US2486750A - Machine for and method of forming bodies by grinding - Google Patents

Description

I A. C MASON MACHINE FOR AND METHOD OF FORM Nov; 1, 1949 BODIES BY GRINDING Filed Jan. 28, 1948 4 sheets-sneak 1' wall/M NEY Nov. 1, 1949 A. c. MASON 2,486,750

MACHINE FOR AND METHOD OF FORMING BODIES BY GRINDING Filed Jan. 28, 1948 4 Sheets-Sheet 2 INVENTOR BY U V35 ATTO R N EY 1949 A. c. MASON 2,486,750

MACHINE FOR AND METHOD OF FORMING BODIES BY GRINDING Filed Jan. 28, 1948 4 Sheets-Sheet 3 *MPPPMMPPPM Nov. 1, 1949 A. c. MASON ,4 ,7 MACHINE FOR AND METHOD OF FORMING BODIES BY GRINDING Filed Jan. 28, 1948 I 4 Sheets-Sheet 4 INVENTOR 609L977 (11%25'01! A TTORNE Y Patented Nov. 1, 1949 MACHINE FOR AND METHOD OF FORMING BODIES BY GRINDING Arthur 0. Mason, Wayne Township, Passaic County, N. J

Application January 28, 1948, Serial No. 4,836

32 Claims.

This invention relates to a centerless grinder of improved construction which makes it possible to produce a plurality of similar bodies from an elongated work-piece fed thereto continuously along its axis. The invention also relates to a novel method of grinding, wherein such workpiece is fed continuously along its axis and is progressively formed into a plurality of similar bodies by grinding means acting thereon.

The invention has among its objects the provision of an improved centerless grinder of such construction that it feeds an elongated workpiece continuously thereinto and progressively forms a plurality of similar bodies therefrom.

A further object of the invention lies in the provision of a grinder of the type above indicated in which the grinding wheel is helically grooved and the regulating or controlling wheel axis is skewed relative to the axis of the grinding wheel to produce axial feeding of the work-piece fed therebetween.

A still further object of the invention, in its preferred embodiment, resides in the provision of a centerless grinder of the type described of improved simplified construction, such grinder being further characterized by the ease and speed of its operation in producing finished bodies.

Included among the objects of the invention is also the provision of a novel method of grinding wherein in one continuous operation, involving feeding an elongated workpiece continuously along its axis, a plurality of similar bodies are formed therefrom.

Yet a further object of the invention lies in the provision of a method of the type indicated in which the elongated work-piece is fed axially by being fed between the grinding wheel and the regulating wheel, the axes of which are skewed,

the grinding wheel being helically grooved, and the angle of skew being related to the helical angle of the grooves of the grinding wheel whereby the ground cuts in the work-piece register or mesh with the lands on the grinding wheel as the work-piece progresses past such wheel, there finally being produced a plurality of separate similar bodies.

These and further objects of the invention will be more readily apparent in the following description of preferred embodiments of the grinding apparatus and method of the invention,

For purposes of illustration the invention will be described in its preferred embodiment in connection with its use in the forming of spherical beads by grinding them from plastic rods. It is to be understood, however, that the apparatus and the method or the invention are capable of use in forming bodies which are cylindrical or an appreciable portion of the length of which is cylin drical, as well as spherical articles, from rods 01 elongated cylindrical work-pieces, that such workpieces may be of any desired composition, and that such articles may be employed for any desired purpose.

In recent years most of the spherical beads employed in the costume jewelry industry have been formed by grinding. The method most widely used heretofore has involved the grinding of the beads in a centerless grinder from a rod or partially formed multiple blank. The grinding wheel in such grinders has a plurality of spaced circumferential grooves with interposed lands, both grooves and lands being located in planes at right angles to the axis of the wheel. Such rods or multiple blanks, of lengths roughly corresponding to that of the grinding wheel, have been fed singly into the grinder, the regulating wheel then being progressively fed toward the grinding wheel so that the rod or blank is first severed and the severed sections are then finished to spherical shape.

It will be appreciated that such method is disadvantageous since the grinding operation is discontinuous and numerous delays due to feeding of the stock to the grinders are involved. Furthermore, since multiple partially formed blanks are usually employed, the total cost of making the beads includes not only the grinding operation but also the blank forming operation.

Use of the apparatus and method of the present invention results in the much faster and thus more economical production of a plurality of similar bodies, of which spherical beads are typical. The grinding operation is continuous and thus the machine is not idle during feeding operations. For a given diameter of stock the regulating wheel is fixed relative to the grinding wheel and thus no adjustment of the machine is necessary throughout a run. The stock utilized for forming the beads or other spherical objects is economical, easily obtained, cylindrical stock, either solid or pierced. When beads are made, it is preferred to employ stock which is in effect a heavy-walled tube, so that no piercing of the individual beads is necessary later. In the further description of the invention and in the claims, such cylindrical stock, either solid or pierced, will be referred to as rod.

The invention will be more readily understood by reference to the accompanying drawings in which Fig. 1 is a view in side elevation of the grinding machine from one side thereof;

Fig. 2 is a View in side elevation of the top part of the machine from the opposite side thereof;

Fig. 3 is a fragmentary view in plan of the machine showing the grinding wheel and the reg ulating wheel of the first embodiment in their operative relationship;

Fig. 4 is a somewhat schematic view in side elevation of such wheels, showing the angle of skew between the axes of the grinding wheel and the regulating wheel;

Fig. 5 is a view in vertical section through the machine, the section being taken along the line VV in Fig. 1;

Fig. 6 is a view in vertical section through the machine in a plane parallel to the axis of the grinding wheel, the section being taken along the line VI--VI in Fig. 2;

Fig. 7 is a fragmentary view in vertical section, the section being taken along the line VII- VII in Fig. 6;

Fig. 8 is a somewhat schematic view in plan of a second embodiment of the grinding wheel, such wheel being of hour-glass shape in over-all contour, and of a cylindrical regulating wheel cooperating therewith;

Fig. 9 is a View similar to Fig. 8 of a third embodiment of the combination of grinding wheel and regulating wheel, the grinding wheel being cylindrical in over-all shape and the regulating wheel being of hour-glass shape.

