US2338509A - Grinding machine - Google Patents

Description

Jan. 4, 1944.

E. A. HALL ETAL GRINDING MACHINE Filed Jan. 19, 1943 2 Sheets- Sheet 1 TIE-2* Y? l I 17% 35 Y yaw 3: IIIHIHI v l L zag Z 7? g5 h \l I: 5/ H Q1 l Y1 L49 50 "7' fqzvzs'T A. ZZ ILL 14 4755 27" 5 EEI/JEMM Jan. 4, 1944. E. A. HALL ETAL GRINDING MACHINE Filed Jan. 19, 1943 2 Sheets-Sheet 2 W mmr E .5 A5 v T M; W

Patented Jan. 4, 1944 GRINDING MACHINE Ernest A. Hall and Robert S. Beverlin, Toledo, Ohio, assignors to The Hall Manufacturing Company, Toledo, Ohio, a corporation of Ohio Application January 19, 1943, Serial No. 472,870

12 Claims.

This invention relates primarily to eccentric valve seat grinders, and particularly to improvements on those of the type shown in U. S. Letters Patent No. 2,116,498, wherein the device is intended more particularly but not necessarily for use in grinding machines of the multiple spindle type.

In the device illustrated. in said patent, the drive or body shaft and the grinding wheel carrying spindle are each divided into universally jointed inner and outer sections, and the means which communicates eccentric movement to the grinding wheel around the pilot axis is included in part in the inner shaft section so that rotation of the shaft imparts revoluble movements to an eccentric portion of the upper spindle section relative to the shaft axis. This is found objectionable in many cases of use of the device in connection with multiple spindle type machines and also in the individual use of the devices.

An object of the present invention is to obviate said objections by providing a device of the type and character shown in said patent wherein the means for imparting eccentric movements to the grinding wheel, or other tool, about the pilot axis is confined to the outer shaft and spindle sections, thereby permitting the inner sections of the two parts to remain stationary during operation so far as any revoluble or eccentric movement thereof is concerned.

Other objects and advantages of the invention will be apparent from the following detailed description, and from the accompanying drawings, in which- Figure 1 is a central longitudinal section, with parts in full and parts broken away, of a device embodying the invention; Fig. 2 is an enlarged elevation, partly in central section, of the joint portion of the shaft member; Figs. 3, 4, 5 and 6 are perspective views of several of the joint members of the shaft; Fig. '7 is a cross-section on the line 1-1 in Fig. 1; Fig. 8 is a side elevation of the flexible drive joint portion of the spindle; Fig. 9 is a detail showing a different means for connecting the shaft and pilot, with their axes in inclined relation, and Fig. 10 illustrates the use of the device for flat seat grinding.

Referring to the drawings, I designates a section of an engine cylinder block, 2 a valve seat in said block, which may be either flat or tapered, 3 a valve stem guide, 4 a pilot mounted in said guide and projecting at its upper end through and above the seat, and 5 a grinding wheel in grinding relation to the valve seat.

The means embodying the invention includes a center shaft or body member A, which comprises an upper section 6 and a lower section 1, and also includes a grinding wheel driving spindle 8 mounted on said shaft and which likewise comprises an upper section 8 and a lower section 9 mounted, respectively, on the shaft sections 5 and i. The shaft and spindle sections are connected together to have respective driving coaction and at the same time to permit the lower sections 1 and 9 to have both universal angular or tilting and lateral sliding movements with respect to the upper sections, whereby to permit an associated grinding means to accommodate itself to an out-of-true variance within limits of a valve seat to be ground and an associated guide pilot.

The upper section B of the shaft A is journaled in any suitable stationary part It of the associated grinding machine if used in connection with such a machine, and is driven from its upper end in any suitable manner, not shown. The shaft section 8 is provided in its lower end, or that adjacent to the section I, with a longitudinally extending bore 12 which is concentric to the axis of the section B.

A tubular plug I6 is threaded into the lower end of the bore l2 and carries at its outer end a drive coupling member ll of tubular form, the upper or inner end of which is inwardly flanged over a shouldered enlargement on said plug, while its lower or outer end is outwardly flanged and threaded in the upper end of a sleeve It, the lower end of such sleeve being extended a distance below the member I1 and provided with an inwardly extending annular flange I9. A lock nut 23 threads on the member ll above its lower end flange and is adapted to have engagement with the adjacent end of the sleeve E8 to lock the members I1 and H3 in assembled relation. The member ll, which is driven by the shaft section 6 through a key Il forms one member of a drive coupling joint, in the present instance of the Oldham type, disposed between the shaft sections 6 and I. The sleeve I8 serves as a housing part around such coupling.

