US2428786A - Grinding wheel dresser - Google Patents

Description

R. E. DAHL l GRINDING WHEEL DREssER oct. 14, 1947.`

Filed Npv.` 29, 1945 www? 50' j Patented Oct. 14, 1947 UNITED STATES PATENT OFFICE GRINDING WHEEL DRESSER Robert E. Dahl, Cicero, Ill. Application November 29, 1945, Serial No. 631,709

My invention relates to grinding wheel dressers, `and more particularly to a device adapted to form abrasive wheels, such as grinding wheels, in any desired manner so they may be employed in performing precision grinding or finishing work.

There are abrasive wheel dressers in the prior art, but most of these are complicated and eX- pensive.

One object of my invention is to provide a wheel dresser of simple, sturdy and efficient construction whereby accurate abrasive wheel dressing may be performed in an expeditious, convenient and simple manner.

Another object of my invention is to provide a grinding wheel dresser of such simplicity that it may be manufactured cheaply and thus supply an timportant tool to industry at a reasonable cos A further object of my invention is to provide a novel grinding wheel dresser having stops to limit the amplitude of motion of the tool during the dressing operation.

3 Claims. (Cl. 12S- 11) Other and further objects of my invention will appear from the following description.

In the accompanying drawings, which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

Fig. 1 is a perspective View of a grinding wheel Jdresser showing one embodiment of my invenion.

Fig. 2 is a side elevation of the dresser shown in Fig. 1 with parts in section.

Fig. 3 is a sectional view taken along the line 3 3 of Fig. 2.

Fig. 4 is a sectional view on an enlarged scale taken along the line 4 4 of Fig. 2.

In general, my invention contemplates a suitable base of rigid construction adapted to be positioned adjacent the grinding or abrasive wheel to be dressed. Rotatably mounted on the base I provide a head carrying an arm in which the diamond dressing tool is positioned. It is a feature of my invention that the arm extends beneath the grinding Wheel. This (offers several advantages. First, the wheel is trimmed at the bottom, which is the actual line of contact with the work with which the grinding'wheel is used. Secondly, it is not necessary to move the safety guard from its position over the grinding wheel, thus expediting the operation and guarding the workman from possible injury. Thirdly, the table top on which the base is mounted is in a position closer to the wheel, reducing vibrations and making for accuracy, which is so important in high precision grinding since the position of the nal work can be no more accurate than that of the tool used to perform the work.

The rotatable head .is provided with calibrations to indicate the angle with respect to the vertical .at which the tool is positioned. In order to limit 'the amplitude of motion during the dressing operation, I provide adjustable stops which are a feature of the instant invention. These stops will give the desired amount of arc travel to the diamond.

More particularly, referring now 'to the drawings, a base of any suitable construction is :formed by a bottom plate I carrying a vertical or supporting plate 2 which is secured to the base I by means of machine screws 3. A hub I is secured to the vertical plate 2 by means of machine screws 5 as can readily be seen by reference to Fig. 2. Rotatably carried by the hub I provide a revolving head 6 which may be tted with a head handle 1. A plurality of threaded openings 8 are positioned at spaced points around the head to receive the handle 'I. The lower portion of the head is fitted with a slot into which a diamond holding arm 9 is positioned by means of screw IIB. The screw Iii is annular in form and is internally threaded to receive a set screw I I. A buffer member I2 of soft metal is positioned between the end of set screw II and the hub 4 to avoid marring the hub surface around which the head 6 rotates. The hub 4 is provided with an internally threaded opening I3 adapted to receive the threaded end I4 of a screw I5. The threads II are right handed. The head of the screw I5 .is provided with a threaded portion I6 which threads are left handed in direction. The head of the screw I5 and the threaded portion I4 are joined by a body member having a tapered portion I'I. A knurled clamping disk I8 is threaded on the left handed thread I5. Positioned between the hub 4 and the clamping disk I3 are two stcp plates I9 and 20 provided with stop arms 2I and 22, as can readily be seen by reference to Figs. 1 and 3. The center of stop plate 25J is provided with a beveled opening, the angularity of which from the vertical is less than the inclined surface of the tapered portion I1 of the screw I5. For example, the surface of the opening in stop plate 2i! may have a taper of say fty degrees, while the tapered portion of the screw will be inclined to an angle of sixty degrees from the vertical. In this manner, the

screwing of the screw I5 in a clockwise direction through the use of a screw driver in the slot 23 will hold stop plate 2U in its adjusted position. The stop plate I9 is disposed around a cylindrical portion 24 of the screw I5. The turning Vof the clamping disk I8 in a counter-clockwise direction will clamp both plates I9 and 20 between the clamping disk I8 and the hub 4. Due to the fact that the screw threads I6 extend in an opposite direction from the screw threads I4, the loosening of the clamping diskwill not disturb the setting of the stop plate 29 when it is desired to reset the stops for a different arc of travel.

