US3451385A - Grinding machine - Google Patents

Description

June 24, 969 P. c. DOOLEY, JR

GRINDING MACHINE Sheet Filed April 24, 1967 FIG.

F lG.2

INVENTOR. PETER C. DOOLE BY )f June 24, 1969 P. c. DOOLEY, JR 3,451,385

GRINDING MACHINE Filed April 24, 1967 Sheet 2 of 2 I NV E NTOR.

FIG 4 PETER c. DOOLEY,JR.

United States Patent 3,451,385 GRINDING MACHINE Peter C. Dooley, Jr., Lewiston, N.Y., assignor to The Carborundum Company, Niagara Falls, N.Y., a corporation of Delaware Filed Apr. 24, 1967, Ser. No. 633,279 Int. Cl. B24b 53/00, 55/00 U.S. Cl. 125-11 Claims ABSTRACT OF THE DISCLOSURE This invention relates to grinding machines, and more particularly to devices for use on grinding machines for accurately conditioning the active surface of an abrasive wheel.

In grinding machines incorporating grinding wheels, it is necessary to reshape or resurface the peripheral surface or working face of the wheel frequently in order to obtain a true peripheral profile on such face for efficiently and accurately removing stock from work. This resurfacing technique is commonly referred to as a dressing and truing operation. Quite often, this is effected by a hand tool which requires brute strength to hold the tool against rapidly rotating grinding wheel. Obviously, the possibility of obtaining a true and accurate profile is very remote.

It has also been known to employ truing devices as an integral part of the grinding machine. Although these devices have served the purposes for which they are designed, they have not been entirely satisfactory because of their awkward mounting relationships with respect to the grinding wheel. Very often, the removal of obstrucing equipment is necessitated in servicing the truing device. Also, the truing device must be completely removed when changing the grinding wheel. Sometimes these devices are located adjacent the exposed working area of the wheel subjecting the operator to flying grit and debris.

The general purpose of the present invention is to obviate the above disadvantages by providing an improved dressing and truing mechanism and mounting therefor.

Accordingly, it is an object of the present invention to provide a new and improved dressing and truing mechanism for a grinding wheel.

It is another object of the present invention to provide a new and improved dressing and truing mechanism for a grinding wheel having all operative or working parts encased in the wheel guard and remote from the exposed working area of the grinding wheel.

It is a further object of the present invention to provide a new and improved dressing and truing mechanism mounted on a pivotable wheel guard door.

These and other objects of the invention will become more apparent upon consideration of the following detailed description thereof when taken in conjunction with the following drawings, in which:

FIG. 1 is a rear elevational view of a grinding machine in which a preferred illustrative embodiment of the invention is incorporated;

FIG. 2 is a side elevational view of the grinding machine illustrated in FIG. 1;

FIG. 3 is an enlarged side elevational view, partially in section, illustrating the truing and dressing mechanism constructed in accordance with the principles of this invention;

FIG. 4 is a sectional elevational view taken on the plane of line 4-4 of FIG. 3.

Referring now to the drawings and particularly FIGS. 1 and 2, it will be observed that a preferred embodiment of this invention is incorporated in a grinding machine, generally designated 10, having a rear frame 12 suitably mounted on a base 14.

A grinding wheel 16 is suitably rigidly secured to a rotatable spindle 18 for rotation therewith and is partially enclosed by a wheel casing or guard 20, mounted on base 14, for confining debris resulting from the cutting operation. Wheel guard 20* is provided with an arcuate cutaway portion 22 for exposing the active surface of the grinding wheel to work. This cutaway portion defines the working area of the wheel.

One side wall of the wheel guard 20 comprises a door 24 hingedly connected to the rear wall 26 of the guard, as by means of suitable pivotable connections 28, to provide access to the grinding wheel 16. The door 24 may be releasably secured to the guard 20 by any suitable clamping means 30'.

