US2926461A - Auxiliary compound angle grinder for surface grinding machines - Google Patents

Description

March 1960 G. BANKQ 2,926,461

AUXILIARY COMPOUND ANGLE GRINDER FOR SURFACE GRINDING MACHINES Filed Sept. 8, 19.58 4 Sheets-Sheet l INVE R. 650265 o ATTOEN March 1, 1960 G. BANKO 2,926,461

AUXILIARY COMPOUND ANGLE GRINDER FOR SURFACE GRINDING MACHINES Filed Sept. 8, 1958 4 Sheets-Sheet 2 FLE-EJ IN VENTOR.

I 660265 BAN/ 0 G. BANKO March 1, 1960 AUXILIARY COMPOUND ANGLE GRINDER FOR SURFACE GRINDING MACHINES Filed Sept. 8. 1958 4 Sheets-Sheet 3 March 1, 1960 G. BANKO 2,926,461

AUXILIARY COMPOUND ANGLE GRINDER FOR SURFACE GRINDING MACHINES Filed Sept. 8. 1958 FIE E 4 Sheets-Sheet 4 ||||H NHL.

Fis 7 INVENTOR. Geo/26.:- BAN/ 0 ATTOEA/EI.

v This invention relates to grinding machines andparticularly toa compound angle grinding attachment for surface grinding machines.

This invention relates'to an improvement in the "device described and claimed in my U.S. Patent No. 2,821,815,

issued February 4, 1958, and entitled, Auxiliary Compound Angle Grinder For Surface Grinding Machines. The primary object of this invention is to, provide .means for substantially increasing the length of the grinding stroke of said attachment without change in the width of the slide.

Another object is to provide "a structure of the type stated, for mounting on a conventional surface grinder spindle housing, whose sub-table reciprocating driveshaft remains stationary at all times with reference to'the surface grinder spindle.

A further object is to .provide a resilient belt drive between the surface grinder spindle and the auxiliary reciprocating spindle. I

Still another object is to provide micro-adjustabilit y for the length of stroke of the reciprocating sub table spindle.

These and other objects of the invention will'become apparent from a reading of the following specification and claims, together with the accompanying drawings, wherein:

Figure l is a perspective view'of the auxiliary compound angle grinder that is the subjectof this invention, showing it mounted on the spindle of a conventional surface grinder;

Figure 2 is a longitudinal sectional view of theattachment showing the relation of the various interconnected rotating and reciprocating elements;

Figure 3 is a vertical sectional view taken along the the line and in the direction 'of'the'arrows 33- ofFigure 2;

Figure 4 is a top plan view of the device;

Figure 5 is a' horizontal sectional View taken along the line and in the direction'of the arrow 5-5 of Figure'2;

Figure 6 is a vertical sectional viewtaken along the the line and in the direction of the arrows 66 of Figure 2; and

Figure 7 is a perspective view of the unmounted first crank arm, showing the dovetail ,slot thereof.

Referring more particularly to the drawings there is seen in Figure 1 the auxiliary compound angle grinder that is the subject of this invention,broadly indicated by reference numeral 10, as it appears mounted on the spindle housing 67 of a conventionalsurface grinder 30, outlined in broken-lines. r

The surface grinder, broadly indicated by reference numeral 3%) is of the usual type having a reciprocating table 32 upon which is supported avise 33 in which the work piece 34 is held. An upright post or column 31 supports the usual motor driven grinding wheel spindle 29 in its housing 67.

The auxiliary compound angle grinder 1i is'comp'osed Fatented .Mar 1., .1966

a .of -threemajor parts, namely, .a bracket 11,;a..stat'ionary table 15 and a reciprocating sub-table 49. The bracket 11 .is mounteddirectly overthe spindle housing 67 of the surface ,grinder v30 .by means of a split collar 12 which .isc'ompressed around thespindle housing .67 by means of abolt 14, as is seen most clearly in Figures 2 and 4. v A pointer 35 .is mountedon the post '31.at thecenter line of the spindle 29. This serves as a vertical pointer ..for the angle scale 13 which extends upwardly of the bracket collar 12 for a purposeto be disclosed hereinafter. vTwo varcuateslots 16 and 17 are .locatedon the "bracket on either side of the collar .12. The bracket 11 .has the shape of asegment of a circle with sideedges .68and 69 at 136 to one another. vApivot point lug-21is located at the apex of the bracket .11, where'the two sides 68 and 69 meet.

Referencenumeral 15 indicates-a rectangularly shaped stationary table which has a laterally extending lug 20 which is bored to receive a bolt-.22. .The table 15 is .mounted on the underside of the bracket llby means of abolt 22 which passes through lugs 12%} and-21 and acts as a pointaround which the table 15 may bepivoted relative to the bracket 11. The table 15 is also clamped to thebracket by means of boltslS and 19 respectively,

-as.is seen in Figures .2 and 4.