Fig. 10 is a fragmentary view in plan of a grinding wheel and a regulating wheel cooperating therewith for grinding a plurality of cylinders from an elongated work-piece;

Fig. 11 is a view in perspective of a cylindrical body ground by the apparatus of Fig. 10;

Fig. 12 is a fragmentary view in plan of a further embodiment of a grinding wheel and regulating wheel cooperating therewith for grinding a plurality of bodies having mid-sections of hourglass shape from an elongated work-piece;

Fig. 13 is a view in perspective of a body ground by the apparatus of Fig. 12;

Fig. 14 is a fragmentary view in plan of a still further embodiment of grinding wheel and regulating wheel cooperating therewith for grinding a plurality of pointed bodies having cylindrical portions of substantial length thereon from an elongated work-piece, and

Fig. 15 is a view in perspective of a body ground by the apparatus of Fig. 14.

The machine illustrated embodies a main frame I forming a vertical supporting structure, the frame being enclosed by a main housing 2. Within such housing and supported on the frame, as shown in Fig. 1, is located the driving motor 4. The top of the frame, indicated at 6, in effect forms a table upon which are supported the members upon which the grinding and regulating wheels are mounted. At 8 is shown the standard rising from frame top 6 which forms the support for the grinding wheel 56. Such wheel is mounted on the arbor if] supported suitable bearings in standard 8. The arbor is driven by means of the multiple V belts i2 entrained over the multiple V pulleys M on the shaft :of motor 4 and over the multiple V pulleys It on the outer end of arbor l 0. In this instance, as indicated more clearly in Fig. 3, no outboard bearing is employed at the left-hand end of the arbor II], the arbor and the bearings in standard 8 being made suificiently rugged to support the grinding wheel accurately and free from vibration.

The regulating wheel 54, in this instance a fine grit abrasive wheel of cylindrical shape, is mounted in a supporting means so that it may be advanced toward or retracted from the grinding wheel to present a gap therebetween of the desired width. In the machine shown, such means for adiustably mounting the regulating wheel takes the form of an upstanding flange I8 fixedly mounted on one side of frame part 6 and an upstanding member 20, on the other side of such frame, parallel to member l8 and movable on the frame toward and away from the axis of the grinding wheel. Member I8 is provided with a horizontal hole 22 parallel to the axis of the grinding wheel and member 20 is provided with a hole 24 which may be aligned therewith. The regulating wheel support 26, which is provided at its bottom with the two depending parallel ears 3!] and 32, is pivotally mounted on members l8 and 2E} by means of the pivot rod 28, which extends through such ears and through holes 22 and 24. Such construction is shown most clearly in Figs. 6 and 7. The inner surface of hole 22 is made curved, as shown, snugly to receive within it the sleeve 34, mounted on rod 28. The outer surface of sleeve 34 is curved on a radius smaller than that of the curvature of the inner surface of hole 22. Such construction allows the rod 28 and thus mounting 26 to be accurately held at their right-hand ends (Fig. 6), while their lefthand ends are moved toward and away from the grinding wheel.

Such adjustment of the left-hand ends of the rod 28 and regulating wheel mounting is provided by mounting member 20 slidably on the upstanding flange 36, the upper surface of which provides a guideway, on the frame of the machine and by providing means which permits accurate adjustment of member 20 along such support 36. Such means is provided by the bracket 38 affixed to the side of the frame 6, such bracket having its upper part in the form of an inwardly projecting ear 40. An adjusting screw 42 passes freely through a hole in the ear and is retained against axial movement with respect thereto by means of the check nuts 48. The forward end of screw 42 is threadedly received in the bore 44 in member 20, the bottom surface of which is formed of a shape complementary to the guideway on member 36, and which may be held firmly and accurately down upon member 36 by means of the studs 52 which extend through vertical slots 50 in member 20 and into part 36. It will be seen that when studs 52 and check nuts 48 are loosened, and the adjusting screw 42 turned by means of the knob 46, member 20 may be advanced toward or retracted from the grinding wheel in the desired amount, thereby adjusting the angle which the axis of the regulating wheel makes with respect to the axis of the grinding wheel, as viewed in plan. Such angle, shown at a in Fig. 3, is hereinafter termed the angle of approach. When such desired angle of approach is attained, studs 52 and check nuts 48 are tightened.

The mounting of the regulating wheel is such that it also permits skewing of the axis of the regulating wheel relative to the axis of the grinding wheel, as viewed in side elevation, as shown in Figs. 4 and 6. Such further adjustment of the regulating wheel is secured by making the upper portion 58 of the regulating wheel support, which also incorporates therein a guard for the wheel and the bearings 60 for the wheel shaft 62 therein, separate from and pivotally adjustable on the main support 26. Part 26 is provided at the left, in Fig. 6, with an upstanding curved slot 86 in member 26, An adjusting stud 88 is provided on the upper edge of member 26 at the right, the head of such stud contacting an abutment surface on member 58, as shown. When stud 84 is loosened, member 58 and the regulating wheel 54 carried thereby may. be angularly adjusted in a vertical plane so that the desired angle of skew between the grinding and regulating wheels is obtained. Thereupon stud 84 is tightened to maintain such adjustment. As the result of such construction, the angle which the axis of the regulating wheel makes with the axis of the grinding wheel may be independently adjusted in both horizontal and vertical planes. The angle of skew determines the effective feeding thrust upon the rod being ground, which travels parallel to the axis of the grinding wheel, exerted by the regulating wheel. The right-hand edge of flange B0 is provided with a plurality of equally spaced horizontal projections 85 disposed on a circle centered at stud 82, such projections together with a similar projection (not shown) on member 26 confronting and spaced from them, serving as a ready indication of the amount of the skew angle.

