Information
-
Patent Grant
-
6338672
-
Patent Number
6,338,672
-
Date Filed
Monday, December 21, 199826 years ago
-
Date Issued
Tuesday, January 15, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Ostrager; Allen
- Hong; William
Agents
-
CPC
-
US Classifications
Field of Search
US
- 451 56
- 451 443
- 451 444
- 451 268
- 451 269
- 451 291
-
International Classifications
-
Abstract
An apparatus for providing a flat to stepped convex facing for grinding wheels used for the finished machining of parts, the apparatus including dressing wheels located only at the outer diameter of the Cubic-Boron-Nitride wheels to be dressed.
Description
FIELD TO WHICH THE INVENTION RELATES
This invention relates to an improved apparatus for dressing fine grinding wheels utilized to smooth machine surfaces together with a method for utilizing same.
BACKGROUND OF THE INVENTION
Lapping and grinding machines have been utilized to manipulate the flatness of surfaces for subsequent use in mechanical and hydraulic mechanisms. The purpose of this manipulation operation is to make a surface of a part, typically metal, as smooth as possible. An example would be the opposing surfaces of the rotor utilized in the White Hydraulics, Inc. Motor as represented in White U.S. Pat. 5,135,369. In this example application, by flattening the opposing surfaces of the rotor, the volumetric and mechanical efficiency of the device can be increased by maintaining tighter spacing and tolerances between the flat surfaces of the rotor and adjoining surfaces of the motor housing.
In prior art two wheel grinding devices, a parts carrier assembly is located between two iron lapping wheels (it is called ‘lapping’ because the fine grinding particles are located in a surry and not the actual movable wheels). An example is the Hahn and Kolb Model ZL801 lapping machine. In this machine a carrier assembly consisting of a fixed outer stator, a driven inner pinion and toothed planet wheels are located between two iron lapping wheels. The parts to be lapped are located in sockets in the toothed planet wheels.
The iron lapping wheels themselves are initially dressed by a separate wheel dressing unit. The machine itself includes a source of the main cutting material, for example a silicon carbide surry, that accomplishes the actual lapping function. In the lapping operation, the devices typically operate under Rule 141 (New), double lap flatness of wheels. According to Rule 141, the flatness of the iron lapping wheels are periodically tested by the operator with a straight edge across the surface of each wheel. If one wheel is concave or low in the center, and the other wheel is convex or high in the center, then the wheels are run opposed to each other with the carrier run with the wheel which is low in the center. If both wheels are low in the center, both wheels and the center carrier are run in the same direction. If both wheels are high in the center, the wheels are run in the same direction with the carrier run in a direction opposed to the wheels. The actual rotational speed of the wheels is selected in consideration with the sizing of the work together with the amount of material to be removed.
Operations under Rule 141 require significant operator involvement in the operation of the machine and, in addition, typically an assistant to aid in the testing of the wheels to determine whether the wheels are low in the center or high in the center. In addition, the surry takes the same amount of material off of the iron lapping wheels as the parts being operated on by the machine.
The relative flatness of the lapping operation is thus normally interconnected with the tolerances of the machine together with the skill of the setup operator.
In respect to fine grinding wheels, it is necessary to periodically remove such wheels to flatten their grinding surfaces. This interrupts production while subjecting the grinding wheels to the risk of damage.
SUMMARY OF THE INVENTION
It is an object of this invention to improve the flatness of ground parts by dressing the grinding wheel.
It is an further object of this invention to reduce the cost of dressing grinding wheels.
It is another object of this invention to simplify the maintenance of grinding wheels.
It is yet another object of this invention to lower the tolerances of dressed grinding wheels and the parts manufactured thereby.
It is still a further object of this invention to increase the efficiency of manufacture of production parts.