The adjacent ends of the shaft sections 6 and I are spaced to permit the positioning of said drive coupling therebetween, and a member 2| of this coupling is mounted on the inner end of the shaft section I and held thereto by a lock nut 22. The member 2| is of sleeve-form with its lower end restricted for clamping to the shaft section I and with its free end projected into the sleeve l8 and outwardly flanged to loosely engage over the sleeve flange iii in a manner to permit limited relative rocking and lateral shifting movements thereof. A floating coupling ring 23 is interopsed between the spaced ends of the members i? and El and has alternatel disposed lugs at opposite sides thereof, as shown in Fig. 4, which enter respective notches in the ends of said coupling members. t is thus apparent that the coupling connection between the shaft sections ii and l imparts rotation from one to the other and at the same time permits the outer section 7 to have not only angular or rocking movements relative to the section 5, but also to have lateral bodily shifting movements relative to such section so that the axis of one section may be moved out or register with that of the other section. This enables the shaft section 1, which is intended to receive and have centering engagement with a pilot, to accommodate itself to the position of such pilot which may be tilted with respect to the axis of the shaft section 6, or may be positioned so that its axis is out of coinciding or intersecting relation to the axis of the section 6, or both of such conditions may be present.

The spacing means for the inner ends of the two shaft sections 8 and i includes a half spherical joint member 26 which has its spherical surface facing outwardly or toward the shaft section 1 and seating on the internal spherical face of a ring 2? mounted on the inner end of the shaft section '5. This spacing means also includes a flat disk member 28 which seats at one side in a concentric recess in the adjacent end of the coupling member I? and at its opposite side on the fiat surface of the spherica1 joint member 26. It is thus apparent that the shaft sections may have relative angular or rocking movements about an axis concentric to the half spherical member 2% and may also have relative transverse shifting movements to place their axes into or out of registering relation by the transverse sliding movements of the joint members 26 and 28, one on the other.

The shaft section I, which is hollow, has a busing 3i) threaded into its upper or inner end and projected a sufficient distance above the inner end of the shaft section 7 to enter and center a lock washer ti on the shaft section end. This Washer has spurs extending therefrom into notches in the adjacent side of the lock nut 22. The spherical ring seat 2! rests on this Washer. The bushing 3B is internall threaded to receive and form an anchor for a threaded stem 3%, which stem projects upward from the bushing through registering enlarged openings in the joint members and 28. The stem 34 extends through the lock washer 3i and has flattened sides in coaction therewith to prevent a relative turning thereof. A link 35 is engaged at its lower or outer end to the upper or free end of the stem 34 and extends up through the tubular plug 15 and into the inner end portion of the bore i2 where it is attached to a plunger St in said bore. A coiled expansion spring 31 is disposed in the bore I2 between the plunger 35 and adjacent end of the plug it and exerts an upward pressure on the link 35 and stem 35 to hold the shaft section l up in proper relation to the shaft section 6 and to hold the joint parts 25 and 28 to their respective seats and in close sliding relation to each other. It is thus apparent that the shaft section I is driven by the shaft section 6 through the intermediate joint, and that the section I is permitted to not onl have universal rocking or angular movements relative to the se tion 5, but also is permitted to have a transverse shifting movement relative to such section due to the sliding coaction of the joint members and 2% and the manner of engagement of the Oidhain joint members ll, 2! and 23, whereby the section i may assume any desired position within predetermined limits to accommodate the axis of the pilot receiving bore 4!? to the fixed axis of the pilot 4 irrespective of the position of the axis of the shaft section 6.

The drive section 8 of the spindle B is mounted concentrically on the shaft section 6 on upper and lower sets of ball bearings it and 55, respectively, which are held in spaced relation on the shaft section by a bushing ll interposed between the outer races thereof and mounted in the spindle section 8. The upper end of the spindle section 8, in the present instance, is shouldered over the outer race of the upper ball set 45, and its lower end, below the ball set dd, is enlarged to form a housing 48 to freely receive the joint members between the shaft sections 5 and l. A ring 49 threads into the upper or inner end portion of said enlargement in engagement with the adjacent end of the outer race of the ball set 36 in opposition to the bushing 41, and this ring is internally notched to facilitate turning by use of a suitable tool.