The regulating wheel 54, which may be made, as above described, in the form of a cylindrical abrasive wheel, is driven in such direction that its surface travels upwardly in the grinding zone confronting the grinding wheel. The grinding wheel surface travels downwardly in the grinding zone, the rod being ground turning at the same surface speed as the regulating wheel and counter-clockwise, as shown in Fig. 3. The grinding wheel has a surface speed somewhat in excess of, and is usually several times as great as, that of the regulating wheel. The driving means for the regulating wheel takes the form of the cross-shaft 68 through the portion 6 of the frame of the machine, such shaft being connected to arbor Ill through the medium of the sprocket I6 on the arbor, the sprocket I2 on one end of the cross-shaft, the chain 74 entrained over sprockets I2 and I6, as shown in Fig. 1, and by means of the sprocket III on the other end of the shaft, the sprocket 64 on the regulating wheel shaft, and the chain 66 running over sprockets 64 and It, as shown in Figs. 2 and 6.

It will be appreciated that the gap between the regulating wheel and the grinding wheel in the grinding zone may be adjusted by pivoting the regulating wheel carrier 26 about rod 28 toward and away from the grinding wheel. Means 26 is thrust toward the grinding wheel by an adjustable rear abutment means which includes the standard 90 bolted to the machine frame, such standard carrying a main horizontally directed cylindrical body 92 on its upper end. Projecting from the forward end of such body, and mounted in a horizontal bore therein, is the plunger 94 which contacts the rear abutment surface 95 on the regulating wheel carrier. Plunger 94 is yieldably thrust to the left, in Fig. 2, by means of the adjusting screw I00, which is provided with the operating knob I02, a stiff helical spring 98 being interposed between the inner end of the plunger and the inner end of the-screw. Such yieldable abutment constitutes a safety means, since it allows the regulating wheel to yield and move away from the grinding wheel should work jam therebetween and produce a wedging force in excess of a predetermined desired amount.

The degree of approach of the regulating wheel toward the grinding wheel is determined by the micrometer stop means indicated generally at I04. Such means, which is mounted upon standard 8 as shown, includes a micrometer plunger I06 which contacts the abutment surface I08 on member 58 of the regulating wheel mounting. The plunger is mounted in the micrometer barrel IIIl so that .upon rotation of the barrel the plunger may be advanced or retracted. The barrel is provided with a graduated flange II2 which cooperates with the index H4 on standard 8. Knob H6 on the barrel provides for its ready rotation.

Flange II2 of the micrometer may, if desired, be so calibrated that with a given diameter of grinding wheel and regulating wheel the gap between them may be read directly from the micrometer. The micrometer is usually set with the plunger 94 backed off, after which the regulating wheel carrier is advanced toward the grinding wheel and screw I00 is operated to thrust plunger 94 thereagainst with a predetermined force.

The elongated rod I 40 which is ground into spherical bodies by the device rests upon an elongated anvil or work-supporting blade which extends between the lands of the grinding wheel and the surface of the regulating wheel longitudinally thereof in the grinding gap between them. Support for such anvil I26 is provided in part by the bracket I I8, at the left in Fig. 5. Such bracket has a lower vertical flange I20 attached to the frame part 6 by means of the studs I22 and a top vertical flange I24, extending parallel with the axis of the grinding wheel, to which the anvil is bolted. The right-hand end of the anvil is likewise supported from the frame of the machine through the medium of means I28 which is in the form of a trough integral with-standard 8. Spaced vertical slots I30 are provided in the forward wall of such trough, and through such slots extend studs I32 screwed into the anvil. It will be apparent that vertical adjustment of the anvil may be made by loosening the nuts on studs I32 and on the stud I36, which attaches its lefthand end to bracket I I8, adjusting the anvil vertically, and angularly if necessary, the studs then being tightened to retain the anvil in the desired adjusted position. Ordinarily the anvil is located so that the rod I40 lies slightly above the location of closest approach of the grinding and regulating wheels and so that the axis of the rod lies parallel to the axis of the grinding wheel. The portion I31 of the anvil between the grinding and regulating wheels is hollow ground along both sides to allow a close fit between the anvil and the wheels.

The rod to be ground is fed to the machine in a direction into the paper of Fig. 2, and from the left to the right in Fig. 5. To insure accurate positioning of the entering end of the rod, an L-shaped hold-down member I38 is provided on the entering side of the machine as shown in Fig. 2 so that the rod must be in contact with the anvil as it enters. To prevent the portion of the rod in the grinding zone of the machine from jumping out of position, a depending top guide I42, supported as shown on the guard for the grinding wheel, is provided, the bottom surface of guide I42 being as closely adjacent the work-piece as possible. The grinding wheel 56, which when soft plastic materials are being ground is preferably of the ceramic bonded alumina type with an open structure, is provided with helical grooves I44 and interposed lands I 46. Preferably such grooves are of uniform cross section throughout the length of the wheel, and have a constant helical angle 0. Such grooves, in the embodiments shown, are in the form, in cross-section, of a half circle. The angular relationships between the grinding and regulating wheels will be apparent from a considerationof Figs. 3 and 4. As shown in these figures, the axis AB of the grinding wheel is horizontal. When viewed in plan, as in Fig. 3, the axis C--D of the regulating wheel approaches axis A--B of the grinding wheel, in a direction from left to right, the angle a measuring the angle between such axes. By reason of such angle, that is, the angle of approach, the entering rod is lightly gripped by the left-hand ends of the two wheels and the rod is ground to increasingly greater depths by the lands I46 as the rod travels toward the right. The right-hand ends of the two wheels are so spaced that the ground bodies become separated from the rod at a point spaced from the right-hand ends of the wheels, such as that designated I41.