Other objects of the invention and a more complete understanding of the invention may be had referring to the drawings in which:
DESCRIPTION OF THE DRAWINGS
FIG. 1
is a top view of a carrier dresser assembly built in accord with the invention;
FIG. 2
is a representational expanded perspective view of two Cubic-Boron-Nitride (CBN) wheels utilized in finishing the manufactured parts with the dresser assembly of
FIG. 1
in operational position;
FIG. 3
is a cross sectional side view of
FIG. 2
taken generally along lines
3
—
3
therein;
FIG. 4
is a top view of one of the planet dresser wheels of the dresser assembly of
FIG. 1
;
FIG. 5
is an enlarged view of the end of a CBN wheel in
FIG. 3
showing concave, tapered, and flat surfaces;
FIG. 6
is a view like
FIG. 1
of a part carrier assembly utilized in the manufacture of the manufactured parts;
FIGS. 7 and 8
are views like
FIG. 1
of alternate embodiments;
FIG. 9
is a representational cross section of a multiple stepped convex surface grinding wheel dresby the alternative of
FIG. 7
; and,
FIG. 10
is a representational cross section of a classical curved convex surface grinding wheel, this example dressed by the alternative of FIG.
8
.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to an improved dressing wheel together with the method of use therefor.
With grinding wheels, fine grinding particles (like CBN) are imbedded in the body of the wheels themselves. For this reason, it is called grinding not lapping. This has the advantage of eliminating the need for a cutting surry (although preferably a coolant such as oil is substituted for thermal stability). In addition, the fine grinding function occurs at room temperature while producing no sparks. However, using at least some grinding wheels (like CBN), the Rule 141 does not work making it necessary to totally remove the grinding wheels periodically, typically once a month or so, in order to separately dress them thus to compensate for any wear patterns which develop. This subjects the grinding wheels to the risk of damage (for example during removal and reassembly) as well as interrupting the production of finished parts on the machine.
In the present invention, the grinding wheels are dressed in place utilizing parts of the production assembly to a flat or convex grinding surface. For clarity, the invention will be described utilizing a two wheel fine grinding machine for power and control of the various elements disclosed herein. It is to be understood, however, that the general principals of the invention can be utilized in other machines as long as the principals set forth herein are incorporated.
In the present invention a dresser is differentially moved in respect to at least one grinding wheel, with the differential movement dressing the grinding wheel to have a flat to convex surface at least on the outer extent of the grinding surface for subsequent use in the manufacture of production parts. In general the faster the relative velocity between the dresser and the grinding wheel the quicker dressing will occur.
The differential movement can be provided by movement of the wheel, the dresser, or both as might be appropriate for the particular application. As it is preferred that the dressing occur with the grinding wheel mounted in place on the production manufacturing machine utilizing same, the existing controlled production movements can then be used to establish base parameters for the dressing operation. In addition change over time from production to dressing and back to production is significantly improved.
In the preferred embodiment utilized as an example herein, the production fine grinding machine has two fine grinding wheels
101
,
111
with imbedded cutting materials, which wheels are each independently operationally interconnected to two motors
102
,
112
(FIG.
3
). The axis of rotation of the wheels
101
,
111
, are aligned. A pinion
105
, driven by third motor
116
, is located between the wheels
101
,
111
, for relative rotation. All are supported by bearings (not shown) to a unitary frame (also not shown). This orientation allows for each fine grinding wheel
101
,
111
and the pinion
105
to be separately controlled in respect to both speed and direction of rotation. In certain other systems, differing drives and axis orientations could be utilized, for example a single motor for all moving parts in a dedicated machine, holding one grinding wheel stationary while moving the other, rotating the outer ring
110
instead of and/or in addition to the pinion
105
, or otherwise controlling the relative rotations of the parts therein.
In the particular embodiment disclosed, the two fine grinding wheels
101
,
111
are made of aluminum some 38″ in diameter having as cutting material CBN particles some 20 to 50 microns in diameter (the ISO 6106 DIN 848 nominal mesh is 180/150) suspended in a 3 mm thick plastic carrier at the surface of the wheels (FIG.
