US1325278A - A corpora - Google Patents

Description

F. A. AND B. P. DEXTER.

FAClNG TOOL FOR DRESSING VALVE SEATS, m.

APPLICATION FILED JAN2, 1919. 1,325,278.

Patented Dec. 16,1919.

3 SHEETSSHEET 1 F. A. AND B, P. DEXTER. FACING TOOL FOR DRESSING VALVE SEATS, &c.

APPLICATION FILED JAN-2, I919.

Patented Dec. 16,1919.

3SHEET$SHEET 2- Merzfimy F. A. AND B. P. DEXTER.

FACING IOOL FOR onessma VALVE SEATS, ac.

APPLICATION FILED JAN. 2, 1919.

1,325,278. Patented Dec. 16,1919.

3 SHEETS-SHEET 3- WZO/(OACQI STATS ATENT UFFlCE.

FRED A. DEXTER AND BAYARD 1?. DEXTER, 0E ORANGE, MASSACHUSETTS, ASSIGNORS TO THE LEAVITT MACI-ZENE COMPANY, SF ORANGE, MASSACHUSETTS, A CORPORA- TION OF MASSAGIESU'EFETTS.

FACING-TOOL FOR DRESSING- VALV E-SEATS, 8w.

Application filed January 2, 1919.

To all whom 2'2? may concern:

Be it known that we, FRED A. DEXTER and BAYARD P. DEXTER, citizens of the United States, residing at Orange, county of Franklin, State of Massachusetts, have invented certain new and useful Improvements in Facing-Tools for Dressing Valve-Seats, &c.; and we do hereby declare the following to be a full clear, and exact description of the invent-ion, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a tool for dressing valve seats and the like, and more especially to a tool adapted for re-cutting such elements that have become worn or pitted in use, so as to provide a uniform fluid tight contact between the valve and the seat or seats. The object of the invention is to provide a compact, strong, substantial and efficient tool adapted to operate on valves of various sizes and characters, either while the valves are in position on the pipe line, or in certain cases when the valves have been disconnected from the line. To these ends, the invention comprises a frame provided with a plurality of oppositely movable and adjustable holding elements, preferably constituted by slides mounted for reciprocatory movement in the frame and carrying lugs adapted to be engaged with either the inside or outside of the valve casing to clamp the frame thereto, said frame being provided with means for adjusting the slides to clamping position, said means preferably being in the form of a rotatable shaft having right and left screw threads thereon engaging corresponding threaded portions of the respective slides, a hollow standard mounted on one face of the frame and carrying a reciprocatory and rotatory spindle adapted to be engaged with a cutter or facing tool which operates on the valve seat to be refaced, said spindle being associated with a feed screw, in the form of a hollow sleeve having exterior threads which engage an interior thread on the upper part of the standard, which latter is provided with a special form of means for locking and unlocking the feed screw, so that the latter may be actuated to feed the spindle forward during the effective operation of the cutting tool.

Specification of Letters Patent.

Patented Dec. 16, 1919.

Serial No. 269,383.

Fig. 3 is a vertical longitudinal section through the apparatus as applied to an ordinary globe valve.

Fig. 4: is an elevation, partly in section, of the tool as applied for facing the seat of a sliding gate valve.

Fig. 5 is a detail of the attachment for connecting the spindle and'the facing tool as shown in Fig. 4.

Many types of valve seat re-facing or dressing tools have been heretofore suggested and employed, but, so far as applicants are advised, these tools of the prior art have been'limited in their application to valves of certain definite types and substantially uniform sizes so that special tools must be provided for operating upon valves of different types, anddiflferent sized tools must be constructed for varying sizes of valves of the same type. The present invention, however, is designed to present in a single instrumentality a form of tool which is not only capable of ready and efficient application to valves of the different standard types, such as various forms of globe valves and the many modifications of sliding gate valves, but also to various sizes of valves of the same'general type. For example, in the drawings, the tool is exemplified in two of its modes of effective application, that represented in Fig. 3, illustrating it applied to an ordinary fiatseated globe valve and that shown in Fig. l representing the tool applied to a slidingvgate valve. The application of the tool to other forms of valves will be obvious to those skilled in the art.

Referring to Figs. 1 to 3 of the drawings, the base of the tool comprises a generally rectangular frame having longitudinal mem- 1, 2 and permit said slides to be moved longitudinally of the frame.

