US2318854A - Portable valve seat grinding means - Google Patents

Description

Mdy 11, 1943.

i E. A. HALL PORTABLE VALVE SEAT GRINDING MEANS 3 Sheets-Sheet 1 Filed NOV. 10, 1941 IE-lgww fmrEsTAfiqLL May 11, 1943. E. A. HALL PORTABLE VALVE SEAT GRINDING MEANS Filed Nov. 10, 1941 3 Sheets-Sheet 2 u wsig myw MW a May 11, 1943. E. A. HALL PORTABLE VALVE SEAT GRINDING MEANS Filed NOV. 10, 1941 3 Sheets-Sheet 3 EENEE TA- HALL Patented May 11, 1943 PORTABLE VALVE SEAT GRINDING MEANS Ernest A. Hall, Toledo, Ohio, assignor to The Hall Manufacturing Company, Toledo, Ohio, a corporation of Ohio Application November 10, 1941, Serial No. 418,432

5 Claim.

This invention relates primarily to the grinding of valve seats in "Globe and similar type valves used in high pressure fluid lines.

In such valves, it is necessary to have the seats perfectly ground to prevent leakage under high pressure, and in accomplishing such grinding it is necessary to remove the valve housing cap and with it the seating or plug member of the valve and its carrying stem to permit introduction of a portion of the grinding tool into the valve housing in position for the grinding member to have engagement with the valve seat. In many fluid pressure line installations, particularly in Navy vessels, the valves are welded into the line so that it is impossible to remove the valves for replacement or to transport to a convenient place for refacing the valve seats. In other cases, the valves can only be removed from the line at a considerable expense both in money and labor. It is, therefore, important to have a valve seat refacing tool which can be conveniently used at the point of installation of a valve Without disturbing the installation and which is capable of adaptation to valves of various sizes and designs and of having its grinding medium properly positioned relative to the valve seat to eilect the desired facing thereof.

An object of the invention is the provision of a novel, simple and eflicient valve seat grinding tool of the eccentric type adapted particularly for attaching to globe type valves or the like and grinding the seats thereof.

Another object of the invention is the provision of a tool suitable for refacing internal valve seats of globe type valves or the like, together with means for use in connection therewith for rigidly mounting the tool on a valve housing with its facing element projected therein in valve seat facing position and maintaining the tool, but not necessarily the facing element, in proper centered relation to the seat.

Another object of the invention is the provision in combination with an eccentric valve seat grinding tool, wherein the grinding wheel is driven at high speed about its shaft axis and the shaft axis itself is slowly revolved, of simple and novel means operable to disconnect the shaft from its revolving drive source without affecting the high speed driving of the shaft.

Another object of the invention is the proing adjustment, has moved into engagement with a valve seat and the frictional resistance to a free turning of the grinding wheel effected by such engagement, thus facilitating and simplifying the use of tools of this character particularly when operating on seats that cannot be seen during grinding, as in the case of globe type valves or the like.

The invention is fully described in the following specification, and two embodiments thereof illustrated in the accompanying drawings, in which- Figure 1 is a view of one form of grinding tool mounted in operative grinding relation to the valve seat of a globe" type of valve with the valve and a portion of the tool in central longitudinal section on the line ll in Fig. 2; Fig. 2 is a cross-section on the line 22 in Fig. 1, with parts in full; Figs. 3 and 4 are detail views of two of the gear members of the transmission shown in Fig. 2; Fig. 5 is a central longitudinal section of a different form of grinding tool with adapter attached and with parts in full; Fig. 6 is a section on the line 6-6 in Fig. 5; Fig, '7 is a reduced side elevation of the tool and adapter shown in Fig. 5, with a part broken away; Fig. 8 is a bottom end view thereof with a part broken away; Fig. 9 is a fragmentary cross-section on the line 99 in Fig. 7, with the motor partly broken away; Fig. 10 is a side elevation of the tool in operative attachment to a fluid line valve, with parts of the tool and valve broken away; Fig. 11 is a diagram of the wiring and ammeter used in connection with the tool motor, and Fig. 12 is a face view of a portion of an ammeter indicating a motor torque reading thereon.