In Fig. 4 the two wheels are shown as they appear in side elevation. Axis C--D of the regulating wheel is disposed at an angle 1), the skew angle, with respect to the axis A--B of the grinding wheel. Such angle of skew is necessary in order to aid in the progress of the work-piece through the machine. Angle b, which will always be as great as, or greater than the angle c, is so chosen relative to the diameter of the rod being ground, the helical angle of the grinding wheel, the coefficients of friction between the rod and the regulating wheel and between the rod and the grinding wheel, and the peripheral speeds of the two wheels with respect to each other, that the rod is fed between the wheels at such speed in an axial direction that the progressively deeper cuts produced thereon by succeeding lands remain accurately in mesh or register with such lands. When such condition is attained, it will be seen that the rod will be cut progressively in the intermediate zone I49, until at some point, such as M1, the portions of the rods between cuts become separated.

At such positions, as shown in Fig. 3, the separate bodies I5I will have been ground to approximately spherical shape. When the bodies are freed from the main body of the rod they are free to rotate continuously about universal axes, so that further travel longitudinally of the grinding zone through the space of two or three helical grooves of the grinding wheel will have brought them to a perfectly spherical shape and into finished polished condition in which condition they are discharged from the grinding zone as shown at I53. Such finished beads I53 fall into the trough I28, from which they travel downwardly to a container (not shown).

It will be apparent that by a suitable change in the cross-sectional shape of the grooves in the grinding wheel a plurality of bodies which are solids of revolution but which have cross-sections taken along the axis of the work-piece other than circular may be produced. Such shapes include plain cylinders, and also bodies of revolution hav- 1 ing either cylindrical portions spaced appreciable distances apart or one cylindrical portion of substantial length. Such requirements are dictated by the fact that the bodies both when attached to the work-piece and when detached therefrom must be guided accurately in the grinding gap between the grinding wheel and the regulating wheel.

Figs. 10 and 11 depict, respectively, the apparatus by which plain cylindrical bodies are produced and one such resulting body. In Fig. 10 the grinding wheel is designated I10, the peripheral helical lands thereon I12, and the helical grooves between the lands, I14. The regulating wheel is designated I16. The elongated work-piece I18 is shown being ground at a zone adjacent the entering zone. Successive lands I12 grind the workpiece more deepl on each revolution of the workpiece as the latter travels to the right. After the cylindrical bodies have been severed from the work-piece and have traveled additionally through the space of several lands, they emerge from the grinding zone accurately sized and finally polished. One such finished cylindrical body is shown at I88 in Fig. 11.

In Fig. 12 there is shown apparatus for grinding a plurality of bodies having cylindrical end portions and an hour-glass mid-section. The grinding wheel in this embodiment is designated I82, the helical lands on the periphery of the wheel I84, and the helical grooves between such lands are designated I86. Such grooves are provided with approximatel shaped and located helical projections I88 the axial elements of which have the same shape as the shape of the elements of the mid-section of the body to be ground. The workpiece I9Il is entered in the usual manner between the grinding wheel and the regulating wheel I92, and progresses to the right while being rotated. The resulting finished body produced by the apparatus of Figure 12 is shown in Figure 13, where it is designated I94.

As above indicated, it is also possible to produce ground bodies which are pointed so long as a substantial part of their length is cylindrical. A typical body of this type is shown in Fig. 15 where it is designated I95. Such bodies may be produced by the apparatus of Fig. 14 in which the grinding wheel is designated I98, the helical lands 280, and the helical grooves between the lands are generally designated 202. Lands 288 in this instance are provided at their left edges with helically disposed projecting portions 204, the axial elements of which have the same shape as the elements of the point of the body to be ground. Work-piece 288 is engaged between the grinding wheel and the regulating wheel 208 and, as in the other embodiments, is ground to an increasingly greater depth at zones between the portions of the work-piece which are to become the ground bodies, the bodies finally being separated and finished as individual bodies in the grinding zone as in the other embodiments of the apparatus.

In the embodiments of the apparatus shown in Figs. 3, 4, 10, 12, and 14, the regulating wheel has been shown as being of cylindrical shape and the grinding wheel has been shown with the outer surfaces of its lands lying on an imaginary cylinder. Such configurations of regulating and grinding wheels is satisfactory when the angle of skew b of the regulating wheel is small, although theoretically when the axis of the regulating Wheel is not parallel to that of the grinding wheel contacts between the rod or work-piece and each of the wheels take place only at a point. The apparatus works satisfactorily, however, when the angle b is small, when both wheels are cylindrical, due perhaps to the fact that the plastic 9 material from which the beads are formed is yieldable to some extent.

When the angle b becomes appreciable or when the material to be ground is rather unyielding, it is preferred to employ the combination of grinding and regulating wheels shown in Fig. 8. The regulating wheel in that embodiment is cylindrical, and may be identical with that shown in Fig. 4. It is therefore designated by the same reference character 54. The grinding wheel I48 in this embodiment, however, is substantially in the form of a hyperboloid of one sheet, its parameters and thus its shape being chosen so that a straight line disposed at a mean angle of skew with respect to the axis of the grinding wheel will contact all the lands of such wheel. By mean angle is meant the angle usually employed for a given diameter of work-piece and helix angle 0. It will be appreciated that it may be necessary to adjust the angle of skew to a value somewhat away from such mean angle but that by proper design of the grinding wheel with a particular job in view, the actual angle b employed need not be far from the mean angle. By use of the combination of grinding and regulating wheels shown in Fig. 8, substantial or actual line contact may be maintained between the rod being ground, the regulating wheel and the grinding wheel. In Fig. 8 the helical grooves on the grinding wheel are designated I52 and the helical lands I54. The entering zone of the wheel is shown at the left at I56. The intermediate zone is designated I58 and the finishing zone I60. Separation of the beads from the rod will occur, in ordinary use, at

the boundary between zones I58 and I60.

