US2376959A - Abrading wheel dressing means - Google Patents

Description

May 29, 1945. A. G. CHRISTEL ET AL 2,376,959

ABRADING WHEEL DRESSING MEANS Filed April 14 1944 2 Sheets-Sheet l III III II. ll..| 4 1 l INVENTORS G. Christel and KO?! Fuchs l i hon May 29, 1945- A. G. CHRISTEL ET' AL 2,376,959

ABRADING WHEEL DRESSING MEANS Filed A ril 14, 1944 2 Sheets-Sheet 2 H A rh GCh' 7/ 2 QQd fi i'rr AQTW Patented May 29, 1945 I "masonic. WHEEL nanssmo Means Anthony G.- Christel and Karl Fuchs-T Rochester, N. Y.

Application April 14, 1944, Serial No. 531,072 -(Cl. 125-41) 2 Claims.

This invention relates to themachine tool art and particularly to means for the precision dressing of abrading wheels.

According to the present invention means are provided which permit the dressing of contours comprising angles and radii, either by them selves or in any desired combination. As a re sult, forms or contours composed entirely of radii and straight lines, whether the latter be parallel to the axis of the wheel being dressed, or obliquely extending, may be fully dressed in a highly precise, simple and continuous manner.

Basically, the present arrangement of elements is novel in that it superimposes radius dressing elements on angle {dressing instrumentalities, whereby a straight line angle dressing operation may be interrupted at any point, without disturbing the precision setting, to merge the line of angle dressing into any desiredradius.

The elements of the device ofthe present in.- vention are so arranged that angle settings may be effected by the sine bar method, whereby pre cision gage blocks may be employed with refer ence to suitable sine bar tables, to set the tool for angle dressing of the highest degree of accuracy. The radius setting arrangement of the tool herein disclosed is likewise such that precision gage blocks may be employed'in radius setting, although means'are also provided for accurate setting by means of micrometer calipers, when desired. Q

The various elements of the presentinvention are so arranged as to permit manufacture on an economical and practical basis, despite the fact that the critical surfaces and dimensions along a line parallel tothe axis of rotation of the wheel to be dressed;

Fig.- 2 is an elevational view at right angles.

to Fig. I, viewed perpendicular to the axis of the wheel to be dressed and with the device at ranged to dress an angular periphery; and

Fig. 3 is a cross section on Fig. 1.

Throughout the several figures of the drawings like characters of references denote like parts and the numeral l0 designates a base plate having a precision-ground lower surface. For convenience, the tool will be described with reference to use with a surface grinder having a magnetic chuck, whereby the precision lower surface, of the tool base plate I!) may be placed directly on the magnetic chuck table for setting the angles andradil to be dressed.

The base plate It! hasfa pair of upwardly extending lugs l'l atone endthereof, the lugs being at opposite sides of the base plate In to serve as hinging lugs for a further support element II, the latter "comprising a support for the dressing means proper and being settable in highly precise angular relationship with respect to the base plate In, in a manner which will presently appear. f ,7

The hinged edge of support element I2 is provided with a. right-angle groove l3 and a hinge pin 14 is held intimately seated in groove I3 andagainst both surfaces thereof by screws the line .III -III of l5, which extend obliquely through the pin it of the device may readily be madeto the highest degree of accuracy attainable in the toolmaking art. to both the .manufacture and convenient and practical use of the tool of the present invention will occur to those skilled in the toolmaking and machine tool art from a study or the following detailed description, considered in con- Junction with the accompanying drawing.

While a full and complete embodiment of the principles of our invention is set forth herein by way of example, it is to be understood that the form illustrated and described is merely by way of example. The spirit and scope of our invention is not to be considered limited, excepting as defined in the appended claims.

In the drawings: v

Fig. 1 is an elevational view of a preferred form of the tool of the present invention viewed Other objects and advantages, pertaining and into the support element l2. The lower surface of support element I! has a second groove l6 spaced from the groove l3, parallel thereto,

and preferably adjacent the opposite edge of support element 12. The groove l6 has a pair of right angle surfaces corresponding to those of, groove is and an identical pin I1 is held thereagainst by oblique screws l8.

