US1227499A - Facing-tool for dressing valve-seats, &c. - Google Patents

Description

F. L. SMITH & T. B. WILLIAMS. FACING TOOL FOR DRESSING VALVE SEATS, &c.

APPLICATION FILED FEB. 11. I916.

Patented May 22, 1917.

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Patented May 22, 1917.

APPLICATION FILED FEB. H. 1916- F. L. SMITH & T. B. WILLIAMS. FACING TOOL FOR DRESSING VALVE SEATS, m.

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FRANK I4. SMITH, OF CHICAGO, ILLINOIS, AND THOMAS B. WILLIAMS, OF ORANGE, MASSACHUSETTS, ASSIGNORS TO THE LEAVITT MACHINE COMPANY, 0 ORANGE, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

FACING-TOOL FOR DRESSING VALVE-SEATS, 860.

Application filed February 11, 1916.

To all whom it may concern:

Be it known that we, FRANK L. SMITH and THOMAS B. WILLIAMs, citizens of the United States, and residents, respectively, of Chicago, in the county of Cook and State of Illinois, and Orange, in the county of Franklin and State of Massachusetts, have invented certain new and useful Improvements in Facing-Tools for Dressing Valve- Seats, &c., of which the following is a specification.

This invention relates to a facing tool for dressing valve seats, etc. and particularly to a tool adapted for recutting valveseats, etc. that have become worn or pitted as a result of long use, this class of tools being of a type especially adapted for attachment to a valve-casing and refacing a valve-seat in a pipe-line, or other location, in situ.

The present invention is an improvement upon those disclosed in our prior applications filed January 23, 1915, Serial Nos. 3897, 3898, and 3899 respectively. The prin cipal feature common to the tools of all of said three applications is a tool having two main parts, to wit, a cutter and a cutter-bar, in which the general direction of the tool is transverse to the cutting axis and which operates against or between two fixed resistance points or surfaces of the work or article to which the tool is attached. In all of said tools an important feature of the construction is a pivotal or universal connection between the aforesaid main parts, this connection permitting relative adjustment of said parts crosswise of the tool, and in addition adapting the tool, when the connection is a universal one, for operating upon valve-seats at an acute angle to each other. In the tools of all of said applications various important adjustments of parts for assuring the proper operation of the tool under many different conditions of use are provided for, and in the third of said applications provision is made for effecting said adjustments from the most convenient point, that is, from apoint outside the valve-casing in which the cutter is intended to Work, and preferably from the extreme outer end of the tool. The tool of Specification of Letters Patent.

Patented May 22;, 1917.

Serial No. 77,632.

the present application is one in which substantially all of these features are preferably retained.

The tool of the present application is how ever distinguished from those of the applications just mentioned in many respects. In the first place it is a tool in which a pivotal element carried by the cutter-bar is adjustable crosswise of said cutter-bar by means operable from a point outside a valvecasing. In the second place it is a tool in which the cutter-bar is attached to the valvecasing in a radically different manner from the tools of any of said prior applications. In the present tool the points of attachment of the cutter-bar to the valve-casing are near the working end of the tool and in or close to the cutting zone, a plurality of relatively movable parts on the cutter-bar and near the cutter being employed for engaging the interior of a valve-casing at different points and holding the cutter-bar to said casing. The preferred construction is one in which these elements for engaging the valve-casing bear a predetermined relation to the axis of the pivot element on the cutter-bar by means of which said cutter-bar is brought into proper working relation with the cutter and its support; and said movable elements for engaging and holding the valve-casing are preferably so constructed as to constitute elements of an eXpansible centering device, forming substantially an expansible chuck, for engaging the inner circular wall of a valve-ring. In the third place this centering device just described is preferably so constructed as to be capable of being set in different positions for cooperation with valve-rings either of large or of small diameter, and it also preferably has a considerable range of adjustment in each of said settings.

Various other features of our present in vention not hereinbefore referred to will be hereinafter described and claimed and are illustrated in the accompanying drawings in which:

Figure 1 is a sectional side elevation of a facing tool embodying our present invention in operative relation with a pair of valve-seats in a valve-casing.