2
). The surface of the fine grinding wheels are interrupted by recessed slots
113
which, together with recessed inner edge
107
and outer edge
108
, facilitate the movement of coolant to the entire surface of the CBN wheels, and holes
114
which serve to help in draining off the coolant (the coolant shown is provided to the center of the upper fine grinding wheel
101
through a feed system
115
located generally thereat. Other coolant feeds could be utilized). The recessed inner edge
107
and outer edge
108
in addition create defined end locations for the actual CBN grinding surface, thus together with an over swept dressing action eliminating any inner and outer upwards extending lip problems (
FIGS. 5
,
9
,
10
) (i.e. the edges
107
,
108
are the lowest points of the CBN grinding carrier
117
, although they could be coextensive with the slots
113
if desired. In addition the surface could be segmented with edges
107
,
108
coextensive with the aluminum backing.).
This CBN fine grinding wheel is used by way of example and it is to be understood that other types of grinding materials (such as diamonds) and/or surfaces (such as a longitudinal planar surface) could be substituted.
In the invention of this application, the two fine grinding wheels
101
,
111
are dressed into a flat to convex shape, which shape has been ascertained to be the optimum for the flatness of resulting production parts and as having other advantages such as smoother production operation.
In the particular example shown, the fine grinding wheels
101
,
111
are dressed by a dressing wheel system
120
insitu on the fine grinding machine with the outer diameter of the fine grinding wheels corrected to produce a convex shape (see FIGS.
1
and
5
).
The dressing wheel system preferably includes certain operative parts of the grinding machine, in the example system
120
, parts of a planetary drive provide the dressing action. This envisions the use of the same pinion drive
105
and fixed outer ring
110
as the production part carrier assembly
150
utilizes, thus simplifying the assembly and disassembly of both the dressing wheel system and the production carrier system while interchanging between the two modes. Further, since removal of the grinding wheels
101
,
111
is not necessary and since no specialty fixture is utilized, overall cost and manufacturing efficiencies are increased with dressing and change over time reduced.
In the dressing wheel system
120
, the fixed outer ring
110
cooperates with the pinion drive
105
to operate the dressing wheel system
120
, in the preferred embodiment acting to provide for the double axis rotating motion of the planet dresser wheels
125
.
In the preferred embodiment disclosed, an enlarged intermediate pinion wheel
121
is located immediately surrounding the pinion drive
105
between such drive
105
and the planet dresser wheels
125
. This causes the planet dresser wheels to operate on the outer 20-40% extent of the fine grinding wheels
101
and/or
111
(33% shown) to facilitate the formation of the convex surface. The enlarged intermediate pinion wheel
121
also provides for significantly faster rotational speeds and velocity for the planet dresser wheels
125
about their own respective axis, thus providing for the potential of a more aggressive dressing operation.
Located immediately outward of the pinion extender gear
121
are the set of planetary dresser wheels
125
. These are preferably relatively small in size so as to increase their relative rotational speed or velocity in respect to a given rotational speed of the pinion drive
105
. In this respect note that due to the interaction of the parts of the system the relative velocity of the planet dresser wheels
125
can differ between the inside
123
and outside
124
of such wheels
125
. This allows for control of the nature of the shape of the fine grinding wheels
101
,
111
. The small size of the planet dresser wheels
125
also ensures that primarily the outer extent of grinding wheels
101
,
111
will be dressed thus to facilitate the convex shaping of the grinding wheels. The aggressiveness and the smoothness of the resulting surface is further facilitated by the optional use of later described inserts
126
spaced from the rotational center of the dresser wheels
125
, which inserts removes the plastic carrier allowing the CBN to break out faster during dressing.
