US2248262A - Grinding valve stems and tappets - Google Patents

Description

July 8, 1941 G. c. wlLHlDE GRINDING VALVE STEMS AND TAPPETS ul n |l f i n |r l- L t., f

.Filed Aug. 9, 1938 Patented July 8, 1941 GRINDING VALVE STEMS AND TAPPE'IS Glenn C. Wilhi'de, Towson, Md., assigner to The Black & Decker Manufacturing Company, a corporation of Maryland Application August 9, 1938, Serial No. 223,845

-3 Claims.

In the surfacing or resurfacing of internal combustion motor valves and seats, the effective length of the valve stern isvincreased, and it thus becomes necessary, particularly in the kind of motor having nonadj-ustable tappets, to shorten` the stem by grinding its `lower end, i. e. the end which contacts the tappet. It is also found that the upper surfaces of the tappets, and the lower or tappet ends of the valves become defaced and must be attened and trued to give satisfactory operationV of the reconditioned motor,

The present invention relatesV to valve stern grindingv apparatus of the general class of that shown in Patent` 2,151,528-, filed February 14, 1936, granted March 21, 1939, and assigned to the assignee of the presen-t application.

The object of the invention is to provide an improved apparatus for trueing the ends of internal combustion motor valve. stems, and valve tappets, and for reducing the valve stems to the proper length after surfacing or resurfacing the valve and/or seat and for vtrueing and grinding the ends of studs, buttons, and the like which are suited tov similar treatment.

It is also of interest that the present apparatus is adapted without kchange to use in connection withvalves of different sizes, and particularly to the grinding of the valve stems'and tappets of a well known type of motor in the low priced class and of the V- arrangement which is equipped with tappet end valves and nonadjustable tappets,v and other valves and tappets.

An important feature of the apparatus is. the valve stop, or abutment which eliminates any possibility of the valve or gauge swinging to the side, oryielding upwardly in operation so thatr the surface produced at the end of the stem might be out of line, i. e. not at right angles to the valve axis. v

The defect thus avoided would result in limproper adjustment ofl the valve, and tend to give a variation of the 'valve opening as the valve rotates, and rotation is generally considered desirable, if not essential to the operation of the poppet type of internal combustion motor valva The invention also includes an improvement.

in the grinding wheel which avoids heatingV in the grinding or trueingrof the end surfaces of valve stems and tappets, and thus avoids burning of the metal.

In the accompanying drawings, I have illustrated avalve stem and tappet grinding attachment embodying the features oi the invention in the preferred form.

In the drawings: f Y

Figure 1 is a front elevation of a refacer head and wheel, and the attachment of the invention., showing a valve in the position for grinding or trueing the end surface of its stem'.` v

FigureZ is a top plan view of the valve, and/ or gauge stop, or abutment, for determining the positionv of the valve relatively to the wheel, and. hence the length ofthe stem. Y

Figure 3 isan elevation similar to Figure l, but broken away, showing the gauge in position. for determining the setting of the abutment.

Figure 4 is a view taken from the. same direction, of a fragmentary nature showing the position of the parts in the grinding of a valve tappet.

Figure 5 is an elevation taken from the right. in Figures 1 and 3 showing a valve stem in grinding.;l position in the carriage. y

Referring to the drawings. by numerals, the i1- lustration includes a valve refacer .head Iy onl which is mounted a valve refacer wheel 2 driven by a belt 3 from any suitable source not illustrated.

The present machine includes the shaft- 4 which is clamped in a hole 5, bored in the head I in exact parallelism with the axis of the grinding wheel v2, andA is positioned by the collar 6. The surface 4. of the shaft 4 is iinished' with accuracy about itsr axis, and the hub 'I of the grinder carriage is. also finished internally and is mounted to slide along shaft 4, and to swing about its axis. The hub.y I of the carriage or bracket 8, to be further described, has imparted toit a tendency to the right due to the spring 9. coiled about the shaft 4 between the hub 'I- and. the-collar 6, and the carriage Il is adjusted with accuracy alongv the shaft by the thumb nut I0.

which is provided with a Vernier I0', all in substantial accordance with the previous application above cited, the Vernier and thread being to determine valve clearance, etc. The carriagev a further comprisesr a plurality of seats lll and `I2 which are shown in end view in Figure 5, and in dotted lines in Figures 1 and 3. These. seats are of downwardly tapering cross-section as seen in Figure 5, and as seen in Figures 1 and 3, are elongated in the direction of the axis of the wheel, and in exact parallelism thereto, the seat l2 being the shorter of the two.