The table 15 has wedge-shaped parallel tracks 23 and 24 on the lower face thereof defining arectangular cavity 47 therebetween, as seen in Figure 6.

-A sub-table 49 is :slidablymounted on the underside of table 15 by means of ways or tracks 50 and 51 which mate with the tracks 24 and 23, respectively of table 15.

An auxiliary spindle 62 is journalled on the sub-table 49 cross-wise thereof and parallel to the axis of the surface grinder spindle 29, as seen in Figures 1, 2 and "6.

A double sheave pulley 63 is mounted on the spindle 62 behind the grinding wheel 64.

Reference numeral 36 indicates a worm housing mounted on the top of the stationary table 15. A wormshaft 37 including a worm 33 is journaled in the housing 36 cross-wise of the table 15 and parallel to the spindle 29.

A crank shaft 40 is journaled in the housing 36'perpendicular to the table 15 and extending therethrough below the lower face thereof. A worm gear 41 engaged with the worm 38 is mounted on the shaft 40. The gear 41 is releasably secured to the crank shaft "49 through a clutch nut 43.

A first crank arm 44 is mounted on the lower end of the crank shaft 40 beneath the lower face of the stationary table 15. The crank arm 44 is, cylindrical in shape and :has a diametrical dovetail slot-45 cut in the bottom face thereof. as is seen most clearly in Figure 7. V

A pivot block 25 is slidably mounted in the slot 45. Reference numeral 27 indicates a pivot pin mounted on the block 25. Reference numeral 46 indicates an adjust; ment screw mounted in the crank arm and threadedly engaged with the pivot block 25. Rotation of the screw 46 in either direction acts to move the pivot block 25 longitudinally of the slot 45 toward or away from the center of rotation of the cylindrical crank arm 44-.

By providing a-screw- 46 with a fine thread, such as 40 to the inch, a very fine adjustment of the block is possible. A setscrew 26 can be brought to bear against the side edge of the block 25 to lock same against movement at the desired position. i

A second crank arm 53'is pivotally mounted on pin 54;, in spaced relation to the first crank arm 44, on the under side of the table 15,, as seen most clearly in Figures land 4. V

'The second crank arm 53 has a first 'stud 55 positioned proximate its pivot point 54, and second-stud dfi' posi tioned at the free end thereof.

A first connecting rod 57 the pivot pin 27 of the first crank arm 44 and the stud 55.

A second connecting rod 58 is pivotally mounted between the stud 56 of the second crank arm 53 and a pivot pin 59 mounted on the sub-table 49 is seen in Figures 2 and 4.

When the crank arm 44 is rotated, this double crank construction causes a relatively large movement of the second connecting rod 58 by a small movement of the first connecting rod 57. Thus twice the longitudinal movement of the table 49 can be effected with this construction without increasing the width of the slides beyond that used with the single crank construction described in my Patent No. 2,821,815.

A three sheaved pulley 60 is mounted on the surface grinder spindle 29.

One of the sheaves 61 is aligned with the worm pulley 39, while two sheaves 65 are aligned with the sheaves of the auxiliary pulley 63 mounted on the spindle 62.

Reference numerals 66 and 70 indicate driving belts connecting the pulley 60 and the worm pulley 39 and the grinding wheel spindle pulley 63, respectively.

These belts are made of material having an inherent natural rubber-like resiliency so that they can stretch and contract to hold the same tension as the centers of the various spindles move toward or away from one another as thesub-table 49 reciprocates as described hereinafter.

It will be evident that the auxiliary compound angle grinder 10, just described is an entirely self contained attachment that may be easily mounted or removed from an existing surface grinding machine in a matter of minutes.

. To set up the auxiliary grinder to cut a compound angle, the following procedure is used.

The collar 12 is loosened and the whole assembly 10 is swung around the surface grinder spindle housing 67 within an arc of plus or minus 15 degrees with reference to the vertical pointer 35, as indicated on the angle scale 13. The collar 12 is then locked at the desired setting by means of the bolt 14. This tilts the table 15 at an angle to the vertical.

The table 15 may then be pivoted laterally plus or minus 10 degrees by loosening the bolts 18, 19 and 22. The table 15 is then pivoted around the bolt 22 to either plus or minus 10 degrees as indicated by the scale 28 scribed on the top of table 15, as is seen most clearly in Figure 4. After the required setting is obtained, the bolts 18, 19 and 22 are drawn up thereby locking the table in angular disposition with reference to the bracket :11.

The spindle 29 is then started and the power transferred through belts 66 and 70 to the sub-table reciprocating mechanism and the auxiliary grinding wheel spindle 62 of the sub-table, respectively.

The length ofthe stroke of the table 49 is determined 2 by the position of the pivot block 25 with reference to the center of rotation of the first crank arm 44.