After the surface to be dressed is determined to have the required initial shape, dressing with the planet wheels
125
is accomplished. During dressing, the dressing wheels
125
differentially move about the grinding wheels
101
,
111
to dress same. Note that in general, more surface dressed by the dresser wheels
125
per unit time, the quicker dressing will be finished. Due to this, the faster the planet dresser wheels
125
rotate in respect to a set length grinding surface, the faster dressing will occur. This is important in that in recognition of this, the differential movement does not have to be uniform between the two grinding wheels
101
,
111
. For example, if wheel
101
needed less dressing than wheel
111
to meet production standards, running wheel
101
at a rotational speed about the axis of the pinion more similar to that of the planet dresser wheels
125
than that of wheel
111
would reduce the dressing of wheel
101
compared to wheel
111
. (Note the same differential operation is true of the inserts
126
as well.)
Although this can be accomplished in many ways, it is preferred that the planet dresser wheels
125
move about the circumference of the fine grinding wheels
101
,
111
while also rotating about their own individual axis. This provides for a relatively uniform dressed surface (by reducing the effect of any out of standard component). In the example herein, this differential is provided by rotating the two fine grinding wheels
101
,
111
in the same direction as and at nearly the same speed as the pinion
105
(and thus also the extender
121
) with a slight upwards or downwards speed difference. This provides for an even dressed surface.
As the planet dresser wheels
125
pass over the fine grinding wheels, the fine grinding wheels
101
,
111
are dressed to the desired shape. In the preferred embodiment, this is a taper shape
133
to convex shape
130
, this in contrast with a concave surface
131
(shown in representational form in
FIGS. 5 and 10
respectively). Note that the convex shape
130
formed by the dresser of
FIG. 1
has a taper
133
(approximately 0.001″ over 4″ shown). This initial taper convex shape
133
is thus between a classical curved convex shape
129
and a flat surface
132
. This is in recognition that a taper or stepped flat surface can provide a convex surface for purposes of this invention.
Subsequent production operation of any embodiment will tend to blend this convex grinding wheel into a flatter and flatter shape to the surface determined by the user as a trigger redressing.
The convex shape on both wheels is preferred in that this provides the flattest resulting production parts during the later manufacture thereof. It also has the advantage of not causing the planet dresser wheels
125
(nor the parts in the planet part carriers
151
of the production carrier assembly
150
) to dig into the fine grinding wheels
101
,
111
when passing towards the outer edge thereof.
The dressing wheel system
120
can dress one, the other, or both of the fine grinding wheels
101
,
111
. This selective operation is produced by either selecting a set of planet dresser wheels
125
having diamond coating or other dressing material on one axial end or having such on both ends of the planet wheels
125
or by controlling relative rotation of the parts (as later described). The selective dressing could be provided by a multiple series of unitary dressing wheels having with each series having one of the above attributes (two series total) or by centrally split dressing wheels with each individual half section having a cutting material end and a non-cutting material end (one series with twice the number of parts). To minimize complexity of changeover, two series of unitary dressing wheels are preferred. Intermediate attribute dressing wheels
125
could also be utilized if desired.
In addition to the above, the movement of the fixed outer ring
110
upwards and downwards in respect to each individual fine grinding wheel
101
,
111
provides an additional control parameter by increasing or reducing the pressure of the planet dresser wheels
125
on the respective fine grinding wheel. Note that this upwards and downwards motion is not impeded by the grinding wheels
101
,
111
due to the fact that the inner circumferential edge of the outer ring
110
has a diameter greater than that of the grinding surface of the grinding wheels
101
,
111
(and in the example embodiment, beyond the entire wheels). This diametrical difference also allows the dresser planets
125
(and production parts in apertures
152
of the production assembly) to sweep up to and, as preferred, past the outer edge of the fine grinding wheels
101
,
111
.