The outer spindle section 9 is rotatably mounted on the shaft section "I on inner and outer sets of ball bearings 59 and 5! which are concentric to the axis of longitudinal center of the shaft section and are spaced apart by a sleeve 52 mounted on the shaft section, which has its ends in engagement with the inner race rings of the respective bearings. A shoulder 53 on the shaft section I engages the inner ring of the outer ball bearing set 5! in opposition to the sleeve The spindle section 9 shoulders over the outer race ring of the ball bearing set 5i? and has its outer end projecting beyond the ball bearing set 5! and threaded to receive the hub 55 of the grinding wheel 5.

The adjacent end portions of the spindle sections 8 and 9 are formed, in the present instance, with outwardly projecting annular flanges 55 and 5?, respectively, and the flange 5! has two drive pi is 58 projecting therefrom toward the other flange, one at each side of its axis. A similar pair of pins 59 project from the flange 56 toward the flange 51 at opposite sides of and in spaced relation to each pin 58. Each pin 59 of a pair is yieldingly connected to the adjacent pin 58 by a respective coiled contractile spring 8%, the tension of which springs is substantially the same so that the pins 58 are normally held in centered relation with respect to the associated pins 59. This provides a floating connection between the two sections and permits a yielding driving of one spindle section by the other and also allows for any relative tilting or adjusting movement of one section relative to the other. In addition to the yielding driving connection between the spindle sections just described, the section 3 has drive pins 5! projecting from its flange 56 at. each side of its axis and entering respective sockets 82 in the flange said sockets being larger in cross-section than the pins iii, so that positive driving action does not take place until the pins have moved a distance sufficient to take up any lost motion space between them and the socket walls, the pins being normally held in neutral position within the sockets by the action of the springs 65. It is thus apparent that .while a positive driving action may take place between the pins 6| and the lower spindle section 9, the shock of the initial engagement of the pins with the socket Walls of the section is absorbed or lessened to a considerable extent by the springs 60 and also that the drive normally is through such springs unless considerable resistance is encountered.

The spindle B is intended to be driven at high speed, in the present instance, through a spur gear 65 on its upper end, from any suitable drive means (not shown). This gives a high speed grinding action to the grinding wheel 5. The speed of driving of the shaft is slow so that in the case of eccentric grinding for which the present device is adapted, as hereinafter described, the point of contact of the grinding wheel with the valve seat is caused to progressively travel around the seat during the grinding action, as well understood in the art.

In order to adapt the present device for eccentric grinding, the shaft section 1, in the present instance, has the spindle receiving portion 48 of its bore disposed with its axis inclined slightly with respect to the axis of the shaft section with the point of intersection of the two axes coinciding substantially with the center of the spherical joint members 28 and 21, such point being indicated at c in Fig. 1. The divergence of the two axes is slight, as will be noted by the dotted axial lines a and b in Fig. 1. This divergence is sufiicient, however, to slightly tilt the grinding wheel with respect to the valve seat and to cause it to have grinding coaction with one side only of the seat, which point of engagement progresses therearound as the shaft is rotated. It is thus apparent that by mounting the wheel carrying spindle section 9 on the shaft section 1 in concentric relation thereto, and by making the spindle receiving bore of the shaft section tapered as described with respect to the wheel axis, the advantages of the eccentric mounting disclosed in said former Patent 2,116,498 are obtained as well as some additional advantages not possible by such former construction. The additional advantages reside primarily in having the eccentric movement entirely restricted to the outer section of the device and in disposing the axis of rotation of the grinding wheel at a slight angle to the pilot axis. The importance of this latter feature is to permit a greater range of use of the device in connection with the grinding of valve seats of different characters and tapers. For instance, in the use of the device of said former patent, where the axes of the pilot and grinding wheel are parallel, it is found impracticable to grind a flat valve seat, whereas with the present arrangement the inclination of the wheel axis to that of the pilot permits the grinding of a flat valve seat, as shown in Fig. 10.

In the use of a grinding device embodying the present invention, and particularly when used in connection with a multiple spindle grinding machine, the lower shaft and spindle sections of the respective devices are mounted down over the respective guide pilots of the work and said lower sections of each device are permitted to adjust themselves to the particular pilot with which associated and, due to the jointed connection between the upper and lower sections of the device, without disturbing or placing objectionable lateral strain on the upper driving sections of the device. At the same time, the lower shaft and spindle sections of each device are positioned with their common axis in slightly inclined or diverging relation to the axis of the coacting pilot with the point of intersection of the diverging axes falling at approximately the pivotal center of the lower or adjustable section of the device. It is apparent that the driving of the shaft at a low speed while the grinding wheel is driven at a high speed causes the point of grinding engagement of the wheel with the valve seat, which is at one side only of the wheel axis, to progressively travel entirely around the seat so that uniform grinding is effected.

