US2988859A

US2988859A - Expansible honing tool head

Info

Publication number: US2988859A
Application number: US801596A
Authority: US
Inventors: Chaffey Stephen James
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-01-27
Filing date: 1959-03-24
Publication date: 1961-06-20
Anticipated expiration: 1978-06-20
Also published as: DE1134913B; CH365628A; GB873133A; FR1287629A

Description

June 20, 1961 S. J. CHAFFEY EXPANSIBLE HONING TOOL HEAD Filed March 24, 1959 M prroewav,

United States Patent 2,988,859 i EXPANSIBLE HONING TOOL HEAD Stephen J'ames Chalfey, 7 Reay Nadin Drive; I

" Sutton 'Coldfield, England Filed Mar. 24, 1959, Ser. No. 801,596

2 Claims. (Cl..51184.1)

This invention relates to honing and polishing apparatus for. operating on the bores of tubes and the like.

Honing and polishing apparatus heretofore employed comprises a hollow body supported on the end of a tubular spindle through which pressure fluid is fed to the body the walls of-which are formed with a plurality of radial.

openings'in which cutting elements are slidably disposed in the manner of pistons and are urged radially outwardly by the pressure fluid into cutting or abrasive contact with the bore of a tube to be honed or polished andthe body and'tube are relatively rotated and reciprocated to eflect the honing or cutting action. I t

In some operations fast stock removal from the tube is required .for example 0.006 or more'inches in diameter per foot length of the tube perminute and in order to attempt to accomplish this removal it has been found necessary to use high fluid pressures of for example 120 lbs.

per square inch. In an attempt to prevent loss of pressure and the fluid flat sealshave been proposed the edges of which .make contact with the openings but dueto the high fluid pressures employed and wear on the. sides of the openings due to the movement of cutting elements therein a substantial leakage occurs between the edges of the flat seals and the sides of the openings so that the rate of stock removal is considerably decreased and is less than required. Increasing the fluid pressure to increase the rate of stock removal further increases the.

leakage and therefore does not solve the problem. It is found that the bores of some tubes to be operated upon are tapered and/or oval and in some cases bent slightly out of the straight and when such bores are being operated upon the cutting elements and seals become pitched orj'tipped correspondingly about longitudinal and/or.

transverse axes and this allows further pressure fluid leakage to occur between the seals and openings.

2 The body 10 of the honing apparatus is somewhat cylmdrically formed and is elongated in the direction of its longitudinal central axis. At one end the body is provided with a screw-threaded bore 11 into which is screwed the screw-threaded end portion 12 of an adaptor or attachment 13 until a collar 14 abuts the end face 15 of the body so that the adaptor can be locked to the body. The adaptor 13 is also formed with another screw-threaded end portion 16 which is adapted to be screwed into the i one end of a hollow tubular spindle 17 adapted at its. other end to be secured .to a driving means such as a tapered shank.

The adaptor or attachment 13 and the spindle 17 are herein referred to as a hollow mernber in connection with a valve 18 to be hereinafter described and the screw connection between the hollow member and the body 10 enables said body to be removed from the hollow member for maintenance purposes.

The valve 1 8 comprises an annular piston 19 which isv slidably housed in a cylindrical chamber 20 formed in the The piston 19 comprises a backing hollow member. portion 21 made ofmetal having a head and a skirt 22 extending rearwardly from the head i.e. towards the adaptor 13. The head is formed with a central screwthreaded bore into which isscrewed a screw-threaded shank of a seat member 23 and between the outer face of the head and a clamping face-formed by an outwardly directed flange of the seat member there is clamped an annular flexible sealing member 24 which is of cup shape to provide a skirt 25 making sealing engagement with the cylindrical wall of the chamber 20 and the skirt extends forwardly i.e. in a direction away from the adaptor 13 so as to face the direction of flow of pressure fluid introduced into the spindle 17 at a position adjacent the end of the spindle remote from the valve 18.