Referring to the drawings, A designates a valve which may be of the globe type, disposed in a fluid pressure line B and having an internaltapered valve seat 5 and in one side of its housing an opening 2 through which the plug member of the valve is introduced and controlled, as well understood in the art. In Fig. 1 this valve is 01. angle type while in Fig. 10 it is of straight type. When the valve is in use, the opening 2 is closed by a gland plate f not shown) through which the valve stem projects and which is held to the housing flange by suitable screws or bolts. The flange 3 is of annular form and, in addition to forming the opening 2, is customarily recessed at its inner top edge to form a gasket seat 4. The openings 2 and flanges 3 for various valves are of different sizes and types, as well understood in the art.

A valve seat grinding tool C is intended to have its grinding wheel carrying end projected into a valve housing into valve seat grinding position through the housing opening 2 and is adjustably mounted on the housing in centered relation to its valve seat by an adapter D, which is seated on and rigidly secured to the flange 3.

The adapter D, in the embodiment shown in Fig. 1, comprises a collar 6 having an annular flange l for seating on and being secured to the valve housing flange 3 by screws ii. The collar 6 has at its inner end a part 9 for fitting into the opening of the housing flange 3 and for cooperating with the wall thereof to center the adapter relative to the valve seat, and also has a part H) for seating in the recess 4. The collar 6 has its internal surface, as well as the external surface of the part 9 and seating surface of the part l0, machined to fit the parts with which they coact.

A guide sleeve H is mounted in the collar 6 and preferably projected at its inner end beyond the part 9 to near the valve seat to be ground, while its outer end is flanged over and rigidly secured to the outer end of the collar 6 by screws l2, or in any other suitable manner. This guide sleeve is preferably machined inside and out to adapt it to closely fit the collar 6 and to provide a smooth bore which i perfectly centered relative to the housing opening 2 and form a guide in which the grinding tool C may be mounted for feeding movements axially of the valve seat during a seat grinding operation, as hereinafter described.

In the grinder shown in Figs. 1 to 4, l designates the gear case having the tubular extension I5 at one end for fitting into and having axial reciprocator movements in the guide sleeve II. A motor housing i1 is mounted on the opposite end of the gear case in offset relation to its center. In the present instance. the inner end portion of the motor housing forms a cover for the gear case and is removably mounted thereon in any suitable manner.

The tubular extension l6 opens at its inner end into the gear case, and its inner surface forms a bearing for a rotatable sleeve which extends at its upper end into the gear case l5 and at its lower end slightly below the extension l6. An annular flange 2| near the inner end of the sleeve has bearing engagement with the inner end of the extension IB, preferably through a gasket, and is engaged within the gear case in opposition to such bearing by a flanged collar or plurality of clips 22 secured within the case. A collar 23 is mounted on the outer end of the sleeve 2|) to coact with the extension Ill in opposition to the bearing flange 2| toprevent axial movements of the sleeve relative to the extension.

The sleeve 26 has an eccentric bore in which a grinding wheel carrying shaft 25 is mounted for relative rotary movements in suitable inner and outer bearings 26 provided therein. A grinding wheel 21 is carried by the outer end of the shaft 25 without the outer end of the eccentric sleeve 20 and is suitable for grinding a valve seat I into which it may be projected. The shaft 25 at its inner end is connected by a flexible shaft 28 to the hub or shaft of a gear 29 that is suitably mounted for free rotary movements in the inner gear case covering end of the motor housing H.