Fig. 2 is an end elevation of the same, looking from the left in said view.

Figs. 3, 41- and 5 are enlarged views of the cutter-bar of said tool showing the same in side and edge elevations with the centering device expanded, said views being respectively an outer side elevation, an edge elevation and an inner side elevation of said cutter-bar.

Fig. 6 is a view similar to Fig. 3 showing the position of the parts with the centering device contracted.

Fig. 7 is a view showing in transverse section, taken in line 7-7 of Fig. 6, means for obtaining a quick and a slow adjustment of the main pivot and the centering device lengthwise of the cutter-bar.

Fig. 8 is a view similar to Fig. 6 of the lower part of the cutter-bar, showing the parts of the centering device set in a different adjustment.

Fig. 9 is a substantially central longitudinal section of a portion of the same, the section being taken crosswise of the plane of the centering device and its associated parts.

Figs. 10 and 11 are respectively an elevation and a central longitudinal section of a support for and the extension of the main pivot by means of which the cutter-bar is associated with the cutter.

Fig. 12 is a detail of said pivot.

Figs. 13 and 14 are respectively side and edge elevations of the main frame of the cutter-bar.

Figs. 15 and 16 are similar views of a cam slide for adjusting the main pivot of the cutter-bar transversely.

Figs. 17 and 18 are details showing opposite sides of the centering device with the elements thereof expanded substantially to their maximum diameter.

Fig. 19 is a detail of the lower end of a cam-lever for adjusting the centering device in any setting thereof.

Similar characters designate like parts in all the figures of the drawings.

Like the tools shown in the aforesaid applications our present tool is preferably one made up of two main parts connected by a pivotal or universal joint and is disposed in a general direction transverse to the axis of the cutter-bar and adapted for operation while in engagement with a plurality of resistance points or surfaces located outside the tool, that is lying in the work or its equivalent. Like said other tools this one is also one having comparatively thin main members in order that it may work in small spaces. The cutter is preferably, as in the aforesaid applications, a rotary cutter op-- erated by a ratchet-feed lever connected to the cutter in such a manner that this main element as a whole occupies as little space as possible in the direction of its thickness.

The two main elements of our present tool may be of any suitable construction coming within the foregoing disclosure. They are preferably a ratchet-feed cutter of any suitable type, such as A, and a cutter-bar, such as B. These two main elements will have a pivotal connection, usually a face-toface connection, as by means of a ball-and-socket joint, 23, for permitting ready connection and disconnection of these main elements by movement substantially in a straight line crosswise of the tool.

The element A comprises a lever, 1, a cutter proper, 0, and a ratchet-feed connection between said lever and cutter for converting oscillating movement of the lever about the cutting axis into a step-by-step rotation of the cutter proper. This cutter 0 preferably has a multiplicity of cutting blades or cutters proper, 0, as in the aforesaid applications, the specific features of said ratchetfeed cutter being set forth more fully in a separate application filed by us January 23, 1915, Serial No. 3900.

The main element B, is as before stated, a bar insertible down into the valve-casing C and adapted to form a support for the cutter. Usually the two main parts A and B will engage directly and work between resistance points or surfaces, such as those shown at a" and r, the relative separation of the two main parts serving to wedge them between these oppositely disposed resistance surfaces.

Suitable means must of course be employed for holding the two main elements A. and B in proper working relation when the tool is in use. That employed in the present differs greatly from the corresponding means of the aforesaid applications. Here, while the cutter-bar, as in said other tools, constitutes the principal means for locating the cutter in place, it is held in a direction lengthwise thereof in engagement with a plurality of points in the interior of the valve-casing C, this result being brought about by providing a cutter-bar having near the cutter a plurality of relatively movable elements for engaging the interior of said valve-casing. Preferably we provide a plurality of elements on the cutter-bar movable to different radial positions with respect to the axis of the main pivot element 2, the construction shown being one in which these relatively movable parts for engaging and holding the interior of the valvecasing constitute elements of a centering device, or expansible chuck, the holding elements or jaws of which engage the inner side of the annular valve-ring embodying the valve-seat 7" (or 1"). By merely extending the holding elements or jaws of this centering device or chuck the inner surface 10 or w of said valve-ring will be firmly gripped; and the centering device may be held in such posi tion in any suitable manner. The construction is also such that when wedged tightly in place the cutter-bar will be properly located crosswise as well as lengthwise.