Cooperating with these seats, is a clamp bar I4 which is secured in overlying clamping relation to the seats. II and I2 as shown in Figures 1 and 5, by means of a bolt I5 which is seated in theswinging head I5 of the carriage 8, and extends through a suitable opening shown in the form of a vertical notch or groove in clamping bar I4. The same being indicated by reference character I4', the wing nut I1 forces the clamping bar I4 down against the work.

It is of advantage that the clamping bar I4 as shown in Figure 5, has arcuate seats or notches I8 and I9 shown as of different radii, in its top and lower surfaces on one side of the screw I5, and feet I8' and I9 at the end edges side of said notches. On the other side of the screw I it has a clamping surface 25 and a short foot 28', and opposite the surface 20 it has a flat surface 2I, and a foot 2l. The bar can be turned end for end, or it can be turned upside down to bring the notches of different sizes or the presser feet 20 and 2I into cooperation with the seats II and I2 to clamp work of different diameters to the carriage to be presented in proper grinding relation to the stone.

An important feature of the invention resides in thevalve and gauge stop or abutment 22 shown in plan in Figure 2 and side elevation in Figure 3. This abutment or stop consists of an elongated shank 24 slotted at 25 to be engaged by Va screw 2x5-shown extending downwardly from thelbottom of the head I6 of the carriage 8 in Figure 3. The shank 24 slides in the guiding seat 2 1 shown in end elevation in Figure 5.

This abutment or stop 22, as seen in plan View Figure 2, is in the form of a Y, having two convergingarms 28 and 29 at its end at the right in Figure 2, which is in the operative position, remote from the grinding wheel 2. The Y arms 28 and 29, as shown in elevation in Figures 1 and 3, ,are of considerable extent in a direction at right anglesto the diameter of the valve or gauge which diameter connects the tangent points 28" and 29", i. e. they extend upwardly to and beyondthe horizontal plane of the center of the valve, or axis of the Valve 3l), as seen in Figure 1, said Valve being clamped in the seat I I for grinding, and likewise above the horizontal plane of the axis of the gauge 3i when similarly clamped. It is also of importance that the inner surfaces 28' and 29 of the Y- arms 28 and 29, are related to each other,` and to the axis ofthe valve in accordance with the angle of the seating surface 32 of the valve to be treated. It is, of course, important that the seat or guide 21 is parallel to the axis of the wheel, as is likewise the stem 33' of valve 30 and the stem 33 of gauge 3| when clamped in grinding and gauging position respectively asshown in Figures 1 and 3, and it is of importance that the abutment, or stop 22 when adjusted toward and from the wheel 2 maintains its gauge or positioning surfaces 28', 29', in the exact angular relation to the wheel axis, and valve and gauge axis described for any and all adjustments. The abutment 22 has the advantage that it engages the valve at opposite tangent points or elements so that there is no tendency to irlateral or upward deflection, and being limited to engagement at two opposite tangent points, there is little chance for inaccuracy due to grit and dirt particles. Further, the gauge is suited to any size of Valve of substantially the same angle as the abutment on account of its lateral extent, and the vertical extent of the flat surfaces adapts the gauge to treatment of valves having stems of a Variety of diameters. The valve stem grinding operation is a process requiring extreme accuracy and it is the purpose of this apparatus to 'meet this requirement to better advantage than any apparatus hitherto before provided. To

this end the abutment 22 hasits shank 24 integral with the upright members 28-a and 29--a on which the valve contacting surfaces 28 and 29 are formed and this shank, while it is adjustable in the direction of the wheel axis, is rigidly related to the seat II, II, which seat is an integral part of the carriage. To provide for the adjustment, the abutment shank 24 is elongated in the direction of the grinding wheel aXis and this shank fits closely in the guiding seai-l or Way 21.