The drive motor armature shaft 80, that is mounted in the housing H, has its inner end projected through a bearing 3| in the inner end of the housing and into the gear case l5 where it carries a gear 32 in driving engagement with the gear 29. The motor shaft also carries a small worm gear 33 in driving engagement with a large worm wheel 34 (Fig. 2), which latter is on the hub or shaft of a worm 35 mounted crosswise ell within the gear case and in driving mesh with a worm wheel 36 on the inner end of the eccentric sleeve 20. The gear connections of the motor shaft with the grinding wheel shaft 25 and with the eccentric sleeve 20 are such that the grinding wheel is driven at high speed, preferably about 5,000 to 10,000 R. P. M., while the eccentric sleeve is driven at a slow speed of approximately 6 to 30 R. P. M., thus effecting a slow revoluble movement of the grinding wheel shaft axis while the grinding wheel itself is rotating at a high speed about such axis for the purpose well understood in connection with eccentric valve seat grinders of this character.

The feed means for the tool 0, by which it is advanced or retracted in the adapter D to efiect movement of the grinding wheel 21 toward or away from a valve seat, comprises, in the present instance, a screw 40 which projects down through a side opening in the gear case and is threaded into the flanged upper end of the adapter guide sleeve. The screw 40 is mounted in a manner to prevent axial movements thereof relative to the gear case, but is adapted to have rotary move ments therein. It is thus apparent that a turnmg of the screw 40 will ause lengthwise movement of the tool in one direction or the other in the guide sleeve I I. The screw 40 at its outer end is provided with a hand wheel ll to facilitate hand turning thereof.

In the use of tools of this character, it is important that the grinding wheel have only light engagement with the valve seat when the grinding operation is started and that the feed of the grinding wheel to the seat be very gradual as the grinding progresses, so as not to cause injury to the seat. In blind grinding operations such as illustrated, where the grinding wheel and valve seat being ground cannot be viewed during a setting or grinding operation, it is important to have some means other than the tool feeding means for determining when the grinding wheel is in engagement with the seat and, within limits, the pressure or force of such engagement, or the resistance offered by the engagement to a relative turning of the grinding wheel. Two means for determining this are preferably but not necessarily used together, one being manually operable and enabling th operator to determine by "feel, if the grinding wheel is in engagement with the valve seat and the approximate pressure of such engagement, and the other being automatic and of an electric nature to indicate, through torque or load on the motor, when the grinding wheel is in engagement with a valve seat and the force of such engagement.

For the purpose of manual control, the outer end of the motor shaft 30 is projected through the outer end of the motor housing I! and provided in exposed position with a small knob or wheel adapted to be grasped and turned by a hand of the operator. By turning or attempting to turn the knob 45 when the motor is at rest, the operator can determine if the grinding wheel is free from engagement with the valve seat and, if in engagement therewith, the approximate torque or load on the motor to effect a turning of the grinding wheel. It is apparent with this means that the motor shaft may be quite freely turned if the grinding wheel is free from engagement with the valve seat and that the resistance to such turning determines the approximate extent of engagement of th grinding wheel with the valve seat.

It is possible, during such a turning of the moand 2.

tor shaft, to disconnect the shaft from the eccentric sleeve so that the force required to turn the motor shaft will thereby be reduced, thus making the resistance to a turning of the motor shaft more sensitive to the feel of the operator than would otherwise be the case. It is also necessary to disconnect the eccentric sleeve 20 from the driving source during a diamond dressing of the grinding wheel so the axis of the wheel will be stationary during such action. To accomplish this, the motor is disconnected from the eccentric sleev 20 by the provision of a releasable clutch means between the gear wheel 34 and the hub portion of the worm 35 on which it is mounted, as shown in Fig. 2. In this connec tion, a clutch pin projects from within the hub portion of the worm 35 into a keyway 5| in the hub of the gear 34 and is shiftable in said keyway and in a slot in the worm hub into and out of register with an annular recess 52 in the wheel hub, so that when-the pin is in register with said recess the gear wheel may turn freely on the worm and when the pin is in the keyway 5| the wheel is in driving connection with the worm. The movement of the pin 50 is controlled by a rod 53 which projects axially through the worm and has one end at least exposed and provided with a hand grip or knob 54. This rod is yieldingly held in one position or the other of its movement by a spring pressed detent 55 in the worm engaging either one or the other of a pair of recesses 56 in the rod.