In the specific construction illustrated the cutter-bar frame is made up of a pair of side rails, 66, connected by an upper crossbar, 7 and a lower connector, here shown as a disk, 8, with a central projecting bearing or hollow stud, 9. The interior of this hollow stud is intended to receive the pivot element 2 and also a combined bushing and operating slide controlling the transverse position of said pivot element and forming an extension of it. The exterior of said hollow stud is here intended to support an operating device for changing the adjustment of the holding members of the centering device or chuck.

The centering device is intended primarily as a means for assuring the maintenance of the axis of the pivot element 2 in its proper position in all adjustments, to adapt the tool for facing tools of different diameters. Its construction is preferably such that the holding elements or jaws there of will always move equal distances measured from the axis of the pivot element 2, in the adjustment from one diameter to another, and also in making the necessary fine adjustments for engaging a valve-ring of any given diameter after the centering device has been located approximately in position for cooperation therewith. Here both the pivot element and the centering device are carried by a common support, each being shown as in fixed relation, in the direction of said radial adjustment, to the hollow stud 9 at the lower end of the cutterbar frame. The centering device illustrated comprises a. supporting plate or ring, 10, and a circuit of holding elements in the form of short levers or jaws, 11 pivoted thereto. The supporting ring 10 is shown as mounted to turn on the outer bearing surface of the hollow stud 9 and as in contact at its inner face with the outer faces of the levers or jaws 11, which lie between the supporting ring 10 and the operating device be fore mentioned, which is preferably an operating cam-lever and rests against the outer face of the disk 8 of the cutter-bar frame. Each of the holding elements or jaws 11 is shown as connected to the ring 10 by a pivot-pin, 12, which extends outwardly but does not project in this case beyond the outer face of said ring 10. Normally the ring 10 is intended to be held in fixed relationwith the hollow stud 9, and hence with the cutter-bar frame. Any suitable means may be employed for this purpose. Here said ring, which is shown as mounted to move about the axis of said hollow stud (for a. purpose which will be hereinafter described), is held fast by a face-plate, 13, secured to said hollow stud,

as by screws 14, and by a clamping screw, 15, passing through said face-plate 13 and into the ring 10 in such a manner as to be capable of holding said ring 10 so as to prevent relative movement circumferentially between it and the hollow stud 9 and faceplate 13.

With said ring 10 set in any determined position the pivots 12 will be fixtures with respect to the frame of the cutter-bar and the levers or jaws 11 may be swung about said pivots by suitable operating means, preferably a device extending to a point outside the casing and near to the outer end of the cutter-bar. The device illustrated for this purpose is a cam-lever 16 mounted on the outer surface of the stud 9 so as to turn thereon. Said cam is here shown (see Fig. 19) as having three cam-slots, 17, in which pins, such as 18, at the power-points of the levers or jaws 11, are intended to work. By simply swinging said lever 16 in one direction or the other the multiple holding devices or jaws of the centering device are adapted in this case to be swung simultaneously equal distances toward or away from the axis of the pivot element 2, the cam slots 17 being all substantially alike. By means of this cam-lever a fine adjustment of the parts is obtained after the centering device has been positioned approximately as desired.

The principal holding elements vin this case are the flat faces, 19, of the studs, 20, projecting from said levers or jaws 11, that is, these are the principal faces for locating the cutter-bar with respect to the annular valve-ring and centering the cutter-bar so that the axis of its main pivot element 2 will be at the center of the annular valvering. For locating the cutter-bar and centering device in the direction of the axis of said valve-seat flat faces, 21, on the jaws serve, these flat faces being in contact with the flat face or valve-seat of the valve-ring.