Projecting from the under face of the slides 5 and 6 are lugs 7 and 8 respectively, one of which lugs, as 7, is provided with a convex outer lateral surface and a concave inner lateral surface, both of said surfaces being scored or grooved to provide grippin surfaces for either the inner or outer wall or a valve casing. The other lug or jaw S is provided with two convex outer faces and two concave inner faces, all of which faces are scored or grooved similarly as the faces of lug or jaw 7. The lugs or jaws as thus constituted are therefore adapted to engage the inner or outer surface of the valve casing adjacent one of the openings in the easing, and thereby lock the frame securely to the casing and center the frame with respect to the valve seat to be ground or dressed. The automatic centering of the frame and therefore of the tool with respect to the valve seat is facilitated by the three-point contact between the engaging faces of the lugs 7 and 8 and the valve casing, whether said contact be made exteriorly or interiorly of the valve casing. In Fig. 3, the jaws 7 and 8 are shown engaged with the interior of the valve casing,.but fora smaller valve casing the same effect would be produced by engaging the lugs with the exterior walls of the valve casing, as will be apparent.

In order to move the slides 5 and 6 simultaneously and to the same extent in opposite directions to effect the clamping of the frame to the valve casing, there is journaled in the end members 3 and 4: of the frame a shaft 9 provided with right and left-hand screw threads respectively extending from the middle toward the ends which screw threads engage correspondingly threaded openings in the slides 5 and 6, so that when the shaft 9 is turned in one direction or the other by means of the hand wheel 10, the slides 5 and 6 are moved toward or away from each other and into gripping engagement with the valve casing as described. The shaft 9 is locked against longitudinal movement by means of a set collar 12 and the hand wheel 10 is locked to said shaft by means of a suitable nut 11.

Mounted on the outer face of the frame and secured to the side members 1 and 2 thereof is a standard comprising a square base member 13 fastened to the frame by bolts 14:, from which base rises a hollow standard 15, the upper portion of which is provided with a tapered eXteriorly screwthreaded portion 16 divided into sectors by a cross kerf 17. The lower portion of said spindle is provided with a longitudinal bearing in which the tool spindle 20 rotates.

Said tool spindle 20, which is journaled in the standard 15 has its upper portion reduced to take the inner bore of a hollow feed screw or sleeve 25, the exterior screw threads of which engage the inner threaded neck of the standard 21. The spindle 20 and the feed screw 25 are each provided with hand wheels 22 and 26 respectively to rotate the corresponding members. The longitudinal axis of the spindle 20 is normal to the plane of the frame, and the spindle is located midway between the slides 5 and 6 and is therefore centered with respect to the lugs 7 and 8 for all relative positions of the latter. The spindle 20 is freely rotatable in its bearings in the standard 15 and the feed sleeve 25 respectively, and is moved transversely through the frame in either direction by means of the feed screw 25, when the hand wheel 26 thereof is rotated, by reason of the engagement of the exterior screw threads on the sleeve 25 and the interior threads on the upper end of the standard 15.

in order to lock the feed screw against rotatory movement, the split, tapered and threaded upper end of the standard 15 is engaged by a clamping collar 18 which when turned up on the screw threads 16 of the standard compresses the sectional end portions of the standard and causes them to firmly grip the feed screw 25 and prevent rotation of the latter. When it is desired to operate the feed screw either to feed the spindle forward or to retract the latter, the nut 18 is backed off a sufiicient distance to permit the sectional ends of the standard 15 to move outward and relieve the clamping action between the same and the feed screw 25.

The end of the spindle 20 is provided with a screw-threaded projection 23, which in this particular embodiment of the invention is adapted to engage a central opening in a disk-like cutting or dressing tool 24, the lower face of which engages the valve seat ll to re-surface the same when the spindle 20 is rotated, the depth .of the cut produced by the facing tool being regulated by means of the feed screw 25 which advances the spindle and the cutting tool toward the work. After a sufficient amount of the metal in the valve seat has been removed to restore the uniform surface of the seat. the feed screw is locked to the standard by setting up the nut 18, after which the spindle and its associated cutting tool 24: may be rotated to efiect a smooth, even finish of the valve seat.

The mode of applying the tool to a globe valve is shown in Fig. 3. The cap or bonnet of the valve having been removed, the supporting frame of the tool is laid on top of the valve casing and the slides 5 and 6 adjusted by means of the screw shaft 9 so that the lugs 7 and S are brought into gripping engagement with the inner screw threaded surface of the opening in the valve casing. The three-point bearing between the lugs 7 and 8 and the inner walls of the valve casing insures an accurate centering of the spindle 20 with respect to the valve seat, and as the latter is parallel with the upper marginal edges of the opening in the valve casing, the tool 24 is presented in parallelism with the valve seat, so that, when said tool is fed forward into contact with the seat by means of the feed screw 25, which advances the spindle 20, a few turns of the spindle 20 by means of hand wheel 22 will accurately dress and re-surface the valve seat.