Extending through the seat member 23 i.e. through the flange and shank thereof is a central duct 26 which is coaxial with the axis of the spindle and chamber and the forward end of the duct i.e. the end opening at the flange of the seat member constitutes an annular seat for the valve head 27 of a mushroom-type valve member the stern For maintenance or other purpose it is oftennecessary to remove the hollow body from the spindle and heretofore the pressure fluid in the spindle has run to waste even though the pressure fluid supply has been terminated by ,a suitable control. valve... Furthermore, at the instant of removal of the body from the spindle the fluid, usually an oil, runs over the operators hands and also becomes mixed with the cutting liquid used as a coolant and lubricant for the honing operation and if this, coolant liquid is not the same as the pressure ing occurs.

fluid undesirable intermix- 'It is an object of the present invention to provide hon'- ing or polishing apparatus which avoids the loss of a substantial quantity of pressure fluid and particularly when the body is removed from the spindle.

Various other objects and advantages ofthe invention will become more fully apparent from the following specification, appended claims and accompanying drawings wherein:

FIGURE 1 is aiperspective view of one far of honing ori polishing apparatus.

FIGURE 2' is alongitudinal sectional viewof the honing apparatus but on a larger scale.

FIGURE 3 is. a view similar to FIG. 2 but showing only a part thereof and witha valve in a different I position from the position shown in FIG. 2.

FIGURE 4 is a cross-sectional plan view of FIG. 2 on Q the lines 44 thereof and' 28 of which extends through the duct and at its rearward end 29 is slidably guided in an axial direction in a hole 30 extending axially through the adaptor 13 so as to maintain the valve head co-axial with the seat.

The valve head 27 is normally urged into a closed position in engagement with the seating (as shown in FIG.

2) by ahelical compression spring 31 which surrounds A further compression spring 34 which is conveniently referred to as the piston spring, is in the form of a helical spring which surrounds the stem 28 of the valve member and is of larger diameter than the valve spring 31 and is stronger than said valve spring and at its ends the piston spring is located in cylindrical recesses formed in the for- I ward end of the adaptor 13 and formed in the backing FIGURE -5 i's a fragmentary sectional view on a still largerscale showing a modification. I

portion of the above piston 19 by the head and skirt thereof and said piston spring 34 tends to urge the valve piston forwardly i.e. in a direction opposing the pressure fluid supply. L

Patented June 20, 1961 The enlarged diameter portion 33 of the valve stem is formed with a Hat rear face '35 which is adapted to abut i sure fluid can pass from the chamber 20 into a blindcavity 38 in the body said cavity 38 being open at. its forwardend i.e. that end adjacent the adaptor 13 and at its other end 39' being closed. The blind cavity 38 is of elongated formation longitudinally of the body and extends. for almost the full length thereof and said body at its end adjacent the closed end,39of.the cavity isformed.

with a hexagonal head 40 to facilitate screwing-of thebody 10, into and out of the adaptor 13.

Extending through the walls of the body in. directions radially thereof are four slots 41 which are equi-angularly spaced apart (as shown in FIG. 4) said slots communicating at their inner ends with the cavity 38. and at their outer ends opening onto the exterior 42 of the-body. The slots 41 are of elongated formation (as shown in the vanious figures) and their major axes extend in the direction of the longitudinal axis of the body and in length said slots extend for. the major part of the length of the body. The slots 41 are parallel sided and at their ends are semi-circular (as shown in FIG. 1).

In each of the four slots 41 there is housed a piston 43 which comprises a flat rigid head plate 44 made of metal and a cup member 45 made of flexible rubber or similar material and provided with a peripheral skirt 46' which is continuous around the piston. The cup member. 45 is secured to the underface of the plate 44 such as by bonding or an adhesive and said plate 44 and cup member 45 are each shaped so as to conform with the shape-of the slots 41 so that each piston 43 is of elongated formation and has round ends. Each piston is housed in a slot 41 with its skirt 46 directed inwardly towards the cavity 38 and the skirt 46 narrows in crosssection towards its free edge (as shown in FIG; 4) so that'the edge of the skirt is very flexible and forms an efficient seal with the slot.