In some applications it is feasible to obtain substantially straight line contact between the work-piece, the regulating wheel and the grinding wheel by use of the embodiment of the apparatus schematically shown in Fig. 9. In this embodiment the regulating wheel I62, instead of being an abrasive wheel as in all embodiments previously discussed, may be made, for example, of hard rubber. The regulating wheel I62 is substantially in the form of a hyperboloid of one sheet, its shape being so chosen that a straight line disposed at a mean angle of skew b with respect to its axis willcontact its surface throughout its length. The grinding wheel may be made identical with that shown in Figs. 3 and 4 and thus such wheel is designated 56 and the grooves and lands thereon I44 and I46, respectively.

In the embodiment shown in Fig. 9, it will be apparent that the entering zone I64 and the fin-- ishing zone I68 will have higher peripheral speeds than the intermediate zone I66. Thus the speed of rotation of the work-piece will lie somewhere between the speeds of rotation of the zones I64 and I68 on one hand, and I66 on the other, and slippage between the regulating whee1 and the work-piece will occur at zones at various places throughout its length. It is for this reason that a substantially non-abrasive regulating wheel is chosen in this embodiment, in order that the grinding shall be done substantially wholly by wheel 56.

Although the dishing of wheel I62 in Fig. 9, and of the surface upon which lands I54 lie in Fig. 8 has been shown as being quite marked, for ease of illustration, it will be appreciated that actually the distance by which the center of the peripheral surface of each such wheel is spaced from an imaginary cylinder containing the ends of each wheel is very small. To the eye, each such wheel, made to yield substantially line contact between it and the work-piece, as above described, will appear cylindrical. Such wheels are thus intended to be included within the term generally cylindrical used in the claims.

Although I have described and illustrated preferred embodiments of the machine for and method of forming bodies by grinding of my invention, it will be apparent that such embodiments are illustrative only and that the invention is capable of considerable variation as to details. The invention is therefore defined as to its scope by the appended claims.

I claim as new the following:

1. The method of shaping a work-piece which comprises feeding an elongated work-piece along its axis and simultaneously rotating it about such axis, and progressively removing stock from a plurality of annular zones around the axis of the work-piece as it travels, said annular zones being spaced along the length of the work-piece.

2. The method of forming a plurality of bodies which comprises feeding an elongated work-piece along its axis and simultaneously rotating it about such axis, progressively removing stock from a plurality of zones around the axis of the work-piece as it travels, said zones being spaced along the length of the work-piece, and progressively severing from the main body of the work-piece at the forward end thereof the bodies formed between such zones of stock removal.

3. The method of forming a plurality of similar bodies which comprises feeding an elongated work-piece along its axis and simultaneously rotating it about such axis so that a point on its surface travels in a helix, progressively removing stock from a plurality of zones around the axis of the work-piece as it travels, the zones being spaced along the length of the work-piece, and progressively severing from the main body of the work-piece at the forward end thereof the bodies formed between such zones of stock removal.

4. The method of shaping a work-piece which comprises feeding an elongated work-piece along its axis and simultaneously rotating it about such axis so that a point on its surface travels in a helix, and progressively removing stock by grinding operations from a plurality of annular zones around the axis of the work-piece as it travels, the annular zones being spaced along the length of the work-piece.

5. The method of forming a plurality of similar bodies which comprises feeding an elongated work-piece along its axis and simultaneously rotating it about such axis so that a point on its surface travels in a helix, progressively removing stock by grinding operations from a plurality of zones around the axis of the work-piece as it travels, the zones being spaced along the length of the work-piece, and progressively severing from the main body of the work-piece at the forward end thereof by a grinding operation the bodies formed between such zones of stock removal,

6. The method of forming a plurality of similar bodies which comprises feeding an elongated work-piece along its axis and simultaneously rotating it about such axis so that a point on its surface travels in a helix, progressively removing stock from the work-piece by presenting grinding instrumentalities thereto at a plurality of annular zones around the axis of the work-piece as it travels, there being relative movement between the work-piece and each of the grinding instrumentalities in the plane of each of the annular zones, the zones being spaced along the length 11 of the work-piece, and progressively severing from the main body of the work-piece at the forward end thereof by a grinding operation the bodies formed between such zones of stock removal.

7. The method of forming a plurality of similar bodies which comprises feeding an elongated work-piece along its axis and simultaneously rotating it about such axis so that a point on its surface travels in a helix, progressively removing stock from the work-piece by simultaneously presenting narrow grinding instrumentalities rotating about an axis fixed relative to the path of travel of the work-piece thereto at a plurality of annular zones around the axis of the work-piece as it travels, there being relative movement between the work-piece and each of the grinding instrumentalities in the plane of each of the annular zones, the zones being spaced along the length of the work-piece, and then progressively severing from the main body of the work-piece at the forward end thereof by one of such grinding instrumentalities the bodies formed between such zones of stock removal.

8. The method of shaping a work-piece which comprises feeding an elongated work-piece along its axis and simultaneously rotating it about such axis so that a point on its surface travels in a helix, progressively removing stock from the work-piece by presenting to the Work-piece an elongated grinding wheel the axis of which converges toward the path of travel of the workpiece in the direction of the latter, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of 'the groove being separated by a helical land, the land progressively engaging the work-piece at a plurality of annular zones around the axis of the work-piece as it travels, and controlling the speed of rotation of the work-piece so that there is a substantial difference in speed between the surface speed of the land and the surface speed of the work-piece.

9. The method of forming a plurality of similar bodies of revolution which comprises feeding an elongated cylindrical work-piece along its axis and simultaneously rotating it about such axis so that a point on its surface travels in a helix, progressively removing stock from the work-piece by presenting thereto an elongated grinding wheel the axis of which converges somewhat toward the path of travel of the work-piece, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, the land progressively engaging the work-piece more deeply at a plurality of annular zones around the axis of the work-piece as it travels so that after engagement between a plurality of turns of the helical land and the work-piece the latter is engaged between the annular zones and ground by the surface of the grinding wheel within the helical groove, the annular zones of stock removal engaged by the land thereafter being cut through by the land, and controlling the speed of rotation of the work-piece so that there is a substantial difference in speed between the surface speed of the land and the surface speed of the workpiece.

