages andspeciiic objects attained by its use, ref.- erence should be had to the accompanying drawings and descriptive matter in which. We have illustrated and described a preferred embodiment oi our invention. i

Of the. drawings:

Fig. 1 is an. elevation of a handnole seat. re.- facing t'ool. constructed in accordance with the present invention and in operative position with respect to a header handhole;

Fig. 2 is a planv View of the `apparatus shown in Fig. l;r

Fig. 3 is an elevation, largely in. cross-section, taken on the line 3'-3. of Fig..2;

Fig. 4: is a cross-section of the apparatus taken onV the line 4 4 of Fig. 3; and

Fig. 5 is across-section of the apparatus taken on the line 5--5 of Fig. 3.

In` the drawings, ar tool assembly constructed in accordance with the:- present invention is illustrated in position to renish the seatl l0 of a handhole H in the wallV l2 of a boiler yor economizer header. The headery in which the .handhole is located may be circular in transverse cross-section, or itmay be square or of other shape withoutA altering the general method of tool support and operation hereinafter described. The handhole il' andv hand-hole seat l2, as indicated in Fig. 2, are of the conventional elliptical shape to permit the entrance and seating of an elliptical shaped handhole cover which is held in position `by external clamps (not shown) in a well known manner.

The machine in general includes a shaft or spindle I4 projecting through the handhole opening and rigidly supported in a position normal to the plane of the handhole seatvlil and centrall'y positioned relative to the handhole open ing. A hub I5 is rotatably mounted on the spindle l`4 and arranged to support and posi'- tion a refinishing or cutting tool i6 in contact withthe seat lll. The hub is constructed to provide a radial movement of the tool into proper cutting position in response to pneumatic pressure, while an adjustment of the tool i6 for the desired depth of cut is accomplished by a vrotation of the spacer.

manual adjustment of the hub I5 along the axis of the spindle I4.

As shown in the drawings, the outer end of` the spindle I4 is supported by a frame I1 bearing on the exterior of the header wall I2 and straddling the handhole, while its inner end is supported by a clamp I8 having two diametrically opposite arms bearing on the interior surface of the header wall and also straddling the handhole. An opening 2D in the central portion of the frame I1 ts the outer end of the spindle which has a projecting reduced threaded section 2I and a machined shoulder 22, `so that a lock nut 23 tightly drawn against the shoulder also rests upon the outer surface of the frame. The spindle projects through the handhole into the header and has a threaded end section 24 in the clamp I8. With the nut 23 in place on the shoulder 22, the frame I1 and clamp I3 are drawn into position abutting the outer and inner surfaces of the header wall I2 by screwing the spin- Vdle into the clamp through the use of a wrench engaging a lsocket 25 in the outer end section 2l of the spindle.

It will be observed that with the construction described the outer end of the spindle I4 is maintained in a fixed relation within the frame I1,while any change in the thickness of the header wall for different handhelds will cause a corresponding axial change in the position of the clamp I8 on the inner end 24 of the spindle. The advantage of this construction are described hereinafter.

The hub includes a rotatable spacer 26 of cylindrical shape having a hollow interior threaded to engage a correspondingly threaded feed sleeve 28. A girth gear 21 mounted on the upper portion of the spacer 26 is arranged to receive and transmit rotational movement to the hub` assembly. The lower portion of the spacer 25 is provided with a socket 3D of rectangular crosssection arranged to support and guide the movement of a tool holder or plunger 3I of rectangular cross-section in a direction normal to the axis of This socket is formed with an open bottom, closed by a removable cover plate 32, and an open end in one side of the spacer through which the plunger 3l projects in radially guided movements. The socket and 'plunger can also be made of circular cross-section, if desired.-

The central portion of both the cover plate 32 and a transverse partition 33 which defines the top wall of the socket 36 are machined to provide an opening for the press t therethrough of a bearing sleeve 34. The bearing sleeve has an internal bore adapted to rotatably t the spindle I4. Within the upper portion of the spacer the sleeve 34 is extended to engage in a ksliding fit with a bushing 35 which is pressed into one end of the feed sleeve 28.

