Dresser design

A dresser for roughening the surface of an abrasive wheel has a cutter means for rotation in contact with the abrasive wheel. The cutter means includes a plurality of cutter teeth mounted on a cutter shaft. Ball bearings at each end of the cutter shaft permit the cutter means to rotate freely when held against an abrasive wheel as the wheel is rotated. A pair of hexagonal bearing supports each define a bearing receiving recess for receiving the ball bearings mounted at each end of the cutter shaft. Each of the bearing supports also defines a threaded, bolt receiving opening. A dresser body defines a cavity receiving the cutter unit and slots on opposite sides of the cavity receiving the bearing supports. The dresser body has bolt holes extending from the exterior of the body into the cavity through each of the slots. The dresser body includes a dresser handle which permits the dresser to be manipulated manually. Cutter supporting bolts extend from the exterior of the dresser body through the bolt holes into the cavity and engage the threaded bolt receiving openings in the bearing supports. A pair of locating ridges on the exterior of the body extend parallel to the cutter shaft, permitting accurate location of the dresser on an abrasive wheel tool rest with respect to the abrasive wheel. In an alternative embodiment, a dresser mounting plate is pivotally attached to the dresser body and, further, pivotally attached to the abrasive wheel tool rest, such that the dresser may be quickly pivoted into position for dressing the abrasive wheel.

BACKGROUND OF THE INVENTION 
The present invention relates to a dresser for an abrasive grinding wheel 
and, more particularly, to a dresser having an improved bearing 
arrangement facilitating replacement of dresser cutter units. The dresser 
of the present invention facilitates positioning the dresser with respect 
to an abrasive wheel for rapid dressing of the wheel. 
Prior art dressers have generally included a dresser body upon which a 
cutter unit, including a plurality of sharp metal teeth, is rotatably 
mounted. The teeth of the cutter unit are relatively hard and, when held 
against a rotating abrasive wheel, tend to roughen, or dress, the wheel 
surface. 
Various bearing arrangements have been used to mount the cutter unit on the 
dresser body so that it may rotate freely when held against the abrasive 
wheel. A sleeve bearing arrangement, while simple to manufacture, is 
subject to rapid wear. As a consequence a dresser having a pair of 
hexagonal bearing supports, each such support including a plurality of 
sleeve bearing holes for receiving the shaft of a cutter unit, was 
developed. Such a dresser is shown in U.S. Pat. No. 1,382,176, issued June 
21, 1921, to Dobson. An improvement of this design is shown in U.S. Pat. 
No. 2,926,654, issued Mar. 1, 1960, to Johnston. The hexagonal bearing 
supports of Dobson and Johnston are held in slots on opposite sides of the 
dresser body and may be removed and reinserted into the body when it is 
desired to change the sleeve bearing holes in which the cutter unit is 
mounted. Although providing for improved bearing life over prior art 
sleeve bearing dresser designs, the sleeve bearings of Dobson and Johnston 
required frequent changing of the bearing holes being utilized as the 
holes became worn. 
Accordingly many prior art dressers utilized ball bearing support 
arrangements for mounting the cutter unit. Abrasive grinding wheel 
dressers having ball bearings for mounting the cutter unit, such as shown 
in U.S. Pat. No. 1,878,763, issued Sept. 20, 1932, to Dovell et al; U.S. 
Pat. No. 1,526,496, issued Feb. 17, 1925, to Hohnhorst et al; U.S. Pat. 
No. 2,742,891, issued Apr. 26, 1956, to Wise; and U.S. Pat. No. 1,805,514, 
issued May 19, 1931, to DeMattia, all included relatively complex mounting 
arrangements for holding the ball bearings in place in the body of the 
dresser. At the minimum, a number of screws would need to be removed from 
the dresser body in order to remove the bearings and cutter unit and 
substitute a new cutter unit. Further adjustments might also be required 
to set the cutter unit end play. 
Many grinding wheel dressers are hand held and positioned manually on the 
grinding wheel tool rest during the dressing operation. In order to 
facilitate positioning of the dresser with respect to the wheel and to aid 
the operator in holding the dresser in position during the dressing 
operation, dressers, such as shown in Dovell et al, supra, include a pair 
of feet extending laterally from the body of the dresser. The dresser is 
positioned on the tool rest such that these feet extend over the edge of 
the rest closest to the grinding wheel. The dresser may then be pivoted 
about this edge of the tool rest to bring the cutter unit into contact 
with the grinding wheel, while keeping the teeth of the cutter unit 
properly aligned with the grinding surface of the wheel. Where the tool 
rest has become uneven through wear and one of both of the feet are held 
in contact with an uneven portion of the rest, the dresser may be 
misaligned with respect to the abrasive grinding wheel. 
Other prior art dresser units have been permanently mounted on support 
structure adjacent the abrasive wheel, such that they may be pivoted into 
contact with the abrasive grinding wheel during the dressing operation. 
U.S. Pat. No. 272,615, issued Feb. 20, 1883, to Andrews; U.S. Pat. No. 