Should the opening in the valve casing be too small to conveniently receive the lugs or aws 7 and 8 inside said opening, in order to properly mount and clamp the tool to the valve casing, it is only necessary to adjust the slides 5 and 6 so that the lugs 7 and 8 will lie outside of the walls surrounding the opening in the valve casing, after which the shaft 9 is rotated to bring the inner faces of the jaws 7 and 8 into engagement with the outer walls of the valve casing, thereby locking the frame and the appurtenant parts of the tool to the valve casing. It will thus be seen that a single tool of the type described, will accommodate valves of many different sizes and that by merely adjusting the slides 5 and 6 and the clamping jaws 7 and 8 carried thereby, the tool may be accurately and firmly clamped in proper position on any valve casing within the limits of adjustment of the slides.

Fig. 4 of the drawing shows the tool as applied to dressing one of the seats of a sliding gate valve. In operating upon this type of valve, it is necessary to remove the entire valve from the pipe line and to separate the valve proper and its hood from the casing, whereas in applying the tool to a globe valve or valve of similar type, as shown in the preceding figures, it is not necessary to remove the valve from the pipe line or other connection inasmuch as the tool may be applied to the valve casing in situ.

In applying the tool to a sliding gate valve, the base frame of the tool is secured to one of the fluid passages of the valve casing by engaging the clamping lugs 7 and 8 either exteriorly or interiorly of the portion of the valve casing surrounding such opening. As shown, the base frame is clamped to the casing by the lugs 7 and 8 engaging the interior walls of the opening, opposite that in which the seat which is to be dressed is located, so that the spindle 20 of the tool is in axial alinement with the inlet and outlet openings of the valve casing.

For dressing the seats of gate valves, a special dressing or cutting tool is employed, preferably of the type shown in patent to Williams 8: Smith, No. 1,227,514, dated May 22, 1917, which comprises a rotary disk or cutter head 50, provided with a series of cutters 51 on one face thereof, said cutter having associated therewith a handle 52 adapted to be operatively connected with the disk by means of a pawl and ratchet friction band or similar means, whereby oscillation of the handle will produce a step by step rotary motion of the cutter head, thereby causing the cutters to resurface the face of the valve seat ring with which the cutter is engaged. This cutting tool is passed into the valve casing through the upper opening thereon, after the bonnet and valve have been removed, and is properly centered to bring the cutters into engagement with the valve seat by means of an extension head 20, which is screwed on to the end of the spindle 20, said extension head having a rounded end which engages a central opening or depression 53 in the cutter head 50.

As illustrated in Fig. 4c, the frame of the tool is secured to one end of the valve casing, in the opening opposite that in which the seat to be ground is located. The cutter head is then passed through the upper opening in the valve casing and the feed screw 25 operated to advance the spindle until the end of the extension piece 20' engages the central opening 53 in the cutter head and forces the cutters 51 into contact with the face of the valve seat ring. The cutter head 50 is thereby brought into parallelism with the face of the valve seat ring, so that when rotary motion is imparted to the cutter head, the cutters will accurately trim the face of the seat ring, the depth of the out being determined by the feed screw 25, as will be understood. After one of the seat rings has been ground, the cutting tool is reversed and applied to the opposite end of the valve, in the same manner to permit the other seat to be dressed. v

From the foregoing, it will be apparent that theinvention is capahle of general application to valves of various types and sizes, and constitutes a simple, durable mechanism, capable of being quickly adjusted and ofiering no delicately constructed or connected parts to become deranged or broken, so that a single apparatus of the character described involving a reasonable number of cutting elements of the particular types shown, will serve the purpose of a large number of units of varying sizes of the types as heretofore employed for dressing valve seats.

What we claim is 1. A tool of the class described, comprising a frame, a single pair of slides mounted for movement in opposite directions on said frame, means for moving said slides, means on the slides for engaging the interior or exterior of the valve casing at three points arranged in triangular relation, and means supported by said frame for engagement with a dressing tool,

2. A tool of the class described, comprising a frame, a pair of slides mounted in said frame for movement in the opposite directions, means for moving said slides, means projecting from the slides for engaging the interior or exterior of a valve casing at three points arranged in triangular relation, and a tool spindle supported by said frame.

3. A tool of the class described, comprising a rectangular frame, a pair of slides mounted on said frame for movement in opposite directions, lugs on the slides for engaging the interior or exterior of a valve casing at three points arranged in triangular relation, a standard carried by said 15 frame, a spindle mounted in the standard and extended through the frame intermediate said slides for engagement with a dressing tool, and an oppositely threaded shaft engaged with the slides between the 20 FRED A. DEXTER. BAYARD P. DEXTER.

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