The gauge 3I is of interest in that it is adapted by merely reversing it end for end to use in the treatment of valves of two diierent sizes. The gauge 3| includes a rod 33 of approximately twice the overall length of the valve to be treated, being permissibly of more than twice this length. This rod which is to advantage substantially the diameter of the stem of the valve to be treated carries slidably mounted thereon a valve head member 35 which is secured in adjusted position on the stem by means of a thumb screw 36, or in any suitable manner. This .valve head member 35 is provided with two oppositely disposed Valve head shapes or dummies 38 and 39, provided with oppositely disposed tapered surfaces 38' and 39' of the angle of the valves to be treated. The gauge 3I is also shown as provided with different size collars 40, 4I, and 42, to suit the different size holes for the valve guides in the engine block. The Valve shapes 38 and 39, as shown in Figure 3, are adapted to lit in the seats of the 60' and 85 horsepower motor of the V type suggested. Valve shape 39 also fits the valve seat of a four cylinder motor of the same make and the bow or elbow 4I fits in the valve guide hole of this motor. The purpose of the collars is to hold the gauge in upright position .in place of the valve so that it will give the exact measurement between the seat surface and the operative surface of the Valve tappet, i. e. the upper surface ofthe valve tappet, in its lower position, i. e. the seated position of the valve. Figure 3 shows the gauge in final adjustment to the gauging position for a valve of the 60 horsepower V-type motor for grinding the end of the valve stem, the abutment 22 being clamped. The carriage is then swung out of line with the stem and thel valve is placed in seat II in place of the gauge.

Figure 1 shows the tappet end valve 38 in grinding position, and Figure 4'shows a valve tappet clamped in grinding position in the seat I2, the valve 30 described being in the seat II, see Figure 5. Figures 1 and 3 show a notch 44 in the head I6 of the grinder carriage 8 to accommodate the collars ISU- 42, the collar 4I being shown as integral with the valve shaped gauge member 35.

In the operation of the gauge 3I the valve and spring, and valve guide being removed from the engine casting, the gauge is inserted in place of the valve, and the proper collar 49-42 in place of the valve guide. 'I'he valve member 35 is then moved down until the surface 38 or 39', whichever is being used, depending upon the size of the valve being treated, engages the valve seat. The screw 36 vis then tightened, clamping the Valve member 35 in position, whereby the gauge is seated in place vof the Valve. The gauge 3I is then removed from the valve seat, and placed in the seatV I I in the carriage 8, and being slid along the same until its end 45, corresponding to the tappet end of the valve, is in contact' with the wheel 2. It is then clamped in position and the abutment 22 is set with its abutment surfaces 28 and 29 -in Contact with the seating surface 38' of the gauge. The gauge 3i is then unclarnped by releasing the thumb nut Il which has been tightened in the first instance to clamp it, and a valve 3i) is clamped in its place, the carriage having been swung out of alignment with the wheel so that the end of the valve stem St' does not contact the wheel. It is of importance that the seating surface 32 of the valve bein close contact with the abutment surfaces 28 and 25', of the stop or abutment 22 before clamping. When the valve has been clamped by means of the block lli the screw il being tightened for this purpose, the nut It is turned sufficiently to provide the desired clearance, and the carriage is swung to move the 'tappet end 2t of the valve across the surface d8 of the stone 2.

In clamping the valve stem in seat l l, l i', the latter being to the right of notch d., the presser foot 2! of the clamping bar lli bears on the valve stem holding it in the groove or seat il, il. It is of interest that the valves for the different sizes of motors have stems of different diameters which are clamped in this Way. This does not, however, interfere with the accuracy of adjustment, and/or grinding because of the arrangement of abutment surfaces 28 and 29whereby they intersect on a line parallel to the grinding plane lil and in the center upright plane of seat il. This is the plane in which the-axis of the valve stem moves up and down, as its diameter changes, i. e. as valve stems of different diameters are clamped in the seat.