This is controlled within close limits by the adjustment screw 46 as described hereinabove.

The pivotal engagement of the first connecting rod 57 with the second crank arm 53 at a point 55 proximate its pivot pin 54 while the second connecting rod 58 is pivotally mounted on a stud 56 positioned at the extreme free end of the arm 53, provides a multiplying factor in the horizontal movement of the second connecting rod 58 for every unit of linear movement of the first connecting rod 57.

Thus double, or better, horizontal movement of the reciprocating sub-table 49 can be obtained without increasing the width of the tables beyond that of those defined in my above identified patent.

The work piece 34 is held stationary and the grinding wheel 64 is carried across the work face by the reciprocating table 49 which holds the grinding wheel 64 at the desired compound angle to the work piece 34.

As the grinding progresses, the work piece 34 i f d is pivotally mounted between ward toward the grinding wheel 64 to effect the depth of cut desired.

When the wheel 64 is to be dressed, the worm gear 41 is disconnected from the crank shaft 40 by loosening the clutch nut 43. The sub-table 49 will then be held stationary while the grinding wheel 64 rotates. By positioning the worm drive shaft 37 on the stationary table 15 the distance between driving spindle 29 and the driven shaft 37 remains constant so that there is no problem-of maintaining constant unvaried power transmission, as the subtable 49 reciprocates.

At the same time the inherent resiliency of the neoprene" belts 70 compensates for the varying center distances between spindles 29 and 62 as the table 49 reciprocates.

It will now be clear that there is provided a device which accomplishes the objectives heretofore set forth. While the invention has been disclosed in its preferred form, it is to be understood that the specific embodiment thereof as described and illustrated herein is not to be considered in a limited sense as there may be other forms or modifications of the invention which should also be construed to come within the scope of the appended claims.

I claim:

1. In combination with a surface grinding machine of the type having a grinding wheel spindle housing and a motor driven grinder spindle mounted therein, an auxiliary compound angle grinder, comprising, a bracket adapted to be mounted on the grinder spindle housing, including a stationary table, means for holding said stationary table in adjusted angular positions, both vertically and laterally with reference to the axial plane of the grinder spindle, a sub-table slidably mounted on the under side of said stationary table, an auxiliary spindle journaled on said sub-table and including a pulley and grinding wheel, a worm housing mounted on the stationary table, a worm shaft journaled therein and including a pulley, a pulley mounted on the grinder spindle having a first sheave aligned with the sub-table spindle pulley and a second sheave aligned with the worm shaft pulley, a separate resilient driving belt connecting each of the paired and aligned pulleys and sheaves, a crank shaft journaled in the stationary table perpendicular to the lower face thereof and including a worm gear engaged with the worm shaft, a crank arm mounted on said crank shaft below the stationary table and rotatable with the crank shaft, and a connecting rod pivotally connected at one end to the subtable and at the other end torthe crank arm, said connecting rod acting to reciprocate the sub-table longitudinally of the stationary table upon rotation of the crank arm.

2. In combination with a surface grinding machine of the type having a grinding wheel spindle housing and a motor driven grinder spindle mounted therein, an auxiliary compound grinder, comprising, a bracket adapted to be mounted on the grinder spindle housing and including a stationary table, means for holding said stationary table in adjusted angular positions, both vertically and laterally with reference to the axial plane of the grinder spindle, a sub-table slidably mounted on the under side of said stationary table, an auxiliary spindle journaled on said subtable, including a pulley and grinding wheel, a worm housing mounted on the stationary table, a worm shaft journaled therein and including a pulley, a pulley mounted on the grinder spindle having a first sheave aligned with the subtable spindle pulley and a second sheave aligned with the worm shaft pulley, a separate resilient driving belt connecting each of the paired and aligned pulleys and sheaves, a crank shaft journaled in the stationary table, perpendicular to the lower face thereof and including a worm gear engaged with the worm shaft, a first crank arm mounted on said crank shaft below the stationary table and rotatable with the crank shaft, a second crank arm pivotally mounted on the under side of the stationary table and spaced from said first crank arm, a first connecting rod pivotally connected at one end to the second crank arm proximate its pivot point and at the other end to the first crank arm, and a second connecting rod pivotally connected at one end to the sub-table and at the other end to the second crank arm at the free end thereof, said, several connecting rods acting to reciprocate the sub-table 4. An auxiliary compound grinder of the type defined in claim 2, and further distinguished by the first crank arm being cylindrical in shape with a diametrical dovetail slot cut in the lower face thereof, a pivot block, adapted to engage the end of the first connecting rod, slidably mounted in said slot, and threaded means on said crank arm engaged with said pivot block and adapted to move same longitudinally of the slot, between adjusted positions, with reference to the center of rotation of the 10 first crank arm.

References Cited in the file of this patent UNITED STATES PATENTS 2,821,815 Banko Feb. 4, 19 58

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