10. The method of forming a plurality of similar bodies of revolution which comprises feeding an elongated cylindrical Work-piece along it axis and simultaneously rotating it about such axis so that a point on its surface travels in a helix, progressively'removing stock from the work-piece by presenting thereto an elongated grinding wheel the axis of which converges somewhat toward the path of travel of the work-piece, the grinding Wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, the land pro-gressively engaging the work-piece more deeply at a plurality of annular zones around the axis of the Work-piece as it travels so that after engagement between a plurality of turns of the helical land and the work-piece the latter is engaged between the annular zones and ground by the surface of the grinding wheel within th helical groove, the annular zones of stock removal engaged by the land thereafter being cut through by the land, and controlling the speed of rotation of the work-piece by a regulating Wheel cooperating with the grinding wheel, and driving the regulating wheel so that that there is a substantial difference in speed between the surface speed of the land and the surface speed of the work-piece, the spacing of the regulating wheel and the grindin wheel, and their angle of convergence being such relativ to the initial diameter of the work-piece and the height of the lands on the grinding wheel that severance of the work-piece into separate bodies takes place at a point spaced from the ends of the grinding wheel, and finish grinding the bodies thus separated in the same grinding pass.

11. The method of forming a plurality of similar bodies of revolution Which comprises feeding an elongated cylindrical work-piece along its axis into a centerless grinding machine, the machine being provided with an elongated generally cylindrical grinding wheel having a continuous helical groove on its periphery, adjacent turns of the groove being separated by the turn of a continuous helical land, the grinding machine being further provided with a generall cylindrical regulating Wheel the axis of the regulating wheel being disposed at a substantial skew angle to a plane containing the axis of the grinding wheel and passing through the axis of the regulating wheel substantially at the center of that portion confronting the grinding wheel, the axis of the regulating wheel converging toward the axis of the grinding Wheel in the direction of feed of the work-piece at a substantial angle of approach in such plane, engaging the work-piece between the grinding wheel and the regulating wheel, and rotating the regulating wheel and thus the workpiece as the latter progresses through the machine at a surface speed substantially different from the surface speed of the grinding wheel, whereby the Work-piec is progressively ground at a plurality of annular zones thereabout by the land, is then engaged and ground at zones between the annular zones by the surface of the groove, and is then severed into separate bodies at th annular zones, and such separate bodies are finish ground in the same machine as they travel further past the grinding wheel for a space of the width of a plurality of turns of the groove.

12. Apparatus for shaping an elongated workpiece Which comprises means for feeding such work-piece along its axis and for simultaneously rotating it about such axis, and means for progressively removing stock from the work-piece at a plurality of annular zones spaced along the length of the Work-piece and around the axis thereof as the work-piece travels.

13. Apparatus for forming a plurality of bodies from an elongated work-piece which comprises means for feeding such work-piece along its axis and for simultaneously rotating it about such axis, means for progressively removing stock from the work-piece at a plurality of zones spaced along the length of the work-piece and around the axis thereof as the work-piece travels, and means for progressively severing from the main body of the work-piece at the forward end thereof the bodies formed between such zones of stock removal.

14. Apparatus for shaping an elongated workpiece 'Which comprises means for feeding such work-piece along its axis and for simultaneously rotating it about such axis so that a point on its surface travels in a helix, and grinding means for progressively removing stock from the work-piece at a plurality of annular zones spaced along the length of the work-piece and around the axis thereof as the work-piece travels.

15. Apparatus for forming a plurality of similar bodies from an elongated Work-piece which comprises means for feeding such work-piece along its axis and for simultaneously rotating it about such axis, grinding means for progressively removing stock from the work-piece at a plurality of zones spaced along the length of the work-piece and around the axis thereof as the work-piece travels, and grinding means for progressively severing from the main body of the work-piece at the forward end thereof the bodies formed between such zones of stock removal.

16. Apparatus for forming a plurality of similar bodies from an elongated work-piece which comprises means for feeding such work-piece along its axis and for simultaneously rotating it about such axis, grinding means for progressively removing stock from the work-piece at a plurality of zones spaced along the length of the workpiece and around the axis thereof as the workpiece travels, said grinding means comprising a plurality of narrow rotary grinding instrumentalities rotating about an axis fixed relativ to the path of travel of the work-piece, means for rotating the grinding instrumentalities at a surface speed substantially different from the surface speed of the work-piece, and means for progressively severing from the main body of the work-piece at the forward end thereof the bodies formed between such zones of stock removal, said severing means comprising a narrow rotary grinding instrumentality rotating about the same axis as the above first mentioned grinding instrumentalities.

17. Apparatus for forming a plurality of bodies from an elongated work-piece which comprises an elongated generally cylindrical grinding wheel, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, and means for feeding an elongated work-piece along its axis in a path of travel converging toward the peripheral surface of the land and for simultaneously rotating the workpiece about such axis at a surface speed different from that of the grinding wheel, so that the land progressively removes stock from the Work-piece at a plurality of zones spaced along the length of the work-piece and around the axis thereof.

18. A centerless grinder for shaping an elongated cylindrical work-piece which comprises an elongated generally cylindrical grinding wheel, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a generally cylindrical regulating wheel cooperating with the grinding wheel, means to drive the regulating wheel, means to support the regulating wheel relative to the grinding wheel so that the regulating wheel has substantial skew and approach angles with respect to the grinding wheel, the regulating wheel being spaced from the grinding wheel so that the work-piece may be entered between the wheels at the entering end of the grinding zone and after entering be operatively engaged between the land of the grinding wheel and the regulating wheel.