'Rigidly secured onto frame 12 is a motor 32 having an output shaft 34 to which is rigidly secured a drive pulley 36. An endless drive belt 38 is trained about drive pulley 36 and a driven pulley 40* for rotating spindle 18 and thereby grinding wheel 16.

A sector plate 46 is pivotably connected to the exterior side of door 24 about a horizontally oriented pivot 48. Means are provided for swinging plate 46 upwardly or downwardly about pivot 48, said means comprising an elongated rod 50 having a rod end bearing 52 at one end thereof, pivotably connected to plate 46 by means of a suitable bolt 54, the other end of said rod having an external threaded portion 56 threadably received in ad elongated internally threaded rod member 58. Member 58 extends through an opening in lug 60 and is provided with a hand wheel 62 at the end remote from rod 50. A pair of abutement collars '64 and 66, having outside diameters larger than the opening in lug 60, are rigidly secured on rod member 5 8 on opposite sides of lug 60 to prevent axial movement of rod member v58. Thus, it will be seen that rotating hand wheel 62 will cause rod member 58 to rotate and since axial movement thereof is restrained, rod 50 will move axially relative to member 58 effecting pivotable movement of plate 46.

Elongated arcuately curved Teflon strips 68 are secured onto the exterior side of door 24 and serve as bearing surfaces to minimize friction as the plate 46 moves relative to door 24. Spring loaded guide clips 69 are secured onto door 24 to prevent plate 46 from moving outwardly relative to the door 24.

With reference to FIG. 4, it will be seen that a screw jack 70 is provided for effecting movement of the dressing and truing tool 72 in directions parallel to the axis of the grinding wheel 16. \Although a star type dresser is preferred as shown in FIG. 4, it should be realized that the principles of this invention envisage the use of any suitable type of a wheel dresser.

Dressing and truing tool 72 is suitably mounted for free rotation on a ball bearing sleeve (not. shown) carried by bolt 74 located on a toolholder 76 threadedly secured onto a threaded extension '78 projecting from the end of screw jack 70 and abuttingly engageable with a flanged slide, generally designated 80. Slide 80 comprises an inner body member 79 encasing the end portion of screw jack 70 and an outer tubular member 81 telescopically surrounding a sleeve -82 suitably secured to plate 46.

Movement of slide member -80 and thereby wheel dresser 72 is effected by worm 86 and worm wheel 88 cooperating with screw jack 70. The worm wheel 88 is rotatably mounted in a saddle 90 secured in a casing 92 and the screw jack 70 extends through a screw threaded aperture 94 in the center of the worm wheel 88. Since saddle '90 prevents axial movement of worm wheel 88, rotation of said worm wheel effects axial movement of screw jack 70. An extension 96 of casing 92 is provided for accommodating the free end of jack 70 and permitting axial movement thereof. It will be seen that extension 96, housing 92, sleeve 82 and slide 80 serve as an enclosure for screw jack 70 and protect the same from dust and debris. A circular, radially inwardly extending portion 98 of extension 96 is provided with a solt 100 for positioning a key 102 therein and a longitudinal slot 103 is provided in screw jack 70 for accommodating said key in order to prevent rotation of jack 70 while allowing longitudinal movement thereof.

With reference to FIG. 3, it will be seen that worm 86 is drivably connected to a hand wheel 104 by means of an elongated rod 106 through a universal connection 108. An areuate upwardly extending slot 110 is provided in door 24 to accommodate the swinging movement of the screw jack housing.

