US2401486A - Beveling machine - Google Patents

Description

June 4, 1946. N. B. JONES 2,401,486

' BEVELING MACHINE Filed Dec. 6, 1945 2 Sheets-Sheet 1 Mum 5 L/ZWH June 4, 1946. N. B. JONES BEVELING MACHINE Filed Dec. 6, 1945 2 Sheets-Sheet 2 Patented June 4, 1946 BEVELING MACHINE Norman B. Jones, Toledo, Ohio, assignor' to The Toledo Plate & Window Glass Company, Toledo,

Ohio, a corporation of Ohio Application December 6, 1943, Serial No. 513,079

1 Claim. (Cl. 51 -132) This invention relates to edge beveling machines, and particularly to those for beveling glass plates of circular form.

An object of the invention is the provision of. a machine of this character wherein the work being ground has rotating coaction with the side of a rotary grinding wheel, as distinguished from its periphery, so as to (a) presenta broadsurface for the grinding operation, (b) enable the contact of the work with the wheel to be shifted over the grinding surface to eiiect substantially uniform wear, and (0) cause the grinding action to serve as the dressing means for the wheel, thus prolonging the effective life of the wheel andenhancing the practicability and commercial value of the machine.

Another important object of the invention, resulting from grinding contact of the work to be beveled with the side of the grinding wheel, is that it enables the radial width of a bevel and the speed of grinding to be varied by shifting the point of contact of the work with the wheel transverse to a radial line of the wheel which intersects the axis of rotation of the work.

A further object of the invention is the provision in a grinding machine of the class described and wherein a marginal side edge portion of a rotary work piece has grinding coaction with a side of a rotary grinding wheel, of mean for adjusting the face plane of one of said-rotating members to that of the other to eiiect an angular engagement of the members to suit the desired inclination of the bevel being ground.

A further object of the invention is the provision in a grinding machine of the class described, and wherein a marginal side edge portion of a rotary work plate has grinding coaction with a side of a rotary grinding wheel, of means for relatively positioning the Work plate and grinding wheel whereby they are disposed in diverging planes of rotation suitable for the angle of the bevel to the work plate edge with the wheel intersecting a registering radius of the wheel at an angle which is other than normal thereto.

Further 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 plan view of the machine embodying one form of the invention and in which two work carrying units are shown, with the work pieces carried thereby of different sizes and in beveling engagement with different side portions of a single grinding wheel; Fig. 2 is a side elevation of the machine, one work carrying unit only being shown; Fig. 3 is a vertical section on the line 33 in Fig. l, with the stone contacting area of each work piece more or less diagrammatically shown; Fig. 4 is a similar view illustrating the relatively small point of beveling contact of the work piece; with the stone when such point falls on a line which substantially intersects the axes of rotation of both work piece and stone; Fig. 5 is a fragmentary View of a grinding wheel and coacting work piece in the. relative positions of engagement shown in Fig. 4 and with the work piece in initial sharp edge coaction with the wheel; Fig. 6 is an enlarged fragmentary view of Fig. 3 illustrating the line of contact of the Work piece with the wheel with the bevel finished; and Fig. '7 is a fragmentary section on the line 1-1 n l 7 Referring to theform of the invention shown in Figs. 1 to 7 of the-drawings, l designates a base frame or standard at the top'of which, in suitable bearings 2, is mounted the shaft 3 carrying at one end the grinding wheel 4. This-shaft, in the pres,- ent instance, is horizontally disposed and has driven belt and pulley connection 5 with a motor 6 mounted in thebase portion of the frame I. The wheel 4 is clamped to a fixed collar '1 on the shaft 3 by a nut 8 at its outer side, thus permitting easy removal and replacement of the wheel. The working side ofthe Wheel 4, the outer side in the present instance, is preferably but not necessarily formed on a bevel 4 or of conical form, so that the wheel gradually diminishes in thickness from an area near its center to its outer edge.

On a frame 10,- at the grinding wheel side of the machine, are mounted, in the present instance, two work-piece carrying'units A and B positioned for the respective work-pieces C and Dcarried thereby to have edge beveling engagement with the tapered side of the wheel 4 at opposite sides of itsaxis. 7

Each unit A, B, includes a base plate ii that is clamped to the top of the frame In for various horizontaladjusting movements by bolts I3 extending through slots M in the base plate and crossingslots l5 in theframe top. A shaft It is mounted for rotary and axial movements in bearings ll rising from the base plate l2 and is disposed for its axis to intersect the plane of rotation of the grinding wheel 4. This shaft-is driven by. a'motor l8 through a suitable change speed connection comprising,- inthe present instance, a belt and variable V-pulley connection 19, between the motor shaft and a lower shaft (not shown), and a belt and pulley connection 20, be-

tween such lower shaft and the shaft I6. The motor is mounted on a bracket 2| projecting from and movable with the base plate [2.