1,349,452, issued May 11, 1920, to Gorham; and U.S. Pat. No. 1,811,933, 
issued June 30, 1931, to Hohnhorst et al, all disclose dressers which are 
permanently mounted adjacent a grinding wheel. Such dresser mounting 
arrangements have typically hindered the operator in use of the grinding 
wheel and, therefore, have not been widely used. 
Accordingly, there is a need for an improved dresser utilizing ball bearing 
supports for the cutter unit and permitting the cutter unit to be changed 
rapidly and simply. Additionally, there is a need for an improved dresser 
permitting quick and accurate alignment of the cutter unit with respect to 
the grinding wheel. Also, a need exists for a dresser permanently mounted 
adjacent an abrasive grinding wheel which will not interfere with the use 
of the wheel. 
SUMMARY OF THE INVENTION 
A dresser for roughening the surface of an abrasive wheel includes cutter 
means for rotation against the abrasive wheel such that the wheel is 
dressed. The cutter means includes a plurality of cutter teeth mounted on 
a cutter surface. Ball bearing means are mounted at each end of the cutter 
shaft, permitting the cutter means to rotate freely when held against the 
abrasive wheel, as the wheel is rotated. A pair of polygonal bearing 
support means are provided with each support means defining a bearing 
receiving recess and a threaded, bolt receiving opening. Each of the 
bearing support means mounts one of the ball bearing means in the bearing 
receiving recess thereof. A dresser body defines a cavity receiving the 
cutter means, slot means on opposite sides of said cavity receiving said 
bearing support means, bolt holes extending from the exterior of the body 
into the cavity through each of the slot means, and a dresser handle. 
Cutter supporting bolts extend from the exterior of the dresser body 
through the bolt holes into the cavity and engage the threaded, bolt 
receiving openings in the bearing support means. 
The dresser body may further comprise a pair of locating ridges on the 
exterior of the body and extending parallel to the cutter shaft, whereby 
either of the locating ridges may be placed against the abrasive wheel 
tool rest for aligning the cutter means with the abrasive wheel. Such an 
arrangement provides for accurate positioning of the dresser, 
notwithstanding irregularities in the abrasive wheel tool rest. 
The dresser may also be pivotally attached to a dresser mounting plate 
which, in turn, is pivotally attached to the abrasive wheel tool rest such 
that the mounting plate may pivot about an axis which is perpendicular to 
the axis about which the dresser is pivoted with respect to the mounting 
plate. Such an arrangement permits rapid alignment of the dresser cutting 
means with respect to the abrasive wheel. 
Accordingly, it is an object of the present invention to provide a dresser 
for roughening the surface of an abrasive wheel in which the cutter means, 
supported by ball bearings, may be quickly and easily replaced; to provide 
such a dresser in which the dresser body includes a pair of ridges for 
engaging the wheel tool rest to align the dresser with respect to the 
abrasive wheel; and to provide such a dresser in which the dresser is 
permanently attached to support structure adjacent the wheel in a manner 
such that the dresser will not interfere with the use of the wheel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Reference is now made to FIG. 1 which is a perspective view illustrating 
the dresser of the present invention. A cutter means 10 is provided for 
rotation in contact with an abrasive wheel to dress the wheel. The cutter 
means includes a plurality of cutter teeth 12, illustrated 
diagrammatically, which are mounted on a cutter shaft 14. The specific 
design of the cutter teeth 12 does not form a portion of the present 
invention and any prior art cutter tooth design, such as shown for example 
in the Devell et al U.S. Pat. No. 1,878,763, may be employed. The cutter 
means may further include a pair of sleeves 16 (FIG. 2) which are pinned 
to the shaft 14 to hold the teeth 12 on the shaft 14 in a desired 
orientation. 
As seen in FIGS. 2 and 3, ball bearing means 18 are mounted at each end of 
the cutter shaft 14 to permit the cutter means 10 to rotate freely when 
held against a rotating abrasive wheel. A pair of polygonal bearing 
support means 20 each define a bearing receiving recess 22. The bearing 
support means 20 are shown as generally hexagonal in shape, although any 
polygonal shaped support, having opposite parallel sides, could be 
utilized. The bearing support means 20 each further define a threaded, 
bolt receiving opening 24. The ball bearing means 18 are pressed into the 
bearing receiving recesses 22 and dust slinger washers 26 are mounted on 
each end of the cutter shaft 14 for protecting the ball bearing means 18 
from abrasive particles removed from the surface of an abrasive wheel 
during the dressing operation. 
A dresser body 28 defines a generally semi-cylindrical cavity 30 for 
receiving the cutter means 10. Slot means 32 on opposite sides of the 
cavity 30 receive the bearing support means 20. Bolt holes 34 extend from 
the exterior of the body 28 into the cavity 30 through each of the slot 
means 32. A dresser handle 36 is provided so that the operator may firmly 
grasp the dresser during the dressing operation. Cutter supporting bolts 
38 extend from the exterior of the dresser body 28 through the bolt holes 
34 into the cavity 30 and engage the threaded bolt receiving openings 24 
in the bearing support means 20. Lock washers 39 may be positioned on 
bolts 38 between the bolt heads and the dresser body 28. 