The feed sleeve 28 is spaced from the inner side of the frame I1 by a bronze washer 36 and is further provided with a balltype thrust bearing 31 inserted between an annular shoulder on the spindle I4 and an annular internal shoulder on the upper end of the feed sleeve 28. In the assembly of the hub described, the spacer 26 and the feed sleeve 28 are mounted for rotation about the spindle I4, with the feed sleeve rotating in a fixed axial position relative to the spindle as y determined by the washer 36 and the thrust bearing 31. While the spacer 26 also rotates with the feed sleeve about the spindle I4, its axial position relative to the spindle may be manually adjusted by relative rotation between the spacer and the feed sleeve by means of the threaded connection therebetween. During such an axial positioning of the spacer, the bearing sleeve will move longitudinally with the spacer between the spindle I4 and the bushing 35 so that the concentricity of both the feed sleeve 28 and the spacer 26 will be maintained. The circumferential surface of the outer end of the sleeve 28 is knurled, as shown in Fig. 1, so that the axial adjustment of the spacer 26 may be made by hand rotation thereof or by rotation with the aid of a pin (not shown) inserted in an opening 28.

A rotational movement is transmitted to the hub assembly through the girth gear 21 by a meshing pinion 38 on a jack shaft 40. The jack shaft is rotatably mounted in a bearing sleeve 4I of bronze or the like, inserted in an opening through the frame I1 and spaced at one side of the spindle I4 so that the axis of the jack shaft is parallel to the axis of the spindle. The bearing sleeve 4I is open on its. side adjacent the spindle from a position intermediate its height to the bottom thereof, to permit gear and pinion engagement throughout the axial length of hub I5 adjustment. The open portion of the sleeve 4I as shown has an angular extent of approximately The upper end of the jack shaft is formed with a square cross-section to fit a corresponding wrench (not shown), used in the manual rotation of the tool. Alternately a slow speed air motor or other mechanical or electrical device may be used to transmit rotational force thereto.

As shown in Fig. 3, the pinion 38 which is essentially the same diameter as the shaft 40 is provided with a threaded neck for attachment in a correspondingly threaded cavity in the lower end of the shaft 46, and a washer 42 is attached to the lower end of the pinion by a screw 43. The outside diameter of the washer 42 is slightly less than either the pinion or shaft. The difference in diameter need be only a few hundredths of an inch, so as to provide rotational clearance between the washer and the bearing sleeve 4I. Thus, when the teeth of the gear 21 and pinion 38 are in operative engagement the teeth of the gear are overlapped on top and bottom by the end of the shaft 40 and the washer 42 so that the gear and pinion will remain in mesh regardless of the axial position of the spacer 26 on the spindle I4 and the shaft 40 cannot be withdrawn throughvthe bearing sleeve 4I.

Referring particularly to Figs. 3 and 4, the plunger 3! is of rectangular cross-sectional shape having a rounded end 44 and with its sides, top and bottom finished to close tolerances for a snug, sliding fit in the socket 36'. Since the bearing sleeve 34 extends through the central portion of the socket 30, the plunger 3I is provided with a longitudinally elongated opening 45 therethrough which determines the limits of radial movement of the plunger 3! by the clearance between the walls of the opening and the sleeve 34. The rounded end 44 of the plunger is provided with a recess 46 of square cross-section for the support of the cutting tool I6 which is held therein by a laterally extending set screw 41. The recess 46 is located in the plunger so that the cutting edge of the tool inserted therein will be located along the longitudinal centerline of the plunger and .perpendicular to the axis of rotation of the tool I6 about the spindle I4. A transverse slot 48 is located immediately above the recess 46 in the annonce s end. of the plunger for lthe installation of *ay roller 51T. Thel roller 50' is rotatabley about a vertically positioned pin which is so, spaced along the longitudinal axis of the plunger with regard to the end 44' thatl ya .segment of the roller projects beyond the plunger 31. While the'y projection :oi a segment of the roller beyond the end of the plunger is xed at all times, vthe extent of the projection of the cutting tool 16. beyond", `the plunger may be altered as required to. regulate the Width of the cutof that tool `ori 'the seat .l0 voi the handhole. The opposite end. of .the plunger 3l, within kthe socket 3U, is provided Withan aperture 52 'connecting the elongated opening l5 sur'- rounding the spindle I4 with the: socket 3.0.