Other valve parts, and pins, studs, etc., requiring trueing and attening of their ends may be ground in this way. The machine shown is also equipped for the trueing or grinding of valve tappets 53 by using seat l2 as shown in Figure 4, and these tappets are of different diameters to which the radii of arcuate notches i8 and I9 in clamping bar I4 may correspond.

Another feature of novelty is that the stone 2 in the improved form has a narrow circular grinding surface 48, preferably of flat radial contour, as seen in Figures 1 and 5 which gives a relatively limited contact with the valve stem, and prevents heating, and consequent burning and deterioration of the metal surfaces being treated. Inside ther peripheral area i8 the axial end 49 of the wheel is dished or concave to a greater or less degree as shown at 5S.

The edge portion or grinding surface of the stone, as illustrated in the drawings is approximately the average width or diameter of a valve stem and provides not only for satisfactory grinding but for cooling of the stone and the valve stem by the currents of air carried by the frictional action of the inner and outer substantially cylindrical surfaces of the wheel or stone.

This arrangement is particularly desirable in the grinding and trueing of valve stems and tappets and the like where a at grinding plane is essential and the expedient of grinding on the flat end surface of the wheel must almost necessarily be adopted. Also the fact that the ,valve stem is stationary in grinding, is a contributing element to the objectionable heating which takes place with the old type of wheel, and is avoided by the improved construction.

I have thus described a grinder construction and a grinding operation in accordance with my invention, and, as examples of the same, the description. being specific and in detail in order that the manner of construction applying, operating, and using the invention may be fully understood; however, the specie terms herein are used in a description rather than in a limiting sense, the scope of the invention being defined in the claims.

What I claim as new, and desire to secure by Letters Patent is:

1. The combination with a grinder having a wheel with a substantially flat grinding plane, and a carriage mounted to move on a path parallel to said plane and having a valve stem seat extending in a direction normal to said plane and adapted to hold a valve stem disposed normally to said plane the said carriage having a second seat parallel to said rst seat and of greater diameter and adapted to receive a valve tappet in grinding position as to said wheel and a transverse clamping bar extending across both seats intermediately of their lengths and a clamp.. ing screw for said loar between said seats.

2. A valve stem grinder having a grinding wheel with a substantially fiat grinding plane and a carriage movable in a direction parallel with said plane, said carriage having an integral elongated valve stem seat with downwardly converging valve stem supporting surfaces said seat extending at right angles to said plane, ,and arvalve abutment comprising an elongated shank, the carriage having an integral guideway therefor, said shank being adjustably mounted in said guideway and clamping means therefor, the shank and the adjustment thereof being parallel to said seat, said abutment having upright portions integral with said shank and at the end thereof remote from the Wheel with fiat upright abutment surfaces formed thereon and converging at an angle equal to the angle of the seating surfaces of the valves to be treated, the planes of said converging surfaces intersecting on a line which is parallel to the grinding plane and extends vertically through the center line of said seat, said surfaces being of extended vertical and horizontal length, providing for the grinding of the stems of valves with heads and stems of a wide variation as to their diameter.

3. In a 'valve seat grinding apparatus a valve abutment which as seen in top plan is of Y shaped form and is in a single integral piece, said valve abutment having an elongated at sided finished shank, adapted to fit closely and to slide in a flat sided guideway and having at its bifurcated end two rigid integral uprightl converging members extending up from the respective bifurcations of the Y, said members having two opposed, plain, flat abutment surfaces elongated vertically and horizontally and converging at an. angle equal to the angle of the seating surface of the valve to be treated, the planes of said converging surfaces intersecting on a Vertical line, said converging surfaces providing for the positioning of Valves of different sizes having heads and stems of widely different, diameters.

GLENN C. WILI-IIDE.

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