After a grinding tool and adapter have been mounted on a valve casing preparatory to grinding a valve seat, it is preferable in practice to first turn the feed adjustment to move the grinding wheel into engagement with a valve seat, which engagement can be determined by "feel" by a turning of the knob 45, and then to back the tool off slightly to release the grinding wheel from engagement with the valve seat, which condition can be determined by a free turning of the motor shaft. The operator. of course upon a feeding adjustment of the tool. can determine when the grinding wheel has moved into stop engagement with the valve seat by the resistance offered to a further turning of the feed screw. It is found, however, that this adjustment, due to the presence of the screw action, is so powerful in its nature that it is not sufficiently sensitive, by

"feel on the part of the operator, for him to determine, to any such degree of nicety as is necessary, the extent of pressure engagement of the grinding wheel with the valve seat. For this reason, it is highly desirable, particularly where fine work is required, to provide some means entirely independent of the feeding adjustment which is operable to indicate the pressure of the grinding wheel against the valve seat when the motor is at rest and also some means to indicate such pressur during a grinding operation.

The electrical indicating means employed, which is responsive to pressure of the wheel against the seat and is only active during a grinding operation, consists in interposing an ammeter in the circuit with the motor, so that any variation in the motor torque can be determined to a nicety by the ammeter reading. Such a circuit with ammeter and motor therein is diagrammatically shown in Fig. 11, and Fig. 12 illustrates the reading portion of an ammeter. When the motor is running free with the grinding wheel out of engagement with the valve seat, the ammeter reading, for instance, will be between "1" When the grinding wheel is brought into engagement with the valve seat, the reading will be increased according to the extent of frictional engagement of the wheel with the seat.

"This means is found very effective in determining when the wheel is in engagement with a valve seat and the extent of such engagement, and will also visually indicate to the operator when a seat has been ground sufficiently to remove all irregularities or high spots therein and to make it perfectly round for efficient valve seating purposes.

In the form of the invention illustrated in Figs. 5 to 10, the motor is mounted at a side of the tool instead of at an end, and its shaft is transverse to the grinding wheel shaft instead of parallel thereto as in the form previously described. In this form of the invention, the adapter and its manner of feeding connection with the tool are also shown as changed over the form of adapter and feeding connection shown in the previous figures.

In Figs. 5 to 10, the fluid line valve is designated A the same as before, the grinding tool is designated C and the adapter is designated D'.

The adapter D comprises a guide sleeve 60 having a cylindrical bore therein for receiving and guiding the feeding movements of the shank portion of the tool housing and has its outer end formed with a flange Bl for seating over the flange of the valve casing which forms the opening through which access to the valve seat may be had and which is adapted to be secured to such casing by screws 62 (Fig. 10). The outer end of the guide sleeve 60 is also provided with an annular projection 63 for fitting into the depression 4 of the valve casing to center the sleeve relative to the valve seat.

The housing of the tool C forms a gear case 65 which is closed at its outer end by a cap member 66 and is provided at its inner end with a cylindrical extension 61 forming the shank portion of the tool which is fitted in and guided by the adapter sleeve 65. A shaft 10 carries the grinding wheel H and projects through and is suitably mounted for free rotary movements in the eccentric bore of a sleeve I2, which in turn is mounted for rotary movements in the cylindrical extension 51. The eccentric sleeve 12 is held against axial movements in the extension 61 by a projection 13 on the inner side of the gear case cover 66 projecting inwardly through the gear case and engaging an annular flange II on the inner end portion of the sleeve. A shaft section 15 is mounted in the cover 56 through a cylindrical outward extension 16 thereon with its axis parallel to that of the shaft I0 and centered with that of the eccentric sleeve 12. The shaft 15 projects at its inner end into the gear case and is connected to the inner end of the shaft 16 by a flexible shaft section 'll extending through the gear case.