The work C or D, as the case may be, may and usually does constitute a glass plate of circular form and is concentrically clamped to a work holding plate 22 on the shaft l6 by vacuum action in order to leave the edge of 'the plate free and prevent the necessity of providing holes in the plate for attaching a securing means thereto. The shaft has a longitudinal passageway 23 therethrough opening at one end at the workpiece clamping side of the plate 22 and at its other end to a vacuum source (not shown) through a flexible tube 24, thus enabling a vacuum to be created at the plate end of the shaft to hold a work plate thereto. The work plate has a sealing fit against the holding plate to prevent relief of the vacuum, as well understood in the art.

The work plate is positioned for its edge to lap a side of the grinding wheel 4, the tapered side in the present instance, and its axis of rotation is horizontally adjusted relative to that of the wheel, as may be desired,'by a horizontal adjustment of the base plate l2 on the frame Id. In order to move the work plate into and out of engagement with the grinding wheel, the shaft 16 is axially shiftable in any suitable manner. This is accomplished, in the present instance, by shifting the shaft axially in its bearing and effecting such shifting by movements of a hand lever 26, one arm of which has forked connection with a collar 21 on the shaft. v

In order to obtain the most efficient, speedy and economical beveling action it is desirable to so dispose the axis of rotation of the work plate with respect to that of the grinding wheel that the work plate edge engages a' side face of the wheel at a point which is offset laterally from a line an (Figs. 3 and 4) which intersects the axes of the wheel and work plate, or substantially so, with the plane of rotation of one disposed in intersecting or tilted relation to that of the other, so that the lapping portions of said faces are spaced at said line. This relative positioning of the faces is accomplished, in the present instance, by tilting the shaft [6 in a vertical plane by raising the outer end of the base plate l2 of the work carrying unit by the manipulation of a screw 30 which threads up through the top of the frame I0, as shown in Fig. 2. The clamping bolts l3 must, of course, be first loosened. r

If the area of contact of the wheel and work is substantially coincident with the line a, as shown at b (Fig. 4), the area of contact is small. the wearing or disintegrating action on the stone is severe and the grinding of the work-bevel is comparatively slow due to the circular line of the work edge crossing the radial line a at an angle substantially normal thereto; With this relationship the sharp edge c (Fig. 5) of the work plate not only cuts into the stone surface, thus quickly grooving or rendering the stone surface irregular,

but the length of contact of the work edge with the stone can never be greater than the width of side of the line a, the edge line 0 of the work, at"

its point of contact with the stone, is disposed obliquely to an intersecting radial line, such as d (Fig. 3) of the stone, so that the area of beveling action, compared with that shown in Fig. 4, is not only prolonged circumferentially of the work, but also radially of the stone surface, as shown at 6 (Figs. 3, 6 and '7). This materially lessens the grooving of the stone face during the grinding action and speeds u the grindingoperation. It is apparent that the more remote the point of grinding is from the line a the more nearly will the line of circumferential contact of the work edge with the stone register lengthwise with an intersecting radial line of the stone.

It will be noted that in the embodiment of the invention illustrated in Figs. 1 to 4, the axes of rotation of the work-piece and grinding wheel are relatively divergent in two planes, one plane, for the purpose of identification, being horizontal and common to both axes, and the other plane being vertical or in intersecting relation to the first plane. The divergence of the axes in the socalled horizontal or common plane, or toward each other, while preferable in practice, is not necessary, but the other relative positioning of the axes whereby the work-piece and wheel have lapping coaction in divergent relation at one side of a line intersecting the two axes is important in this embodiment of the invention and is the particular feature that produces the improved result desired.

If the machine is provided with two workcarrying units, as illustrated, they should be positioned so that the work-pieces carried thereby may engage the same grindin wheel at opposite sides or its axis and preferably at pointson' the face of the wheel which are differently-spaced from its axis, thus causing a more even wear of the wheel surface. In practice, the grinding wheel is driven at a high speed and the work-pieces are driven at relatively low speeds. It is found that a speed of approximately 225 R. P. M. of the wheel and 28 R. P. M. of the work-piece produces good results. This speed may, of course, be varied to suit the particular grinding conditions, and for this purpose either or both of the stone and work plate drives ma include a variable drive feature.

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

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

In a plate edge beveling machine, twotransversely spaced shafts, means for driving eachof said shafts, a frusto-conical abradin'g wheelcarried by one shaft and the other shaft having means adapted to carry a workpiece to.rotate therewith with its face plane normal to it axis of rotation, means forsupporting one of said shafts including a frame, abase plate on said frame, and bearing means on said base plate receiving said last mentioned one. of said'shafts, means for shifting said last mentioned oneiof. said shafts axially of said bearing means, said means for driving said'last mentioned.- one of said shafts comprising 'a motor mountedon said base. plate, and adjustable means fixedly securing saidbase plate to said frame in position to maintain the axes of rotation of said shafts relatively divergent in both horizontal and vertical directions.

r g NORMAN, B.,JONES.1

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