Referring to FIGS. 2 to 4 in-each slot 41 there is disposed'a rigid holder or backing plate 47 which is coextensive with the head plate 44 of the piston so as to correspond in size and shape to the slots 41 and has a goodsliding fit engagement therewith and the inner face of a holder 47 is adapted'to abut against the outer face of the head plate 44 of a piston without however being secured thereto. Each holder 47 isformed on its outer face with a shallow groove 48 which extends longitudinally of the holder and terminates short of the semi-circular ends of the holder and in the groove in each holder: there is secured by a suitable adhesive an elongated cutting element 49 which is conveniently in the formof a .honing' stone. The cutting element 49 is of rectangular cross-section (as shown in FIG. 4) and is narrower than the holder 47 so as to fit Within the groove 48 and thusthe sides of the element 49 are not in contact with the sides of the slots 41 and therefore have no abrasive action thereon.

Each holder 47 is formed on both ends thereof on its exterior surface with a transverse groove 50' and the transverse grooves 50 are positioned beyond the ends of the cutting element 49 and are aligned with circumferential grooves 51 in and adjacent the ends of the body 10. In eachofthe grooves 51 there is located a split spring ring circlip 52 which lies in the transverse groove 50 in the holders 47 and exerts inwardly radial pressure thereon so as to urgethe cutting elements 49 radially inward with respect to the body 10 and into inoperative posi* tions.

In order to determine the inward radial movement of the pistons 43 and cutting element 49 under theinfluence of the split spring rings 52 the inner end of each.

slot 41 is formed with shoulders 53 on which the edges ofthe skirts 46'of the pistons can bear to determine the inward movement of the pistons.

Referring to FIG. 5 this construction of polishing apparatus is very similar to that disclosed in FIGS. 2 to 4 with the exception that a holder 47 is not employed for the cutting element and in this construction the'cutting element 47 abuts the outer face of the head place 44 of the piston without being secured thereto and the width of the cutting element 49is such as to enable said butting element to have a good sliding fit engagement with the sides of the slots 41. In order to obviate and diminish the abrasive action which the cutting element 49' has on the sides of the slots 41 said cutting elementmay be impregnated with a suitable lacquer.

The exterior 42 of the body 10 is conveniently provided with longitudinal flutes 54 disposed intermediate the slots 41 to permit of good circulation of the lubricant used during the polishing operation.

The pressure fluid employed may conveniently be a suitable oil or other liquid which may also in some instances be used as a lubricating and cooling liquid during the polishing operation.

Inuse when it is desired to polish or hone the bore of a tube the body 10 is inserted into the bore of the tube and the tube and body are relatively rotated and reciprocated, preferably the tube is held stationary and the body is rotated and reciprocated. The oil under pressure is then fed into the hollow spindle 17 where it passes to the end of the spindle adjacent the body 10 and operates on an annular valve piston formed by the

parts

19, 21, and 24 and on the valve head 27 so that the annular valve piston and valve member are urged rearwardly in the chamber 20 against the action of the piston spring 34. During this rearward movement of the piston. the valve head 27 remains on the valve seat so that the valve is closed until the enlarged diameter portion 32 on the valve stem abuts the end wall 36'of the adaptor thus preventing further rearward movement of" the valve member.

Rearward movement of the annular valve piston 19 continues, however, by reason of the fluid pressure exerted thereon so'that the valve seat moves away from thevalve head 27 to open the valve and permit the passages 37 in the adaptor into the blind cavity 38 in the ton into the chamber 20 and through the passage or passages 37 in the adaptor into the wind cavity 38 in the body 10. Rearward movement of the piston 19 can continue until the free edge of the skirt 2.2 abuts the forward end face of the adapter 13.