The general mode of operation of the improved dressing and truing mechanism is as follows:

When it is desired to dress and retrue the grinding wheel 16, the operator manipulates hand wheel 62 to swing sector plate 46 upwardly for bringing the attached dressing and truing tool 72 into contact with the active or peripheral surface of the wheel. Referring to FIG. 2, it will be seen that the plate 46 is shown in full lines in use with a new wheel and the phatom lines indicate a position in which the plate has been swung upwardly with the dressing and truing tool in contact with the grinding wheel which has become somewhat worn. The pivotally mounted plate 46 has sufficient travel to enable the dressing and truing tool 72 to follow the grinding wheel throughout its life. Operation of the hand wheel 104 traverses the dressing and truing tool 72 back and forth across the face of the wheel as the wheel is rotating to accurately dress the active face of the wheel. If desired, the hand wheel control 104 can be replaced by a small gear head motor with limit switches to effect continuous transverse reciprocating movement of the tool across the peripheral surface of the grinding wheel upon command until said surface has been properly dressed and the wheel is once more running true.

As a result of the present invention, an improved dressing and truing device is provided for quickly and easily conditioning a grinding wheel face and establishing good running truth. By mounting the dressing and truing device on the wheel guard door, the operative or working parts of the mechanism can be readily exposed and made accessible by merely swinging the wheel guard door open. Moreover, the dressing and truing mechanism does not interfere with grinding wheel replacement.

Another advantage residing in the apparatus of this invention is that the dressing and truing mechanism is mounted remotely from the working area within the wheel guard, thus preventing debris from contaminating the exposed or working area of the wheel. Although the dressing and truing mechanism never interferes with the normal operation of the grinding wheel, it is positioned so as to be available on command to retrue the grinding wheel.

A preferred embodiment of this invention having been described and illustrated, it is to realized that modifications thereof may be made without departing from the broad spirit and scope of this invention as defined in the appended claims.

I claim:

1. Apparatus for dressing and truing a grinding wheel comprising: a plate; an elongated screw; means for mounting said screw on said plate; means for moving said screw axially in either direction; a sleeve fixed to said plate and partially surrounding said screw; a slide telescopically mounted on said sleeve and having a portion connected to one end of said screw for movement therewith; a tool holder mounted on said slide; and means for mounting a dressing and truing tool on said tool holder.

2. Apparatus for dressing and truing a grinding wheel as defined in claim 1 wherein said dressing and truing tool is mounted for rotational movement on said tool holder.

3. Apparatus for dressing and truing a grinding wheel as defined in claim 2 in which said means for moving said screw comprises a worm wheel operatively connected to said screw and a worm threadably engageable with said worm wheel.

4. Apparatus for dressing and truing a grinding wheel as defined in claim 3 including means for rotating said worm.

5. Apparatus for dressing and truing a grinding wheel as defined in claim 4 including means disposed adjacent the other end of said screw for preventing rotation of said screw while permitting axial movement thereof.

6. A grinding machine comprising: a base; a frame supported on said base; a rotatable grinding wheel; means for mounting said grinding wheel on said frame; a wheel guard mounted on said frame; said wheel guard partially enclosing said wheel and having a door; a plate pivotally mounted on said door; means for swinging said plate about a pivotal axis; an elongated screw; means for mounting said screw on said plate; means for moving said screw axially in either direction; a sleeve fixed to said plate and partially surrounding said screw; a slide telescopically mounted on said sleeve and having a portion connected to one end of said screw for movement therewith; a tool holder mounted on said slide; and means for mounting a dressing and truing tool on said holder.

7. A grinding machine as defined in claim 6 wherein said dressing and truing tool is mounted for rotational movement on said tool holder.

8. A grinding machine as defined in claim 7 in which said means for moving said screw comprises a worm wheel operatively connected to said screw and a worm threadably engageable with said worm wheel.

9. A grinding machine as defined in claim 8 including means for rotating said worm.

10. A grinding machine as defined in claim 9 including means disposed adjacent the other end of said screw for preventing rotation of said screw while premitting axial movement thereof.

References Cited UNITED STATES PATENTS 957,689 5/1910 King 11.2 981,810 l/l91l Sterling 1251l.2 1,436,087 11/1922 Furber i 12511.2

JAMES L. JONES, JR., Primary Examiner.

US. Cl. X.R.

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