A duid under pressure, for example, com pressed air, `is delivered tothe socket 30a through a series: of internal passageways as shown Figs. l2, 3', 4, and 5. Compressed air is delivered to the apparatusthrough `a 'flexible hose or the like (not shovvn'l which. is connected tol an opening'155 in one side of' the Vframe l1 adjacent the spindle. This opening extends through the wall of the frame 11 Vand is in communication with an annular 'groove 56 in the surface of the spindle from which a diametrical hole 5T leads to an axial bore f5.8 therein. Above Ythe level of the hole 51, the bore "58 isv cut'to a larger diameter, threaded and thenv sealed byv a flat pointed set screw lill.

The `axial bore 58 extends approximately to the. midpoint of the, `spindle and at this point a diarnetricalv hole 5,2` connects the bore 58 with a pair oflongitudinalgrooves 63 in the outer surface oi' 'theSpindLe These grooves 63 are parallel to the axis of the spindle and extend a distance subu stantially equal rto the extent of axial adjustment of the spacer 26 yon the spindle |14. A vertically spaced ,pai-r of annular grooves 64 in the internal surface of the sleeve 34 vare each. provided with apair of radially drilled holes 65 and B5 through the vta-lief the sleeve leading respectively to the elongated opening 45 in -the plunger .3i and to the upper portion of the 4spacer l2li above the partition 33. Thus., regardless of the axial position of the spacer relative to the spindle. I4, compressed air will. .be delivered to the elongated opening 45, and the passage of. the air through the aperture v5.2. into the Vrear of the socket 30 Will force the plunger radially outward.

When the spacer 2'6 in a proper position relative to the handhole opening li and the seat le, the action o the. compressed .air in forcing the yplunger outward will bring 'the roller 5U in contact with the Wall' f2 and the tool lli .in Contact with the seat I0. 'The compressed air lacting on the plunger 3l will cause it to slide outwardly in the 'socket 38' maintaining the roller dll in contact with the Wall -l2, and as the hub i5 is ro- 'tated'ahout'the .spindle I4 the roller follows the contour or" 'the .handhole wall correspondingly changing the radius arm 'of the tool,v i6. `slight leakage of compressed air between the walls o1" the plunger 3l and the lsocket 30 `will advantageousl'y prevent the deposition of metal chips therebetween from the ln'iachining ope-ration. This will 4avoid scoring and undue yWear on those surfaces.

In .the linstallation of the apparatus edsc-ribed, the 'plunger Si :with its associated roller 50 `and cutting tool ILE is retracted into the socket 35i .and the Aclamp t8 'is yadjusted to 'a position on the inner end 24 Io'i the spindle M. The apparatus may then Ahe 'tipped to one side and the clamp and spindle inserted in the handhole "Il, With the frame I7 resting on the exterior surface of the 'ovaliy 'i2'4 and the spindle i4' projecting: through the handhole in its desired axial position, Athe clamp may be drawn .into tight contact with the inner surface of the handhole WallV by turning the spindle. Thus the Aspindle is rigidly positioned relative to the handhole seat with the seat refacing tool desirably mounted between the Spindle end supports. Thereafter a preliminary axial: adjustment oi the spacer r2t is made to assure con tact of the roller ilfupcn the wall l2 of the hand hole when the plunger 3l is radially extended vby the application of compressed air thereto. It is of rcourse understood that the preliminary adjustment of the level oi the plunger 3l so that the rollerv 5% will be in contact with the handhole Wall when radially extended must necessarily position the tool it so that it will project into the `annular recess in the handhole wall be'. neath the seat Iii. The cutting tool H5 may then be brought into a cutting contact position` with the seat lil by axial adjustment of the spacer 26', and as the tool is rotated by turning the jack shaft 4i), the depth of cut on the surface of the seat is regulated by further adjustment with the feed sleeve 23.