The motor has its housing mounted on a side of the gear case with it armature shaft 8| projected into the gear case and in driving connection with the inner end of the shaft 15 through a pair of bevel gears 82, thus providing a drive for the grinding wheel shaft from the motor. The motor shaft Bl also carries a frame gear'fl3 in mesh with a worm 84 mounted crosswise in the gear case 85 at a side of the inner end of the eccentric sleeve 12 and in mesh with a gear 85 on said sleeve, as shown in Figs. 5, 6 and 9. It is thus apparent that the grinding wheel shaft is driven at high speed and the eccentric sleeve is driven at a very much slower speed.

The feed adjusting means for the tool C includes a yoke 90 having at its inner end a collar ll which receives the inner end of the adapter sleeve 60 and i attached thereto by screws 92. These screws are threaded in the collar and preferably engage at their inner ends in an annular recess inthe sleeve 60 to permit the tool to be turned relative to the adapter to a position which is most suitable for the particular application, and to allow for interchangeability of various other size adapters. Arms 93 project in parallel relation outwardly from the collar 9| at opposite sides of the gear housing 6| of the tool and are attached at their outer ends to a collar 94, which is rotatably engaged with the inner end of a nut which is threaded on the outward extension 16 of the gear case cover 66 for lengthwise adjustment thereon. The collar 94 is rotatably held in engagement with the sleeve 95 by a ring 96, that is threaded on the outer end of the nut 95 and held in proper adjusted relation thereto by a set screw 91 (Fig. 5). The ring 96 forms a hand grip which facilitates turning of the nut 95 on the extension 16 to cause axial adjustment of the tool in one direction or the other relative to the adapter D and the attached feed yoke 90.

In this form of tool, the outer end of the shaft section of the grinding wheel shaft is projected beyond the outer end of the housing extension Hi, and is provided at such end in ex posed position with a knob or small hand Wheel I00 which may be grasped by a hand of the operator and turned to efiect a turning of the grinding wheel, so as to determine by feel the relation of the grinding wheel to the seat to be ground, or the extent to which the grinding wheel is engaged with the valve seat.

For the purpose of disconnecting the eccentric sleeve 12 from the motor drive to facilitate hand turning of the grinding wheel shaft, the worm 84 has a loose eccentric mounting on its shaft I05, as shown in Fig. 6, so that the gear, by a turning of the shaft, may be thrown into or out of mesh either with the drive gear 83 or the driven gear 05. The shaft I05 has one end projecting without the gear case 65 and provided with a control lever I06 which, when moved to the right in the direction of the arrow in Fig. 10, effects a release of the worm 84 from the gear 85. It is also necessary to disconnect the eccentric drive means from the motor during a dressing operation on the grinding wheel.

In the use of either tool embodying the invention, the particular adapter D or D' is rigidly attached to the valve casing, and thereby placed in centered relation to the valve seat to be ground. The valve grinding tool, if not already in the adapter, is mounted therein by placing its cylindrical shank portion within the guide sleeve of the adapter end in one case connecting the adjusting screw 40 to the adapter and in the other case attaching the feed adjusting yoke 90 to the inner end of the adapter sleeve. The feed means is then adjusted in one case by turning the screw 40 and in the other case by turning the adjusting nut 95, so as to feed the grinding wheel toward and into stop engagement with the valve seat. The operator then, before starting the grinding operation, turns the feed back slightly to relieve the pressure of the grinding wheel against the seat a desired extent, which is determined by the resistance encountered upon a turning of the grinding wheel through hand engagement of the turning knob in one case and I00 in the other. In this manner, the operator may determine if the grinding wheel is entirely released from engagement with the seat, which is usually desirable before starting a grinding operation. or to what extent, as to pressure, it is engaged therewith. The grinding wheel having been placed in proper initial adjustment to the valve seat, the motor is started and the feed means operated to slowly feed the grinding wheel into engagement with the work and to intermittently continue such feeding operation as the grinding progresses and until completed. The operator can determine by the ammeter reading if the grinding wheel is in engagement with the seat face and also the pressure of such engagement. If the grinding wheel, upon starting the motor, is free from engagement with the valve seat, the ammeter will indicate a reading, for instance, between 1" and 2, and this reading is increased as the grinding wheel is fed into engagement with the valve seat and in accordance with the extent or pressure of such engagement. During grinding the ammeter will fluctuate several points, and upon completion of the grinding operation the reading will return to approximately the free running indication and will hold steady, showing that the valve seat has been ground to perfect circular form. A skilled operator can always determine the condition of the valve seat during a grinding operation by merely watching the ammeter, thus obviating the time consuming operation of removing the grinding means at intervals from the article being ground so as to enable the condition of the valve seat to be determined by a separate testing operation.