19. A centerless grinder for formin a plurality of similar bodies from an elongated cylindrical work-piece which comprises an elongated generally cylindrical grinding wheel, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a generally cylindrical regulating wheel cooperating with the grinding wheel, means to drive the regulating wheel, means to support the regulating wheel relative to the grinding wheel so that the regulating wheel has substantial skew and approach angles with respect to the grinding wheel, the regulatin wheel being spaced from the grinding wheel so that the work-piece may be entered between the wheels at the entering end of the grinding zone, after entering will be operatively engaged between the land of the grinding wheel and the regulating wheel, and that the bodies at the forward end of the main body between the zones of stock removal cooperating with the land will be severed from the main body at a point spaced from the ends of the grinding wheel.

20. A centerless grinder for forming a plurality of similar bodies from an elongated cylindrical work-piece which comprises an elongated generally cylindrical grinding wheel, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a generally cylindrical driven regulating wheel cooperating with the grinding wheel, means to drive the regulating wheel, means to support the regulating wheel relative to the grinding wheel so that the regulating wheel has substantial skew and approach angles with respect, to the grinding wheel, and means to adjust the spacing of the regulating wheel from the grinding wheel.

21. A centerless grinder for forming a plurality of similar bodies from an elongated cylindrical work-piece which comprises an elongated generally cylindrical grinding wheel, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a generally cylindrically driven regulating wheel cooperating with the grinding wheel, means to drive the regulatin wheel, supporting means for the regulating wheel, said means disposing the regulating wheel at a substantial angle of approach with respect to the grinding wheel, said regulating wheel supporting means including means for adjusting the angle of skew of the regulating wheel relative to the grinding wheel, and means to adjust the width of the gap of the grinding zone between the grinding and regulating wheels.

22. A centerless grinder for forming a pluralit of similar bodies from an elongated cylindrical work-piece which comprises an elongated generally cylindrical grinding wheel, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a generally cylindrical driven regulating wheel cooperating with the grinding wheel, means to drive the regulating wheel, supporting means for the regulating wheel, said means including means to adjust the angle of approach, means to adjust the skew an le, and means to adjust the spacing of the regulating wheel, all with respect to the grinding wheel.

23. A centerless grinder for forming a plurality of similar bodies from an elongated cylindrical work-piece which comprises an elongated generally cylindrical grinding wheel, means for rotating the grinding wheel about its axis, the grinding Wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a generally cylindrically driven regulating wheel cooperating with the grinding wheel, means to drive the regulating wheel, means to support the regulating wheel relative to the grinding wheel so that the regulating wheel has substantial skew and approach angles with respect to the grinding wheel, means for mounting the regulating wheel supporting means at at least the portion thereof adjacent the regulating wheel for movement toward and away from the grinding wheel, and adjustable stop means cooperating with the regulating Wheel supporting means to determine the grinding gap between the regulating wheel and the grinding wheel.

24. A centerless grinder for formin a plurality of similar bodies from an elongated cylindrical work-piece, which comprises an elongated generally cylindrical grinding wheel, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a generally cylindrical driven regulating wheel cooperating with the grinding wheel, means to drive the regulating wheel, means to support the regulating wheel relative to the grinding wheel so that the regulating wheel has substantial skew and approach angles with respect to the grinding wheel, means for mounting the regulating wheel supporting means at at least the portion thereof adjacent the regulating wheel for movement toward and away from the grinding wheel, adjustable indicating stop means cooperating with the regulating wheel supporting means to determine the grinding gap between the regulating wheel and the grinding wheel, and an adjustable, yieldable, regulating wheel backing up means to thrust the regulating wheel supporting means toward the grinding wheel and into contact with the stop means.

25. A centerless grinder for forming a plurality of similar bodies from an elongated cylindrical work-piece which comprises an elongated generally cylindrical grinding wheel, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a generally cylindrical driven regulating wheel cooperating with the grinding wheel, means to drive the regulating wheel, means to support the regulating wheel relative to the grinding wheel so that the regulating wheel has substantial skew and approach angles with respect to the grinding wheel, the regulating wheel supporting means being mounted for pivoting on an axis, the pivotal axis being spaced from the grinding wheel and the regulating wheel and generally parallel to the axis of the grinding wheel, whereby the regulating wheel supporting means and the wheel carried thereby may be moved toward and away from the grinding wheel, adjustable micrometer stop means cooperating with the regulating wheel supporting means at a point spaced from the pivotal axis of the latter to determine the grinding gap between the regulating wheel and the grinding wheel, and an adjustable, yieldable regulating wheel backing-up means cooperating with the regulating wheel supporting means to urge it about its axis toward the grinding wheel and into contact with the stop means.

26. A centerless grinder for forming a plurality of similar bodies from an elongated cylindrical workpiece which comprises an elongated generally cylindrical grinding wheel, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a generally cylindrical driven regulating wheel cooperating with the grinding wheel, means to drive the regulating wheel, means to support the regulating wheelrelative to the grinding wheel so that the regulating wheel has substantial skew and approach angles with respect to the grinding wheel, means for mounting the regulating wheel supporting means at at least the portion thereof adjacent the regulating wheel for movement toward and away from the grinding wheel, adj ustable stop means cooperating with the regulating wheel supporting means to determine the grinding gap between the regulating wheel and the grinding wheel, the regulating wheel supporting means including a sub-support on which the regulating wheel is rotatably mounted, and means to mount the sub-support for adjustment about an axis generally at a right angle to the axis of the grinding wheel, whereby the angle of skew of the regulating wheel may be selectively adjusted.