In the present preferred embodiment, the dressing of the outer diameter of the wheels
101
,
111
and the speed of the dresser wheels
125
is provided by a single part, that of an intermediate pinion extender gear
121
which is located immediately outwards of the pinion drive
105
. This pinion extender gear
121
has the effect of markedly increasing the apparent diameter of the pinion drive
105
(over double—2.16 times), thus to locate the planet dresser wheels
125
at the outer extent of the grinding wheels, as well as increasing the amount of movement or velocity of the outer side
124
of the dresser gear
125
for a given speed of the pinion
105
. The pitch diameter of the extender gear
121
is selected in view of the desired convex shape for the dressed grinding wheels
101
,
111
. In general the point where the pinion gear
121
meets the inside
123
of the planet dresser wheel
125
defines the beginning of the convex shape, with the exact nature of such shape depending on the relative speeds and direction of rotation of the moving parts. For example as later set forth with the grinding wheels
101
,
111
and the pinion gear
121
running in the same direction at the same speed a taper convex shape is produced. The reason for the taper convex surface in the example is that the teeth at the inside
123
of the planet dresser
125
have substantially the same velocity of the interengaging teeth of the pinions gear
121
(and thus the CBN grinding wheels
101
,
111
.) This produces minimal dressing—V inner gear equals V planet dresser at this point. However the teeth at the outside of the planet dresser
125
have a much higher velocity. The reason for this is that the outside edge of the CBN grinding wheels have the highest velocity in the system. This in combination with the neighboring and engaged fixed ring gear
110
produces a more aggressive dressing operation for the planet dressers
125
at the outside
124
thereof, and thus the resultant taper.
The flat to convex shape of the dressed grinding wheels can be adjusted and/or modified by altering the relative differential between the dresser and grinding wheel, for example running the pinion gear
121
in the opposite direction at the same speed would produce a stepped convex shape. Thus the speed and direction of parts and relative velocity of the dresser planets
125
are inter-related.
The preferred taper
133
is created by the relative velocity of the planet dresser wheels
125
in respect to the CBN grinding wheels
101
,
111
. For example with the intermediate pinion wheel
121
driven in the same direction at the same speed as the grinding wheels, the inside
123
of the planet dresser wheel
125
will have a slower relative velocity than the outside
124
of such dresser wheel
125
. The reason for this is again that the inside
123
of the dresser wheel
125
is moving at a relative speed substantially equal to the intermediate pinion
121
(and thus the CBN grinding wheels) while the outside
124
of such dresser wheel
125
, being engaged with the stationary outer ring
110
, will be moving at a relative speed much higher than the CBN grinding wheels
101
,
111
. Due to this velocity difference the outside circumference of the grinding wheels is dressed more aggressively than inward thereof: hence the taper
133
.
The angularity of the taper can be controlled by the speed differential between the intermediate pinion
121
and the grinding wheels
101
,
111
. This controls the relative velocity of the dresser wheels
125
(and thus the aggressiveness of the dressing action). For example rotating the pinion
121
faster than the grinding wheels
101
,
111
would tend to more equalize the velocity differential between the inside
123
and outside
124
of the dresser wheels
125
, thus producing a lesser angle taper
133
(albeit with a slight step on the area inside that swept by the dressing wheels
125
if run long enough). Additional example by running the pinion
121
in the opposite direction as the CBN grinding wheels
101
,
111
the inside
123
will become as aggressive (if not more so) than the outside
124
of the planet dresser wheels
125
, producing a step convex shape
135
(FIG.
5
). Note that if each CBN grinding wheel
101
,
111
can be individually controlled, one can vary the aggressiveness of the dressing action differentially between such wheels. This is of benefit if one grinding has a more convex initial shape than the other grinding wheel (the former needing less dressing than the latter and thus a lesser velocity between the planet dresser wheel and the grinding wheel).