The pressure oil in the blind cavity 38 in the body '10 operates on the pistons 43 to urge them radially outwardly untilthe external surface of each of the cutting elements 49 bears on the bore of thetube to be polished and by reason of the relative movement of the cutting elements 49 to the tube the bore of the latter is honed or polished. The action of the pressure oil causes the skirts 46 of the pistons to be urged relatively apart into close fluid tight sealing contact with the sides 41 of the slots and in this way the pistons are rendered fluid tight in the slots. This has the advantage that very high fluid pressures in the region of, for example lbs. per inch may be employedwhereby an extremely fast honing or polishing;

action is obtained such as for example 0.006 inch per foot perv minute on a 4-inch bore diameter of tube and with any increase in pressure the fluid tight sealing of the pistons in the slots 41. increases. As before mentioned if the bore of the tube is tapered and/or oval and/or bent the cutting elements and pistons are pitched correspondingly but the provision of the skirts 46 ensures that fluid tight seahng contact is maintained by the skirts with the openings whereby pressure fluid loss is avoided. It is found in practice that the polishing apparatus according to-the present invention is capable of operating satisfactorily on bores withup to, 3% ovality and taper and a corresponding amount of bend withoutpressure' fluidloss occurring.

It will be appreciated that different honing and polishing operations require diflerent fluid pressures and these pressures.canbe varied in the body by means of the usual manually operated control valves employed in fluid supply systems and as the cavity 38 is a blind cavity the fluid pressure can be accurately controlled to obtain the required honing action.

When it is required to terminate a polishing operation the cutting elements 49 occupy positions in which they are partially withdrawn from the tube for the reason that the elements cannot be completely withdrawn as this would cause the end of the bore to become flared and might cause damage to the apparatus and when using apparatus according to the present invention, at this stage the rotation of the apparatus is stopped and the pressure of the fluid supplied to the spindle 17 is reduced or terminated whereupon the piston spring 34 moves the annular valve piston forwardly froma position shown in FIG. 3 to the position shown in FIG. 2 and the valve spring 31 moves the valve member into a position such that its head 27 engages the valve seat in the member 23 to close the duct 26. During this movement of the piston the fluid pressure in the cavity 38 decreases thereby creating a suction in the cavity 38 and causing the pistons 43 and cutting elements 49 to be withdrawn radially into the body 10 and out of contact with the bore of the tube whereupon the apparatus can be withdrawn completely from the tube whereby scoring and flaring of the end of the tube are avoided.

The forward open end of the body 10, Le. that end adjacent the adaptor 13, thus forms a common inlet and outlet for the pressure fluid.

In order to effect maintenance work on the body and parts carried thereby such as the cutting elements and pistons it is necessary or desirable to remove the body 10 from the adaptor 13. As before stated when the pressure of the fluid supply in the spindle is reduced or terminated the valve 18 adopts a closed position (as shown in FIG. 2) and therefore when the body 10 is removed from the adaptor a very small quantity of the fluid is lost corresponding to the amount of fluid in the chamber 20 and passages 37 and cavity 38 and this is a relatively small quantity when compared with the considerable quantity of fluid contained in the spindle which is sometimes of considerable length such as for example 20 feet long and the bore of the spindle may be approximately 2 inches in diameter.