The construction so far described is sufficient for effecting a fine adjustment of the centering device between two fixed limits affording a considerable range of adjustment of the tool so as to adapt it for use with valve-rings of various diameters. In order to increase the range of adjustment of said tool however and adapt it for use on a wider range of diameters it is necessary to provide additional means. This may be any suitable means for the purpose; but the specific means illustrated is a connection between the face-plate 13 and the ring 10 of the centering device which permits said ring to be set and held in a different rela tion circumferentially to said face-plate 13. While the principal element of this connection is the clamping screw 15, before described, said screw does not work in an ordinary threaded bore in the face-plate, but

instead passes through a comparatively lon slot, 22, therein and into the ring 10, of which it constitutes substantially a part and which it serves to shift to any position between the ends of the slot 22. When the screw 15 is at one end of said slot, as shown in Fig. 6, and is screwed home so as to hold the ring 10 from rotation relative to the face-plate 13, the arms 11 of the centering device have one range of adjustment between two limits. WVhen the screw 15 is at the other end of said slot, as shown in Fig. 8, and is screwed home, the ring 10 is set in a different position and the parts 11 have a different range of adjustment, by means of the cam-lever 16, between two limits one of which is different from one of the limits of the first setting. By simply changing the circumferential position of the ring 10 through the manipulation of the screw 15 and then fastening said ring in the desired position the range of use of the tool is very greatly increased as compared with a tool in which no such provision is made. In one case the parts are adjustable from the diameter shown in Fig. 8 down to the smallest diameter, represented by the projections 20 resting in the recesses 23, of the faceplate 13, while in the other case the parts 11 are adjustable in the same manner, by the camlever 16, from the limit illustrated in Fig. 6 to the maximum diameter shown in Figs. 17 and 18. The variation in the range of action results in this case from shifting the fulcra 12 of the holding levers or jaws 11, when the ring 10 is shifted, and the consequent swinging of said arms in different arcs in the new setting when the cam-lever 16 is swung to apply power to the power-points 18 of said levers 11 through the walls of the slots 17 In either setting of the parts provision should be made for holding the arms 11 in the positions to which they have been moved. Any suitable means may be employed for this purpose. Here a connecting link or rod is shown, at 2 1, as pivoted to the cam-lever 16 near the upper end thereof and as slidable through a bore in a post, 25, and adapted to be held at any point in its length by a clamping screw, such as 26. A stop-pin is illustrated, at 27, for engaging one of the lever arms 11 in the position of maximum expansion of the centering device.

As before stated, another important feature of the invention is the provision of means for adjusting the pivot element 2 crosswise of the cutter-bar from a point' outside the casing. In the construction shown this pivot element 2 is mounted in a sleeve, S, slidable crosswise of the cutterbar in the hollow stud 9 on the fixed frame of said bar. Here said sleeve has a comparatively large head, 28, preferably rectangular, and suitable means at its inner side is shown, at 29, for preventing turning of said sleeve on the cutter-bar. The rectangular projection 29 is intended, as shown in Fig. 9, to lie in the opening, 30, of the forked end of an actuating device for moving the sleeve crosswise of the cutterbar, the specific means illustrated for this purpose being a cam-slide, S, and the head 28 of the sleeve S, which has a double countersink, as shown in Fig. 11, for the purpose of receiving in this case a two-diameter adjusting nut, 31 (see Fig. 9) which may be adjusted to different positions lengthwise of the pivot element 2 for the purpose of increasing the length of said pivot element, substantially as in the third of our aforesaid applications. In order to prevent turning of the pivot element 2 in the sleeve S said pivot element is shown as having a way or groove, 32, with which a key, 33, in the sleeve (see Fig. 11) cooperates. Thus the crosswise adjustment of the pivot element 2 may be either that of the sleeve S alone or of said sleeve plus the desired extension of the element 2 as will be clear by referring to Fig. 9.