Theioregoing, arrangement provides a convenient and practical means of insuring highly jprecise horizontal disposition of support element [2 when in the position illustrated in Fig. 3-, the lower surfaces'of hinge pins l4 and pin I"! being tangent to a common horizontalline lying in the plan orthe flat upper'surface of base plate l0. g f The support element 12' may be held firmly in any angular position of adjustment with respect to base In by virtue of the particular construction of hinge lugs II. The openings in lugs H which receive the ends of hinge pin l4 each havelateral slots 20 extending therefrom and screws 2| pass ire-ely through the lug portions above the slots and thread into the lug portions below the slots, whereby the hinge assembly may be securely locked or readily freed for adjustment by merely tightening or loosening screws 2|, as the case may be. i

The upper surface of base I9 is precision formed and the right hand surfaces of the grooves l3 and I6 are spaced at a precise distance from each other. Because of this the support element [2 may be set'at any desired angle about hinge pin l4 by loosening screws'2l and, with-appropriate reference to ment l2 so that a predetermined precise dimensine tables, setting the support elesion exists between the upper surface ofzbase Ill) and the lower surface of pin I'I. The rnanner in which these elements are arranged permits ready use of the highly accurate gage block method of setting the device. son blocks is preferred, any other precision measuring means may be employed, such as 'ah'eight' gage, micrometer calipers, or the like.

The upper surface ofsupport lement I2 is formed to support ablock for accurately guided lineal movement thereon. .To this .end a pair of undercut guide bars 26 are secured to opposite sides of the upper surface of Support element l2 and engage-complementary groove formations in block 25 to guide the same for movement in a direction at right angles to the axisof pivot pinl4.

It is desired that lineal -movement of block 25 along support element. l2 be under convenient and certain external manual control and for this reason rack; teeth 28 areformed inthe upper surface of support element 12 as appears from Fig. 3. A sector gear 29is mounted on a control shaft 30 journaled in opposite sidewalls of block 25, the latter having an open central. portiongas appears best. at 3| in Fig.1; Externally of the block 25 the .control shaft 30 is extended and has a manipulating knob 32. The sector gear 29 meshes with rack teeth .28 vto provide accurate guided movement of block 25 along the support element l2through manual control and manipulation of knob 32.

It will .be noted that the ends of the seriesnof rack teeth and the arcuate extent of the sector gear 29 are so proportioned thata positive limit of movement in either direction is provided by engagement of end teeth of the sector gear 29 with untoothed portions of thesupport. element l2. In Fig. 2 the limits-of movement of the block 25 are illustratedin dot and dash lines, the full line position of Fig. 2 being a mid-position.

At its upper portion the block 25 has a bearing which receives a shaft 36 journaled on an axis parallel to the axis of control shaft 30 and to the axis of hinge pin l4. Shaft 36 has a manipulating knob 38 secured tooneextending end thereof, at the same side as knob .32, and at its other side has an oifset bracket 39 which has at its outer end a diamond or other abrading wheel dressing element 49 set in a holder 4| in conventional manner.

The holder 4 l-has a cylindrical shank 42 which fits in a sleeve.43.. The sleeve 43 has a collar 44 which seats inthe bracket 39 and the sleeve 43 preferably has a press fit in the opening formed in bracket 39 to receive it. The shank 42 is hollow, as at 45,.anda-compression coilspring 46 normally urges holder 4| outwardlyof sleeve 43 (upwardly as viewed in Fig. 1). A setscrewfl extends through the end of the bracket 39 and through sleeve 43 and engagesagainst the shank "420i holder 4| to retain it'inadjustedposition.

It will be seen from the foregoing that the dressing element, may be placed at various distances from an extension of the axis of rota,- tion of shaft 35 and that such distance will determine the radius through which the dressing face of the dressing element will travel upon manual rotation of shaft '36 through knob 38.

Further it will be seen that for dressing convex radii on an abrading wheel the dressingelement 49 will be set/the desired distance below the axis of shaft 36, as viewed in Fig. 1, whereas for dressing concave radii the dressing element will be set above such axis.