The present invention utilizes planet dresser wheels
125
which rotate about the axis of the pinion drive
105
at speeds different than that of the CBN fine grinding wheels
101
,
111
about their respective axis in order to provide for an aggressive cut. Further, this aggressive cut is accomplished primarily on the outside diameter of the CBN fine grinding wheels so as to provide for two convex wheels, thus eliminating the need to compensate for possible differing shapes (concave/convex) of two fine lapping wheels during production as was done under Rule 141 (previously described), while also eliminating the need to remove the CBN wheels to grind them flat (as previously required since Rule 141 does not satisfy the maintenance needs of fine grinding wheels).
The particular fixed outer ring
110
has a pitch diameter of 38.97″ with 336 inner teeth, the pinion drive
105
has a pitch diameter of 13.46′ with
114
outer teeth, the enlarged pinion wheel
121
has a pitch diameter of 29.05″ with 246 outer teeth, and the planet dresser wheels
125
have a pitch diameter of 4.96″ with 42 outer teeth. (The production planet part carriers
151
have a pitch diameter of 12.76″ with
108
outer teeth and the apertures
152
therein are 4.63″ in diameter.) The inserts
126
are 2.5″ in diameter. The example dressing action occurs with both the pinion
121
and CBN grinding wheels
101
,
111
rotating in the same direction at approximately 70 RPM. Dressing is complete in substantially three seconds producing a taper of some 4″ in length having a drop from 0.001 to 0.003″ from the outside of the CBN grinding wheels
101
,
111
to the inside
123
of the planet dresser wheels
125
.
The dresser wheels
125
may be used by themselves or in conjunction with one or more inserts
126
, which inserts
126
are utilized in the preferred embodiment to remove some of the carrier holding the cutting material to initially define a flat to convex shape.
The dresser wheels
125
are used by themselves when a simple dressing is necessary to produce the desired convex shape. For example if in the preferred embodiment after dressing the plastic matrix and CBN have an acceptable length of usability for the subsequent production operation after dressing while still maintaining the preferred convex shape. For consistency, it is preferred that the standard for this “simple dressing” reflect a pre-established objective criteria such as number of parts able to be ground in subsequent production, [matrix] thickness drop over the convex shape, time of previous (or subsequent) grinding operation, etc. This would simplify dressing and subsequent manufacturing production by allowing a uniform procedure to be followed. This would tend to reduce operator error, tolerance deviances, and other problems.
If the convex shape is less than a sufficient amount on the area to be dressed, for example the selected standard, inserts
126
are inserted into the dresser wheels
125
. The purpose of these inserts
126
is to initially remove the carrier and some of the cutting material, thus to initially shape the grinding wheels to a convex shape. To accomplish this, it is preferred that the inserts
126
have a height greater than that of the dresser wheels
125
together with a hardness greater than the carrier but less than that of the cutting material. These attributes would allow the inserts
126
to act on the carrier independently of the dressing material on the dresser wheels
125
(due to the height differential) while removing the carrier without substantive compromising harm to the cutting material like CBN embedded therein (due to the relative hardness). The number of inserts utilized preferably is selected dependent on the amount of carrier to be removed: The less material to be removed, the greater the hardness of the inserts and, the slower the speed of the inserts, the fewer the number of inserts need be utilized.
The exact initial shape defined by the inserts
126
is dependant on the location and relative velocity thereof. In general, as previously set forth in respect to the planet dresser wheels
125
the higher the relative velocity of the inserts
126
in respect to the fine grinding wheels
101
,
111
the more material will be removed per unit time. However, this should be tempered with a recognition of the more central location of the inserts
126
in respect to the planet wheels
125
as well as that the softer plastic carrier breaks out faster than the CBN grinding material. For this reason the inserts
126
tend to create more of a stepped surface than a taper in this initial shaping—i.e. the relative hardness overcomes velocity differential.
The use of the inserts
126
can be before, after, or intermediate dressing by dresser wheels
125
. Further again, one or both wheels
101
,
111
can be subject to the inserts
126
(having differing hardness between the axial ends of integral inserts
126
, or by splitting same into two differing hardness parts and/or differing relative velocities can be used to provide differential initial carrier removal between the grinding wheels
101
,
111
.). As with the planet dresser wheels, two series of inserts are again preferred.