In operation, if it be desired to dress grinding wheel 25, the base I is positioned adjacent the wheel and secured in any desired manner, as for` example by a magnetic surface plate, clamp, or the like. The parts will then be in 'a position shown in Fig. 1. so as to permit the rotatable head to rotate on the hub 4. The clamping disk I8 is loosenedr and the screw I5 backed 01T to loosen the stop plate 20. r'Ihe stop plate 2U is set so that the arm 22 is in a position giving the desired limit of motion. The screw I5 is then screwed inwardly to hold the plate 2 in its position. V'Ihe stop plate I9 is then adjusted so that its arm 2I is in the desired position of amplitude of motion of the-arm 9. The clamping disk I8 is then rotated in a counter-clockwise direction so as t0 clamp plates I9 and 29 between it and the hub 4. Let us assume that the surface which is to be formed in the grinding wheel isto be convex. In such case, the diamond holder 26 having a diamond point 21 is positioned so that the point 21 is below the axis of the hub 4, and the tool holder 26 is clamped in position by means of screw 28.

The grinding wheel 25 is rotated and the arm i 9 is swung through its arc of motion by means of the handle 'I.

It will be seen that Ihave accomplished the objects of my invention. By means of my stop members I may giveA a grinding wheel a plurality of curvatures, each having a different radius. I have provided a simple, accurate, inexpensive abrasive wheel dressing tool in which the dress- The set screw II is loosened 1. A dresser for abrasive Wheels, including in combination a base, a hub carried by said base,

a. head rotatably carried by said hub, an arm positioned on said head below its axis of rotation, and means for limiting the amplitude of rotation of said head between predetermined limits, said means for limiting the amplitude of rotation of said head comprising a pair of stop members and means for clamping said stop members to said hub. Y

2. A dresser for abrasive wheels, including in l combination a base, a hub carried by said base,

a head rotatably carried by said hub, an arm positioned on said head below its axis of rotation,

and means for limiting the amplitude of rotation of said head between predetermined limits, said means for limiting the amplitude of rotation of said head including a pair of stoppmembers, means for clamping said stop members-to said hub, including a screw having oppositely threaded portions formed thereon, saidfhub being yformed Awith an axially extending internally ing may be performed in an expeditious, coni l tails within the scope of the claims without departing from the spirit of the invention. It is, therefore, to be understood that this invention is not to be limited to the specific `details shown and described.

Having thus described my invention. what I claim is;

threaded re-entrant portion, the end of said 'screw being positioned in said threaded re-entrant portion, and a clamping member threadedly positioned on the other threaded portion oi 3. A dresser for abrasive Wheels, including in combination a base, a hub carried by said base, a head rotatably carried by said hub, an arm positioned on said head below its axis of rotation, and means for limiting the amplitude of rotation `of said head between Vpredetermined limitssaid means for limiting the amplitude ofrotation of said head including aV pair of `stop members, means for clamping said stop members to said v hub, including a screw having oppositely threaded portions formed thereon, said hub being formed with an axially extending internally threaded re-erltrant portion, the end of said screw being positioned in said threadedv re-entrant portion, a clamping member threadedly positioned on the otherthreaded portion of, said screw, said screw being formed with a cylindrical portion and afrusto-conical portion intermediatesaid oppositely threaded portions, one of said stop members being positioned adjacent said frusto-conical portion, and the other of said stop members being positioned ,adjacent said cylindrical portion.

Y ROBERT E. DAHL.

REFERENCES YCITED` The following-references are of record inthe le of this patent:Y f

UNITED STATES PATENTS Number Name Date 2,301,610 ABrady Nov. 10, 1942 2,178,135 Brady Oct. 31, 1939

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