27. A centerless grinder for forming a plurality of similar bodies from an elongated cylindrical work-piece which comprises a main machine support, an elongated generally cylindrical grinding wheel rotatably mounted on the support, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a main regulating wheel support pivotally mounted on the main machine support, on an axis generally parallel to and spaced materially from the axis of the grinding wheel, a sub-support for the regulating wheel pivotally mounted on the main regulating wheel support on an axis at right angles to the first named axis, the sub-support having bearing means thereon, a regulating wheel rotatably mounted in the bearing means, means to drive the regulating wheel, means selectively to adjust the sub-support about its axis to the desired angle of skew of the regulating wheel, and means to adjust the angular position of the main regulating wheel support about its pivotal axis to determine the grindin gap between the grinding wheel and the regulating wheel.

28. A centerless grinder for forming a pluralit of similar bodies from an elongated cylindrical work-piece which comprises a main machine support, an elongated generally cylindrical grinding wheel rotatably mounted on the support, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a main regulating wheel support pivotally mounted on the main machine support on an axis generally parallel to and terially from the axis of the grinding wheel, a sub-support for the regulating wheel pivotally mounted on the main regulating Wheel support on an axis at right angles to the first named axis, the thereon, a regulating wheel rotatably mounted in the bearing means, means to drive the regulating wheel, means selectively to adjust the sub-support about its axis to the desired angle of skew of the regulating wheel, means to adjust the angular position of the main regulating wheel support about its pivotal axis to determine the grinding gap between the grinding wheel and the regulating wheel, means to indicate the value of the skew angle, and means to indicate the width of the grinding gap.

29. A centerless grinder for forming a plurality of similar bodies from an elongated cylindrical work-piece which comprises an elongated generally cylindrical grinding wheel, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a generally cylindrical driven regulating wheel cooperating with the grinding wheel, means to drive the regulating wheel, means to support the regulating wheel relative to the grinding wheel so that the regulating wheel has a substantial angle of skew with respect to the grinding wheel, means to adjust the grinding gap between the grinding wheel and the regulating wheel, and means to adjust the angle of approach between the grinding wheel and the regulating wheel, said last named means comprising means to move the regulating wheel supporting means at one end thereof, selectively toward or away from the axis of the grinding wheel.

30. A centerless grinder for forming a plurality of similar bodies from an elongated cylindrical work-piece which comprises a main machine support, an elongated generally cylindrical grinding wheel rotatably mounted on the support, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a regulating wheel support pivotally mounted on the main machine support on an axis generally parallel to and spaced materially from the axis of the grinding wheel, the regulating wheel support having bearing means thereon, a regulating wheel rotatably mounted in the bearing means, means to drive the regulating wheel, means to adjust the angular position of the regulating wheel support about its pivotal axis to determine the grinding gap between the grinding wheel and the regulating wheel, and means to adjust the angle of approach between the grinding wheel and the regulating wheel, said last named means comprising means to move one end of the regulating wheel support at its pivotal axis with respect to the other end of the support and toward or away from the axis of the grinding wheel.

spaced masub-support having bearing means 31. A centerless grinder for forming a plu rality of similar bodies from an elongated cylindrical work-piece which comprises a main machine support, and elongated generally cylindrical grinding wheel rotatably mounted on the support, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helical groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a main regulating wheel support pivotally mounted on the main machine support on an axis generall parallel to and spaced materially from the axis of the grinding wheel, a sub-support for the regulating wheel pivotally mounted on the main regulating wheel support on an axis at right angles to the first named axis, the sub-support having bearing means thereon, a regulating wheel rotatably mounted in the bearing means, means to drive the regulating wheel, means selectively to adjust the subsupport about its axis to the desired angle of skew of the regulating wheel, means to adjust the angular position of the main regulating wheel support about its pivotal axis to determine the grinding gap between the grinding wheel and the regulating wheel, means to indicate the value of the skew angle, means to indicate the width of the grinding gap, and means to adjust the angle of approach between the grinding wheel and the regulating wheel, said last named means comprising means to move one end of the main regulating wheel support at its pivotal axis with respect to the other end of such support and toward or away from the axis of the grinding wheel.

32. A centerless grinder for forming a plurality of similar bodies from an elongated cylindrical work-piece which comprises a main machine support, an elongated generally cylindrical grinding wheel rotatably mounted on the support, means for rotating the grinding wheel about its axis, the grinding wheel having a continuous helica1 groove on its peripheral surface, the adjacent turns of the groove being separated by a helical land, a support for the regulating wheel including a main regulating wheel support pivotally mounted on the main machine support on an axis generally parallel to and spaced materially from the axis of the grinding wheel, a sub-support for the regulating wheel pivotally mounted on the main regulating wheel support on an axis at right angles to the first named axis, the sub-support having bearing means thereon, a regulating wheel rotatably mounted in the bearing means, means to drive the regulating wheel, means selectively to adjust the subsupport about its axis to the desired angle of skew of the regulating wheel, means to adjust the angular position of the main regulating wheel support about its pivotal axis to determine the grinding gap between the grinding wheel and the regulating wheel, means to indicate the value of the skew angle, means to indicate the width of the grinding gap, means to adjust the angle of approach between the grinding wheel and the regulating wheel, said last named means comprising means to move one end of the regulating wheel support at its pivotal axis with respect to the other end of the support and toward or away from the axis of the grinding wheel, adjustable micrometer stop means cooperating with the regulating wheel supporting means at a point spaced from the pivotal axis of the latter to determine the grinding gap between the regulating wheel and the grinding wheel, and an adjustable,

yieldable regulating wheel backing-up means cooperating with the regulating Wheel supporting means to urge it about its axis toward the grinding wheel and into contact with the stop means.

ARTHUR C. MASON.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number Great Britain Mar. 9, 1933 Certificate of Correction Patent No. 2,486,750 November 1, 1949 ARTHUR C. MASON It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 2, line 29, for the Word grinders read grinder; column 8, line 30, for approximately read appropriately; column 14, line 63, and column 15, line 24, for cylindrically read cylindrical;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 7th day of March, A. D. 1950.

THOMAS F. MURPHY,

Assistant Oommz'ssz'oner of Patents.

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