While the device shown has been particularly described for use in connection with a multiple spindle grinding machine, it will be understood that its use is not limited to grinding machines, and particularly valve seat grinders, but may be used in any connection for which it may be adapted and also that the device may be used separately from such a machine and as an individual unit in either grinding or other operations for which it may be adapted.

It will also be understood that while the sections of the shaft A and spindle B for convenience have been referred to as upper and lower sections, inasmuch as the devices are usually used above the work, it is not intended or desired by such description to restrict the device to use above the work. The upper and lower shaft and spindle sections also may be considered as inner and outer sections, respectively, but this terminology is not used in the specification, as it tends to cause confusion where reference is made to the inner and outer end portions of the respective parts.

In Fig. 9 the inclined feature of the axes of the tool shaft and work pilot, when in connected operating relation, is shown as effected by the provision of a cylindrical sleeve 19 mounted either in an axial bore of the shaft section 1, or on the pilot 4 and having its pilot receiving bore inclined to give the desired inclination to said shaft section relative to the pilot axis when the device is in operation. In some cases this form might be preferable to that shown in Fig. 1, as it obviates the necessity of providing an inclined bore in the shaft section, which might be a more difficult and expensive operation than providing a sleeve 19 with an inclined bore. It will be understood that this feature comes within the terminology of the claims which call for the outer shaft section as having provision for centering engagement with a stationary guide pilot with the axes of said section and pilot diverging from a point substantially concentric to the rocking center of the section.

While this invention is not limited to any specific construction, arrangement or form of the parts, it will be understood that it is capable of numerous modifications and changes without departing from the spirit of the claims.

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

1. In a device of the class described, a rotatable shaft having inner and outer sections, an Oldham type of drive joint between said sections permitting universal rocking and predetermined relative lateral shifting movements of the sections, a spacing means for the inner ends of the sections including a spherical seat on the inner end of the outer section, a spherical member engaging said seat and having a substantially flat opposing face, and a second member seating on the fiat face of said first member and laterally shiftable relative thereto, means tying the shaft sections together through said joint members, said outer section having a pilot receiving socket therein which is inclined to and intersects the axis of such section at a point adjacent to the rocking center of said joint and diverges therefrom toward the outer end of such section, a spindle including inner and outer sections rotatably mounted respectively on said inner and outer shaft sections concentric to their axes, and a grinding Wheel carried by the outer end portion of the outer spindle section with its axis concentric to the shaft section axis.

2. In a device or" the class described, a slow speed rotatable shaft having separate inner and outer sections connected end to end for relative universal movements to permit the outer section to shift relative to the inner section to accommodate itself to a guide pilot, a high speed spindle having inner drive and outer driven sections rotatably mounted on said inner and outer shaft sections, respectively, concentric to their axes and including a floating driving connection between their adjacent ends, and a grinding wheel carried by the outer end portion of said outer spindle section concentric thereto, said outer shaft section having a guide pilot receiving bore the axis of which intersects the shaft section axis adjacent to the center of the connection between the shaft sections and diverges therefrom outwardly from said center toward the outer end of the outer shaft section.

3. In a device of the class described, a slow speed rotatable shaft having inner and outer sections and including an end thrust joint between said sections having a spherical concave seat on the outer section and a transverse sliding seat on the inner section together with a tying means between the sections, and also including a drive joint between the sections outside said end. thrust joint permitting relative universal rocking and transverse shifting movements of the sections, said outer section having a bore in its outer end for receiving a stationary work pilot with the axis of said bore inclined to and intersecting the axis of the section at a point substantially coinciding with the center of the spherical joint between the sections with the outward divergence of the axes toward the outer end of said outer section, a high speed spindle mounted on said shaft having inner and outer sections driven one from the other through a floating joint and mounted respectively on the inner and outer shaft sections concentric to their axes, and a grinding wheel carried by the outer spindle section concentric to its axis and adjacent to the outer end of said outer shaft section.

a. In combination, a valve seat grinding tool and a pilot for holding the tool in operative relation to a valve seat to be ground, said tool including a shaft and a grinding wheel carrying spindle mounted one on the other for relative concentric rotation and each having inner and outer sections jointed at their inner ends for relative universal rocking movements and. the outer shaft section and the pilot having interengaging connection in use with the turning axis of the outer shaft section inclined to the pilot axis at approximately the joint center of the two shaft sections with the divergence of said axes away from said center toward the outer end of the outer shaft section whereby the axis of the wheel carrying portion of the spindle has an orbital movement around the pilot axis during grinding.