The bottom of sleeve 43 is adjusted to a precise,

exact and known distance from the axis of bearing 35 and shaft 35, so that the dressing element may be set the desired distance from such axis Whilerthe'use-of'Johans by setting a micrometer caliper and placing it over the bottom of sleeve 43 and the dressing element 49. The set-screw 41 is then merely loosened, if it is not already so, and. spring 46 will urge the dressing element 40 and the bottom of sleeve 43 into engagement with the opposite jaws of the calipers. Further, the upper surface of block 25 is formed fiat and true and in accurate parallelism with the axis of shaft 36 and a given precise and known distance therefrom. The dressing element4ll may thus also be set for radius dressing by inverting the entire assembly and placing it on a surface plate or on the magnetic chuck table of a grinding machine. Gageblocks may thus be employed between the surface plate and the dressing element as in the setting of angles. I i

To enhance and facilitate accuracy of control, means are provided for maintaining the radius dressing shaft 36 and dressing element 40 in'rigid- 1y fixed relationwith respect to block'25 during angle dressing operations. Itis desired that the V dressing element holder 4I'be perpendicular to thev support element l2 during such operations and accordingly the block 25 is perforated at oppositesides-ofbracket 39 to receive stop pins 50. The pins'are readily'removable to perform radiu dressing operations and one of the pins may remain in position to insure accurate tangency between a radius dressing component and an angledressing component. Y r

The radius dressing bracket 39 may be arrested and locked inany desired position with respect to its supporting block 25 by a hand screw} 53 which threads into block 25 and whose end engages against shaft 36, Likewise, the quadrant and rack 29 and 28 may Ice-similarly lockedin any desired relative positionby a hand screw 54 v which threads into block 25 andis engageable against shaft 30... I

A groove 55 is formed in the upper surface of base l0,;as appears in Fig. 1, and this groove is of a highly precise and known'depth say one hundred one thousandths,- for convenience. This permits the use of gage-blocks of material thick.-

.ness even though the distance to be gaged. be

tween the bottom of pin l1 and the upper surface of base Ill is extremely minute. I

A medial angular .groove 56 is also formed in the undersurfaceof the support element I2 to permit the stacking of gage blocks under pin 1-! when the angle between thee-base plate It and support element l2 approaches without in.- terference 'fromthe lower surface ofelement. l2 adjacent the groove IS. The grooves-.55. and- 56 are preferably oifset horizontally in' the plane of Fig. 1, so that. the presence of groove 55 does not interfere in any Way when large angles are bein aged.

What is claimed is: 1. Grinding wheel dressing means comprising a base having a flat relatively unobstructed precision formed upper surface portion, a, member pivotally connected thereto'for adjusting movement about a, horizontal axis and having a portion offset from said axis disposed above said surface portion, a. precision gage pin rigidly associated with said offset portion in predetermined precise relationship with respect thereto, a lower portion of said pin being exposed whereby angularity of said member with respect to said base by pivotal movement therebetween may be accurately determined by gaging between the upper surface portion of the base and said gage cision' formed upper surface portion, a member pivotally connected thereto for adjusting movement about a horizontal axis and having a .portion offset from said axis disposed above said surface portion, a precision gage pin rigidly associated with said ofiset portion in predetermined precise relationship with respect thereto, a lower portion of said pin being exposed whereby an ,gularity of said member with respect to said base by pivotal movement therebet'ween may be accurately determined by gaging between the upper surface portion of the base and said gage pin, a support member mounted for lineal guided movement along said member at right angles to the axis of said pivotal connection, a gear element mounted on one of said members for free rotation on an axis parallel to said horizontal axis and a meshing rack fixed to the other of said members, manual means for rotating said gear element. to control lineal movement of said support member, a dressing element and means mounting the same for rotation relative to said support about an axis likewise parallel to said horizontal axis, and means for adjusting said dressing element relative to said mounting means in a direction transverse to its'axis of rotation.

' ANTHONY'G. CHRISTEL.

KARL FUCHS.

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