After completing `the seat refacing operation, the tool assembly is removed from the handhole by releasing the compressed air pressure, relieving the holding pressure of the clamp I8 hyunscrevving the spindle i4 and tipping the assembly for Withdrawal through the handhole opening. With the removal of the compressed air pres sure on the `plunger 3i, the plunger is free to move in its socket Sii and it may be manually retracted so that the projection of the tool' I6 beyond the body of the spacer 2li is at a minimum, thereby facilitating the removal of the apparatus from the handhole.

It will be observed that the retractability of the cutting tool assembly within the hubv of the apparatus contributes materially to the iacility of installation and removal thereof prior and subsequent to the machining operation. The use of a pressure fluid land ra guide roller to radially position the cutting tool so as to follow the contour of the handhole advantageously provides a substantially uniform application of radial `pressure thereon and assures an accurately machined seat. Furthermore, since the tool assembly of the present invention is completely supported in the one handhole and all :adjustments of the tool and tool assembly may be accomplished either through that handv hole or externally of the header, itis notnecessary to support the .tool assembly from an adjacent handhole or handhole fitting, orto open an adjacent handhole for access to the inner end of the tool assembly.

Whiley in accordance with vthe provisions ofthe statutes We have illustrated and described `herein the best forms of our invention now `known to us, those skilled lin the art will understand that changes may be made in the form of the apparatus disclosed without departing from the spirit of the invention covered by our claims, and that certain features of our invention may sometimes be used. to advantage Without a corresponding use of other features.

We claim:

1. A tool assembly for machining .an `internal closure seat for a pressure vessel wall opening comprising a spindle arranged to project 'through said pressure vessel Wall opening, means vfor supporting said spindle normal to the plane of the closure vseat and substantially centered with respect to the wall of said opening, a spacer journaled for rotation about said spindle, a radially slidable tool holder mounted Within said spacer,`

av metal cutting tool and a roller mounted in spaced relationship in said holder and arranged to project radially beyond one end of said holder, means for rotating said spacer about said spindle, means for adjusting the position of said spacer axially of said spindle, and means for pneumatically adjusting said holder radially of said spindle with said roller in guiding lcontact with the boundary wall of said pressure vessel opening.

2. A tool assembly for machining an internal closure vseat for a pressure vessel Wall opening comprising a non-rotative spindle arranged to project through said opening normal to the plane of said seat, means providing a rigid support for said spindle on opposite sides of said handhole wall, a spacer arranged for rotation upon said spindle, a threaded sleeve rotatable With and engaging correspondi'nug threads within said spacer, a thrust bearing arranged to position said sleeve relative to said spindle and to permit axial adjustment of the spacer on said spindle, a plunger slidably fitted Within a radial open ended socket in said spacer, said plunger having an elongated opening therethrough loosely encircling a portion of said spindle, a cutting tool mounted Within a receptacle of said plunger and arranged to project beyond the end thereof, a guide roller mounted in a recess of said plunger arranged to project beyond the end of said plunger and in inwardly radial spaced relationship with said cutting tool, means responsive to a fluid pressure for holding said guide roller in contact with the internal configuration of said Wall opening, and means for rotating said spacer.

3. A tool assembly for machining an internal closure seat for a pressure vessel Wall opening comprising a non-rotative spindle arranged to project through said Wall opening normal to the plane of said seat, means providing a rigid support for said spindle on opposite sides of said handhole wall, a spacer arranged for rotation upon said spindle, a threaded sleeve rotatable with and engaging corresponding threads within said spacer, a thrust bearing arranged to position said sleeve relative to said spindle, a plunger slidably fitted within a radial open ended socket in the bottom portion of said spacer, said plunger having an elongated opening therethrough loosely encircling a portion of said spindle, a cutting tool mounted within said plunger and arranged to project beyond the end thereof, a

guide roller mounted in a recess of said plunger arranged to project beyond the end of said plunger and in inwardly radial spaced relationship with said cutting tool, means associated with said spindle and said spacer for transmitting a gaseous fluid pressure to said socket for urging said plunger radially outward for contact between said roller and. the Wall of said pressure Vessel opening, and means for rotating said spacer.