I Wish it understood that my invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of numerous modifications and changes without departing from the spirit of the claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent, is:

1. In a portable valve seat grinding machine, a grinding wheel carrying shaft, means without said shaft and forming a rotatable eccentric mount therefor, said means and shaft being relatively rotatable about axes parallel to each other, a power source, separate driving connections between said source and each of said shaft and means, the connection with said means including a train of gears, and means manually operable to connect or disconnect the driving connection between certain of the gears in the train and including a worm and a worm wheel together wit an eccentric mount for the worm which is revoluble to throw the worm into or out of engagement with its companion.

2. In a portable valve seat grinding tool, a housing having a tubular guide extension, a grinding wheel carrying shaft projected from the housing through said extension, mean mounting said shaft for independent rotatable and revoluble movements in said extension, an adapter for rigid attachment to a valve casing in concentric relation to its valve seat to be ground and having a means for receiving and guiding said extension for feeding movements of the tool relative to the adapter and axially of the shaft, and means connecting said adapter and housing and operable to effect feeding movements of one relative to the other.

3. Ina portable valve seat grinding tool, a housing having a tubular guide extension, a grinding wheel carrying shaft projected from the housing through said extension, means mounting said shaft for independent rotatable and revoluble movements in said extension, an adapter for rigid attachment to a valve casing in concentric relation to its valve seat to be ground and forming a means for receiving and guiding said extension for feeding movements of the tool relative to the adapter and axially of the shaft, said adapter including a collar for attaching to the work and a removable bearing sleeve mounted in and projected through said collar and held thereby in concentric relation to the valve seat to be ground and forming the guide bearing for the tool extension, and means connecting said adapter and housing and operable to effect feeding movements of one relative to the other.

4. In a portable valve seat grinding tool, a housing having a tubular guide extension, a grinding wheel carrying shaft projected from the housing through said extension, means mounting said shaft for independent rotatable and revoluble movements in said extension, an adapter for rigid attachment to a valve casing in concentric relation to its valve seat to be ground and forming a means for receiving and guiding said extension for feeding movements of the tool relative to the adapter and axially of the shaft, said adapter including a guide sleeve for attaching to the valve casing and an element rotatably carried thereby and embracing a part of the tool housing in axially spaced relation to said extension, and screw means connecting said housing and said adapter element and operable in conjunction with the latter to eiTect feeding movements of the housing relative to the adapter.

5. In a portable valve seat grinding tool, the combination with a housing having a cylindrical guide extension, a bearing sleeve mounted for concentric rotation in said extension, a grinding wheel carrying shaft projecting through and mounted for rotation in said sleeve eccentric to the axis of rotation of the sleeve, and means for rotating said sleeve and shaft at difierent speeds, of an adapter for rigid attachment to the work in concentric relation to its valve seat t be ground and forming sleeve means for receiving and guiding said extension for feeding movements of the tool relative to the adapter and axially of said shaft, and means connecting the tool housing and adapter and operable to eiTect feeding movements of one relative to the other.

ERNEST A. HALL.

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