As before stated the specific means shown for shifting the sleeve S crosswise is a camslide S. At its lower end it is substantially wedge shaped in edge elevation, as shown, and the outer surface thereof lies between the under side of the head 28 and the cutter-bar frame proper, the under side of said head being preferably tapered in both directions from its center, as shown in Fig. i, in order to cooperate properly with the tapered face of the cam-slide. The adjacent face of the fixed frame of the cutter-bar is also shown as correspondingly tapered in order to improve the lines of the tool. For the purpose of operating said cam-slide any suitable means may also be employed. Said slide fills the space between the side-rails 6 of the fixed frame and at its upper end has a lug, 34:, projecting laterally therefrom and having a threaded bore for the reception of a short feed-screw, 35, with a knurled operating head, 36, at the extreme upper end of the tool. A portion of the shank of the feed screw is smooth so that said feed-screw may have a sliding move ment sufficient to obtain a rough adjustment of the position of the pivot element 2 with respect to the cooperating socket 3 of the cutter. To obtain a fine adjustment, however, as by means of a latch, 37, pivoted, at 38, on the crossbar 7 of the cutter-bar and adapted to work between the under side of said cross-bar and a stop, 39, on the feedscrew 35. By turning the knurled head 36 when the parts are in position the desired fine adjustment is obtained.

The sleeve S and the pivot element 2 proper mounted therein are both slidable freely relatively to each other, and also to the cutter-bar, in a direction crosswise thereof. For the purpose of keeping them in proper relation to the other parts when being adjusted crosswise of the cutter-bar and for maintaining any adjustment desired we have shown, at 10, a moderately strong spring fastened at one end to the cutter-bar frame and bent at its other end to engage both the head 28 of the sleeve and the nut 31 on the pivot element 2, for the purpose of exerting a strong pressure on both of them toward the outer face of the cutterbar, so that whether the cam-slide is moved down to shift the pivot element 2 crosswise toward the socket 3, or is moved up to permit the sleeve S on the pivot element 2 to withdraw from the socket 3, the pressure of the spring will always be in the proper direction for permitting and maintaining the desired crosswise adjustment of the pivot element 2.

We claim 1. A tool of the class described, comprising a cutter, an associated cutter-bar having near the cutter a plurality of parts relatively movable in a plane substantially parallel to that of the cutter bar for engaging the interior of a valve-casing and holding the cutter-bar to said casing, and means for effecting relative movement of said parts.

2. A tool of the class described, comprising a cutter, an associated cutter-bar having near the cutter a plurality of parts relatively movable in a plane substantially parallel to that of the cutter bar for engaging the interior of a valve-casing and holding the cutter-bar to said casing, and means for effecting relative movement of said parts and for maintaining the adjustment so obtained.

3. A tool of the class described, comprising a cutter, an associated cutter-bar having near the cutter a plurality of parts relatively movable in a plane substantially parallel to that of the cutter bar for engaging the interior of a valve-casing and holding the cutter-bar to said casing, and means carried by the cutter-bar and operable from a point outside the valve-casing for effecting relative movement of said parts.

4. A tool of the class described, comprising two main members one of which is a cutter and the other an associated cutterbar, means for wedging said tool in place between a pair of separated surfaces of a valve-casing, and adjustable means near the cutter for holding said cutter-bar to the interior of said valve-casing against movement in another direction.

5. A tool of the class described, comprising two main members one of which is a cutter and the other an associated cutterbar, means for wedging said tool in place between a pair of separated surfaces of a valve-casing, and adjustable means near the cutter for wedging said cutter-bar in place in the interior of said valve-casing against movement in another direction.

6. In a tool of the class described, a cutterbar having at different points a plurality of parts relatively movable in a plane substantially parallel to that of the cutter bar for engaging the interior of a valve-casing and holding the cutter-bar to said casing, means for effecting relative movement of said parts and a cutter associated with the cutter bar.

7. In a tool of the class described, the combination with a cutter-bar having near the working end thereof a plurality of parts movable in a plane substantially parallel to that of the cutter bar for engaging a valve-casing and holding the cutter-bar to said casing, of means for effecting relative radial movement of said parts with respect to a common center and a cutter associated with the cutter bar.