4. A tool assembly for machining an internal closure seat for a pressure vessel wall opening comprising a frame arranged to'exteriorly straddie said Wall opening, a spindle threaded at both ends arranged to project through said opening and said frame in a direction normal to said closure seat, a lock nut threaded to the exterior end of said spindle and arranged to position the end of the spindle relative to said frame, a clamp 8f: arranged to interiorly straddle said wall'opening and threaded upon the interior end of said spindle, a spacer arranged for .rotation upon said spindle, a threaded sleeve rotatable with and engaging threads within said spacer, a thrust bearing arrangedto iix theaxial position of said sleeve relative to said spindle, a radially slidable plunger within said spacer, a cutting tool and a roller in spaced relation vtherewith secured to said plunger and arranged to project radially normal to and beyond the cylindrical Wall of said spacer, means for rotating said spacer and said sleeve about said spindle, and means for radially adjusting said plunger with its cutting tool into contact with said seat. y v I 5; A tool assembly for machining an internal closure seat for a pressure vessel wall opening comprising a frame arranged to exteriorly straddle said wall opening, a spindle threaded at both ends arranged to project through said opening and said frame in a direction normal to the clo-v sure seat and substantially centered With respect to the Wall opening, a lock nut threaded to the exterior end of said spindle and arranged to position the end of the spindle relative to said frame, a clamp arranged to interiorly straddle said wall opening and threaded upon said spindle, a hub arranged for rotation upon said spindle, a threaded sleeve rotatable with and engaging corresponding threads within said khub, a thrust bearing arranged to fix the position of said sleeve relative to said spindle, a plunger slidably tted within a radial open ended socket in the bottom portion of said hub, a cutting tool mounted within said plunger and arranged to project beyond the end thereof in a plane parallel to the plane of the closure seat, a guide roller mounted in a recess of said plunger in radially spaced relationship with said cutting tool, means associated with said spindle and said hub for transmitting a uid pressure to said socket urging said plunger radially outward for engaging contact between said roller and the Wall of said pressure vessel opening, and means for rotating said hub.

6. A tool assembly for machining an internal closure seat for a pressure vessel wall opening comprising a spindle arranged to project through said opening, a frame arranged to support said spindle normal to the plane of the closure seat and centrally located with respect to the wall opening, a generally cylindrical spacer arranged nfor rotation on said spindle and having a bearing sleeve aixed thereto encircling said spindle, ,a cylindrical threaded sleeve in xed axial position relative to said spindle rotatable with and engaging corresponding threads internally of` said spacer, a radially slidable plunger within said spacer, a cutting tool and a roller in spaced relation therewith lsecured to said plunger and arranged to project radially normal to and beyond the cylindrical Wall of said spacer, means for rotating said spacer about said spindle, and means for radially adjusting said plunger With its cutting tool in contact with said seat including an axial bore extending longitudinally of said spindle from a radial opening adjacent the outer end of said spindle and communicating with a source of compressed air vto a radial opening intermediate .the length of said spindle, a longitudinal groove in the surface of said spindle extending inwardly from said intermediate opening, and internal circumferential grooves on said bearing sleeve having radial openings leading from said grooves to a recess behind said plungerin said spacer.

7. A tool assembly according to claim 1 wherein said means for supporting said spindle comprises a frame exteriorly straddling said Wall opening and embracing the exterior end of said spindle, and a clamp having arms stradding the interior of said Wall opening and threaded upon the interior portion of said spindle.

PAUL REKETTYE. CARL A. MAXWELL.

REFERENCES CITED The following references are of record in th file of this patent:

UNITED STATES PATENTS Number Name Date 638,712 Higgins Dec. 12, 1899 1,953,402 Graham Apr. 3, 1934 10 2,039,719 Kline et al. May 5, 1936

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