5. In a device of the class described, a tool carrying spindle having inner and outer sections driven one from the other and connected for relative universal rocking movements, 2. tool carried by said outer spindle section at its outer end relative to the rocking connection of the sections, said outer section having provision at its tool carrying end for centering engagement with a stationary guide pilot about which the section may turn with the axes of said section and pilot diverging outwardly from a point substantially concentric to the rocking center of the sections toward the tool carrying end of the section whereby the degree of eccentric throw of said outer section relative to the pilot axis increases outwardly from such point toward its tool carrying end.

6. In a device of the class described, a spindle having an inner drive section and an outer driven tool carrying section, a wheel like tool carried by said outer section at its outer end, and a connection between said sections including a universal rocking and universal transverse shifting joint enabling one section to be driven by the other irrespective of any predetermined out-ofline relationship of the axes of the two sections, said outer section having provision for centering engagement with a stationary guide pilot about which the section may turn with the axes of said section and pilot diverging outwardly from a point substantially concentric to the rocking center of the sections toward the tool carrying end of the outer section whereby the degree of eccentric throw of said outer section relative to the pilot axis increases outwardly from such point toward its tool carrying end.

7. In a device of the class described, a spindle having an inner driving section and an outer driven tool carrying section connected for relative universal rocking movements, a tool on the outer end portion of said outer section, and a guide part in said outer section having provision for receiving a guide pilot and to turn thereon with the axes of said section and pilot diverging outwardly from a point substantially concentric to the rocking center of the section toward the tool carrying end of the section whereby the tool axis has an orbital movement about the pilot axis when said guide part is turned.

8. In a device of the class described, a spindle divided into an inner driving section and an outer driven section connected end to end for relative universal rocking movements, a work treating tool on the outer end portion of the outer section, and means rotatable in said outer section and having provision for centering engagement with a guide pilot with the axis of rotation of said means and that of the pilot diverging outwardly from a point adjacent to the point of connection of the spindle section toward the tool carrying end of the outer section whereby the tool axis has an orbital movement about the pilot axis when said means is rotated.

9. In a device of the class described, a spindle divided into an inner driving section and an outer driven section connected for rotary universal rocking movements, a grinding wheel carried by said outer section in outwardly spaced relation to its rocking connection, and a rotatable shaft part concentric to and about which said outer section rotates and having in its outer end a pilot receiving bore with its axis diverging outwardly from that of the shaft part at a point adjacent to the inner end of the outer spindle section and toward the wheel carried thereby whereby the grinding wheel axis has an orbital movement about the axis of said bore when said shaft part is rotated.

10. In a device of the class described, a spindle divided into an inner drive section and an outer driven section connected. for relative universal rocking and other movements, a work treating tool carried by said outer section at its outer end, and a rotatable shaft part journaled in said outer section With its axis of rotation concentric to that of the outer spindle section, said shaft part having a work pilot receiving bore extending inwardly from its outer end with its axis inclined to the axis of rotation of the part and intersecting the latter adjacent to the rocking center of the outer spindle section with the divergence of said axes outwardly from a point substantially coincident with said rocking center and toward the tool carrying end of the outer section.

11. In a device of the class described, a spindle having inner and outer sections driven one from the other and connected for predetermined rocking and transverse shifting movements of the outer section relative to the inner section, a grinding wheel carried by said outer section at its outer end, a shaft forming a concentric mount for each of said sections and jointed between said sections for relative universal rocking and other movements, said shaft being rotatable at a speed different from that of the spindle, the portion of the shaft carrying the outer spindle section having a guide pilot bore extending therein from its outer end with its axis slightly inclined to and intersecting the axis of rotation of the outer spindle section at a point adjacent to the rocking center of the shaft and spindle sections, the divergence of the axes being outwardly from said point toward the tool carrying end of the outer section.

12. In a device of the class described, a rotatable shaft having inner and outer sections connected for relative universal rocking movements, a spindle having jointed inner and outer sections rotatably mounted respectively on the inner and outer shaft sections, a grinding Wheel carried by the outer spindle section at its outer end, said outer shaft section having a bore extending inwardly from its outer end for closely receiving a stationary guide pilot, said bore having its axis inclined to and intersecting the axis of rotation of the outer spindle part at a point coinciding substantially with the rocking center of the shaft sections, the divergence of the axes being outward from such point toward the Wheel carrying end of the outer spindle section.

ERNEST A. HALL. ROBERT S. BEVERLIN.

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