8. In a tool of the class described, the combination with a cutter-bar having near the working end thereof a plurality of parts relatively movable in a plane substantially parallel to that of the cutter bar for engaging a valve-casing and holding the cutterbar to said casing, of means for shifting said parts relatively to a common center and for holding them in such shifted posi- 1toion and a cutter associated with the cutter 9. In a tool of the class described, the combination with a cutter-bar havin near the working end thereof a plurality 0' parts relatively movable in a plane substantially parallel to that of the cutter bar for engaging a valve-casing and holding the cutterbar to said casing, of means for shifting said parts equal distances radially relatively to a common center and for holding them in such shifted positions and a cutter associated with the cutter bar.

10. In a tool of the class described, the combination with a cutter-bar having near the working end thereof a plurality of pivoted levers movable relatively to a common center in a plane substantially parallel to that of the cutter bar and each carrying a holding device for engaging a valve-casing and holding the cutter-bar to said casing, of means for swinging said levers toward or from said common center and a cutter associated with the cutter bar.

11. In a tool of the class described, the combination with a cutter-bar having near the working end thereof a plurality of pivoted levers movable relatively to a common center in a plane substantially parallel to that of the cutter bar and each carrying a holding device for engaging a valve-casing and holding the cutter-bar to said casing, of means for swinging said levers toward or from said common center said means including an operating cam-lever and a cutter associated with the cutter bar.

12. In a tool of the class described, the combination with a cutter-bar having near the working end thereof a plurality of piv oted levers movable relatively to a common center in a plane substantially parallel to that of the cutter bar and each carrying a holding device for engaging a valve-casing and holding the cutter-bar to said casing, of means for swinging said levers toward or from said common center and holding them in such shifted positions said means including an operating cam-lever and means for securing said cam-lever in any adjusted position and a cutter associated with the cutter bar.

13. In a tool of the class described, the combination with a cutter-bar having near the working end thereof a pivot element and also having an adjustable centering device arranged on one side of the cutter bar and concentric with the pivot element for engaging a valve-casing and holding the cutter-bar to said casing, of means for varying the adjustment of said centering device and a cutter associated with the cutter bar.

14. In a tool of the class described, the combination with a cutter-bar, of a pivot element and an adjustable centering device mounted on a common support on one side of said cutterbar, and means for varying the adjustment of said centering device and a cutter associated with the cutter bar.

15. In a tool of the class described, the combination with a cutter-bar, of a pivot element and an adjustable centering device mounted 011 a common support on one side of said cuttenbar, and means for varying the adjustment of said centering device with respect to said center and a cutter associated with the cutter bar.

16. In a tool of the class described, the combination with a eutterbar, of a pivot element and a multi-element adjustable centering device mounted 011 a common support on one side of said cutter-bar, and means for shifting the elements of said centering device equal distances radially with respect to said center to vary the adjustment of said centering device and a cutter associated with the cutter bar.

17. In a tool of the class described, the combination with a cutter-bar, of a pivot element and an adjustable centering device mounted on a common support on one side of said cutter-bar near one end thereof, op erating means extending lengthwise of said cutter-bar to a point near the other end thereof for varying the adjustment of said centering device and a tool element associated with the cutter bar.

18. In a tool of the class described, the combination with a cutter-bar, of a pivot element and an adjustable centering device mounted on a common support on one side of said cutter-bar near one end thereof, operating means including a cam-lever extending lengthwise of said cutter-bar to a point near the other end thereof for varying the adjustment of said centering device and a tool element associated with the cutter bar.

19. A tool of the class described, comprising a cutter and a. cutter-bar having a pivotal connection, and means on the cutterbar for imparting to the element of the pivotal connection carried thereby a movement transverse to the cutter-bar and from a point distant from said pivotal connection.

20. A tool of the class described, compris ing a cutter and a cutter-bar having a pivotal connection, and means on the cutterbar and including an operating rod extending to a point distant from said connection for imparting to the element of said pivotal connection carried by the cutter-bar a movement transverse thereto.