What I claim is:

1. In honing apparatus for operating on the bores of tubes an elongated hollow body providing a blind cavity having a common inlet and outlet for pressure fluid, a plurality of slots angularly spaced apart in the body and being of longitudinal formation and extending longitudinally of the body and each slot being radially disposed in the body and at its radially inner end communicating with the blind cavity and at its radially outer end opening onto the exterior of the hollow body, a plurality of elongated cutting elements supported in the slots and movable therein radially of the body into and out of cutting engagement with a tube, a plurality of pistons one inwardly of each of the cutting elements to move said cutting elements and each piston having a continuous peripheral skirt directed radially inwardly and engaging the walls of the slot to form an eifective seal preventing leakage of the pressure fluid operating on the radially inner end of the piston to urge said piston and thus a cutting element radially outwardly of the body, a hollow member detachably connected to the elongated hollow body and said hollow member providing a cylindrical chamber communicating with the common inlet and out let of the blind cavity in the body and through which cylindrical chamber the pressure fluid passes from a seat adjacent one end of the valve piston, a valve member cooperative-with the valve seat such that closing ,movement of the valve member occurs in the direction offlow of the pressure fluid to the blind cavity and also occurs-by movement of the valve piston in the reverse direction, spring means urging the valve member into its closed position with respect to the valve seat, cooperable stop means on the valve member and a relatively stationary part to determine movement of the valve member whilst the valve piston continues sliding movement so as to open the valve, and further spring means urging the valve piston in a direction opposing the flow of pressure fluid from the supply source and operative when the supply is discontinued to urge the valve piston in a direction such that the valve seat cooperates with the valve member whereby further movement of the valve piston and valve member in a unitary manner causes a suction eflect to be created in the blind cavity whereupon the cutting elements are drawn radially inwardly out of engagement with the bore of the tube in which they previously operated.

2. In honing apparatus for operating on the bores of tubes an elongated hollow body providing a blind cavity having a common inlet and outlet for pressure fluid, a plurality of slots angularly spaced apart in the body and being of longitudinal formation and extending longitudinally of the body and each slot being radially disposed in the body and at its radially inner end communicating with the blind cavity and at its radially outer end opening onto the exterior of the hollow body, a plurality of elongated cutting elements supported in the slots and movable therein radially of the body into and out of cutting engagement with a tube, a plurality of pistons one inwardly of each of the cutting elements to move said cutting elements and each piston having a continuous peripheral skirt directed radially inwardly and engaging the walls of the slot to form an eifective seal preventing leakage of the pressure fluid operating on the radially inner end of the piston to urge said piston and thus a cutting element radially outwardly of the body, a hollow member detachably connected to the elongated hollow body and said hollow member providing a cylindrical chamber communicating with the common inlet and outlet of the blind cavity in the body and through which cylindrical chamber the pressure fluid passes from a supply source to the blind cavity, an annular valve piston slidably mounted in the cylindrical chamber and providing a valve seat adjacent one end of the valve piston, a mushroom type vai-ve member having a head co-operative with the valve seat such that closing movement of the valve member occurs in the direction of flow of the pressure fluid to the blind cavity and also occurs by movement of the valve piston in the reverse direction and said valve member having a stem extending from the head and through a pressure fluid conveyor duct in the annular valve piston and slidably supported so as to maintain the head co-axial with the valve seat, a helical spring mounted around the stem and operative between said stem and the annular valve piston to urge the valve member into a closed position with respect to the valve seat, co-operative stop means on the valve member and a relatively stationary part to determine movement of the valve member whilst the valve piston continues sliding movement so as to open the valve, and further spring means urging the valve piston in a direction opposing the flow of pressure fluid from the supply source and operative when the supply is discontinued to urge the valve piston in a direction such that the valve seat co-operates with the valve member whereby further movement of the valve piston and valve member in a unitary manner causes a suction eifect to be created in the blind cavity whereupon the cutting elements are drawn 1 radially inwardly outof engagement with the bore=df thd 2,290,739 Chapman Ji1l'y12i1; 1942- tub'e on-which they previously operated. 1 2,342,599 Peterson FeB: 22;, 1944 V 242-2 296 Flder June 17; 1947 References Clted 1n the file of th1s patent 1 4 3 McMahan- Mar. 5 1 3' UNITED STATES PATENTS v 2472;049 sameck May 31, 1949 257,474 McKeon Sept. 30, 1941