The bearing arrangement illustrated in FIGS. 1-3 provides substantial 
improvement over ball bearing supports previously used in abrasive wheel 
dressers. As seen in FIG. 3, the polygonal bearing support means 20 
includes a forward extending portion 40 which provides a measure of 
protection to the bearings and the dresser body 28. Should the operator 
carelessly permit the bearing support arrangement to come into contact 
with the rotating abrasive wheel during a dressing operation, edge 40 will 
contact the wheel first, preventing the body 28 from being damaged. Bolts 
38 may thereafter be removed, allowing the bearing support means 20 to be 
removed from the slots 32, rotated, and reinserted into the slots. A new 
protective edge 40 will thus be provided should the bearing support means 
20 again come into contact with the abrasive wheel. 
It should be noted that only two bolts need be removed to permit the cutter 
means 10 to be replaced. Since the cutter shaft 14 slidably engages the 
ball bearing means 18, the cutter means may be removed from the ball 
bearing means 18 without the need for special tools. 
Further, the cutter supporting bolts 38 extend into the interior of the 
ball bearing means 18, with the length of the bolts 38 selected to provide 
a minimal clearance between the bolts 38 and the ends of shaft 14. Since 
the bolts 38 will be formed of a steel which is substantially harder than 
that from which the shaft 14 is formed, the clearance between the ends of 
the bolts 38 and the shaft 14 will define the maximum permissible end play 
for the cutter means 10. Any wear which may occur as a result of contact 
between the shaft 14 and the bolts 38 will occur on the ends of shaft 14. 
Thus when a new cutter means is inserted into the dresser, the bolts 38 
need not be replaced. 
The dresser body 28 further defines a pair of locating ridges 42 on the 
exterior of the body. These ridges extend parallel to the cutter shaft 14 
such that either of the locating ridges may be placed against an abrasive 
wheel tool rest for aligning the cutter means with respect to the abrasive 
wheel. This configuration is a substantial improvement over prior art 
dressers having only a pair of feet extending outwardly on one side of the 
dresser body. The dresser illustrated in FIGS. 1-3 may be placed on the 
abrasive wheel tool rest without regard to which side of the dresser is in 
contact with the tool rest. Further, the use of ridges 42 extending along 
the entire length of the dresser body permits the dresser to be aligned 
with the abrasive wheel properly, regardless of any irregularities in the 
tool rest surface. The ridges 42 will tend to bridge any such 
irregularities in the tool rest. 
Reference is now made to FIGS. 4-6, which illustrate an alternative 
embodiment of the present invention. The same cutter means, bearings, and 
bearing supports described with respect to FIGS. 1-3 are utilized in the 
alternative embodiment and, where shown, are given the same reference 
numerals. As seen in FIGS. 4 and 5, a dresser mounting plate 44 is 
provided for mounting the dresser body 28. Means for pivotally attaching 
the dresser body 28 to the mounting plate 44 such that the dresser body 
may be pivoted with respect to the mounting plate about an axis which is 
parallel to the cutter shaft includes a bolt 46 and a lock nut 47. A means 
for pivotally attaching the mounting plate 44 to abrasive wheel tool rest 
48 includes bolt 50 and a lock nut 52. The mounting plate 44 may therefore 
be pivoted, as shown in FIG. 4, about an axis which is perpendicular to 
the axis about which the dresser body is pivoted with respect to the 
mounting plate 44. As shown in FIG. 4, the mounting plate 44 may be 
pivoted to the position shown by the dashed lines such that the dresser 
will not interfere with the operator's use of the abrasive wheel 54. 
When the abrasive wheel 54 requires dressing, the plate 44 with the dresser 
pivotally mounted thereon is moved into the position shown in solid lines 
in FIG. 4 and dressing effectuated by pivoting the dresser about the bolt 
46, as shown in FIG. 5. The cutter means 10 of the dresser of FIGS. 4-6 is 
of sufficient width that it extends completely across the abrasive wheel 
54. 
As seen especially in FIG. 6, a pair of outwardly extending bosses 56 on 
the exterior of the dresser body 28 and a pair of bosses 58 on the 
mounting plate 44 each define a bolt hole through which the bolt 46 
extends. The lock nut 47 engages the end of the bolt 46 to secure the bolt 
in position. If desired, washers 62 may be positioned between bosses 56 
and 58 to facilitate pivoting of the dresser body 28. 
It will be appreciated that variations in the mounting arrangement 
illustrated in FIGS. 4-6 will come within the scope of the present 
invention. The mounting plate 44 may, for instance, be pivotally attached 
to a guard for the grinding wheel or other such structure. In such an 
arrangement, the dresser could pivot into position in contact with the 
abrasive grinding wheel at a point substantially above the point at which 
the wheel will contact a work piece supported by the tool rest 48. 
While the forms of apparatus herein described constitute preferred 
embodiments of the invention, it is to be understood that the invention is 
not limited to these precise forms of apparatus, and that changes may be 
made therein without departing from the scope of the invention.