9.1. In a tool of the class described, the combination with a cutter-bar having near the working end thereof a pivot element and also having an adjustable centering device for engaging a valve-casing and holding the cutter-bar to said casing, of two separate means each extending to a point near the other end of the cutter-bar one for shifting said pivot element crosswise of said cutterbar and the other for adjusting said centering device.

22. In a tool of the class described, the combination with a cutter bar having near the working end thereof a pivot element and also having an adjustable centering device for engaging a valve-casing and holding the cutter-bar to said casing, of means for shifting said pivot element crosswise of the cutter-bar, and means for adjusting said centering device.

23. In a tool of the class described, the cmn'bination with a cutter-bar, of a pivot element and, an adjustable centering device mounted on a common support on said cut: ter-bar, means for shifting said pivot element crosswise of said common support, and means for adjusting said. centering device.

24. In a tool of the class described, the combination with a cutter-bar having near the working end thereof a pivot element, of means including a cam-slide for shifting said pivot element crosswise of said cutterbar.

25. In a tool of the class described, the combination with a cutter-bar, of a pivot element and an adjustable centering device mounted on a common support on said outter-bar, means including a cam-slide for shifting said pivot element crosswise of said common support, and means for adjusting said centering device.

26. In a tool of the class described, the

combination with a cutter-bar, of a pivot element disposed transversely thereof, and means for affording alternatively both a free movement of said pivot element crosswise of the cutter-bar and a gradual adjustment of the same in said direction.

27. In a tool of the class described, the combination with a cutter-bar having a pivot element, of a centering device cooperative therewith and having means for adjusting it to various positions corresponding to seats of different sizes and a tool element associated with the cutter bar.

28. In a tool of the class described, the combination with a cutter-bar having a pivot element, of a centering device having valve seat engaging portions movable into circles having centers common with said pivot and having means for adjusting it radially to various positions corresponding to seats of different sizes and a tool element associated with the cutter bar.

29. In a tool of the class described, the combination with a cutter-bar having a pivot element, of a centering device cooperative therewith and having means for setting it for large and small seats and a tool element associated with the cutter bar.

30. In a tool of the class described, the combination with a cutter-bar having a pivot element, of a centering device having valve seat engaging elements movable into circles having centers common with said pivot element and having means for setting it for large and small seats and a tool element associated with the cutter bar.

81. In a tool of the class described, the combination with a cutter-bar having a pivot element, of a centering device cooperative therewith and having a circuit of pivoted holding levers the fulcrum of each of which is shiftable to two different positions corre sponding to large and small seats and a tool element associated with the cutter bar.

32. In a tool of the class described, the combination with a cutter-bar having a pivot element, of a centering device cooperative therewith and having means for setting said device for large and small seats and also having means for obtaining a considerable range of adjustment in each of said settings.

33. In a tool of the class described, the combination with a cuttenbar having a pivot element, of an extensible multi-element centering device cooperative therewith and hav ing means for setting said device for large and small seats and a tool element associated with the cutter bar.

3%. In a tool of the class described, the combination with a cutter-bar having a pivot element, of a centering device having valve seat engaging elements movable into circles having centers common with said pivot element and having means for setting said device for large and small seats and a tool element associated with the cutter bar.

35. In a tool of the class described, the combination with a cutter-bar having a pivot element, of a centering device having valve seat engaging elements movable into circles having centers common with said pivot element and having a circuit of pivoted holding levers the fulcrum of each of which is shiftable to two difierent positions corresponding to large and small seats, said centering device also having means for 0btaining a considerable range of adjustment in each of said settings.

36. In a tool of the class described, a cutter bar having means constructed and arranged to engage within the circle of a valve seat to alone hold the same in position, and a facing cutter mounted on the cutter bar.

Signed by the said F RANK L. SMITH at Chicago, in the county of Cook and State of Illinois, this 4th day of February A. D. 1916.

FRANK L. SMITH.

Signed by thesaid THoMAsB. WILLIAMS at Orange, in the county of Franklin and State of Massachusetts, this 26th day of January A. D. 1916.

THOMAS B. l/VILLIAMS.

Witness:

FRED A. DEXTER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C.

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