In the preferred embodiment, the surface of the grinding wheels
101
,
111
are preferably dressed at or before when such surface is flat and smooth. At this time, if necessary the inserts
126
of RC 66 aluminum oxide are utilized until approximately 30% to 66% of the diameter of the CBN cutting material is left exposed and the desired convex shape is initially produced in the plastic carrier. This gives a surface substantially equal to 100 grit sand paper prior to dressing by the dressing wheels
125
. After a sufficient amount of the cutting material is exposed, it is preferred that the inserts
126
be removed. This allows that height differential between such inserts
126
and the dresser wheels
125
be maintained for subsequent use of such inserts
126
. The grinding wheels
101
,
111
are then dressed by the planet dressers
125
to the preferred convex shape.
Upon completion of the dressing operation (i.e., preferably both fine grinding wheels
101
,
111
being convex), the planet dresser wheels
125
and intermediate pinion extender gear
121
are removed from the machine and a production carrier assembly
150
substituted.
In the example utilized herein this production carrier assembly
150
includes the pinion drive
105
, six intermediate toothed part carriers
151
and the fixed outer ring
110
. As the pinion drive
105
and fixed outer ring
110
are also utilized in the dressing wheel system
120
the change over is easily accomplished with minimal concern for tolerances.
After the assembly of the production carrier
150
, the parts to be ground are inserted in the apertures
152
present in these part carriers
151
so as to pass them over the CBN dressing wheels in the double rotating manner inherent in a planetary type device. This production operation continues until dressing is again needed, at which time the dressing wheel system
120
is reassembled.
Although the invention has been described in its preferred form with a certain degree of particularity, it is to be understood that changes can be made deviating from the invention as hereinafter claimed. For example, it is possible to utilize all of the production part carrier assembly
150
for dressing the grinding wheels, for example inserting dressing wheels in one or all of four (A, B, C, D) of the four apertures
152
(and if appropriate inserts) therein. This would, however, necessitate an additional step of warping the grinding wheel to produce a concave shape
131
(for example by temporarily shimming the outer circumference thereof downward during dressing) in order to dress the preferred outer radial extent of such grinding wheels to produce a convex surface. With stationary carriers
151
and rotating grinding wheels
101
,
111
, alternately as the apertures
152
go outwards from C to B to A, more aggressive dressing materials could be utilized in the apertures. Without either of these options, a flat grinding surface would be produced due to the rotation of the carriers
151
in respect to the grinding wheels
101
,
111
. Additional examples a pinion extender
140
A having multiple pockets
141
can be assembled about the pinion
105
out of contact with the surrounding fixed ring gear
110
(FIG.
7
). Dresser wheels
125
A would be inserted into the pockets
141
so as to dress the grinding wheels
101
,
111
. With all pockets occupied, this alternative produces substantially the grinding wheel surface of FIG.
9
. Note that the pockets
141
shown are arranged into three offset rows, with each row at least extending to touch the area swept by an adjoining row. By varying the number and location of the dresser wheels
125
A the amount and location of dressing can be adjusted. As previously set forth in respect to the preferred embodiment it is preferred that the outre radial extent of the grinding wheels be dressed to a convex shape, in general more dresser wheels
125
A would be inserted in the outer row
142
than any other. The middle and inner rows
143
,
144
are preferably more for maintenance of the inner surface of the grinding wheels
101
,
110
and would thus normally utilize a lesser number of dresser wheels
125
A (if any). A further alternative would be to make the dressing materials integral with a modified no-pocket pinion extender platter
140
B having two concave surfaces, one for each grinding wheel
101
,
111
, again out of contact with the outer ring
110
—i.e. it is not necessary to use separate dresser wheels
125
A). This would form the preferred convex grinding surfaces utilizing a single additional member
140
A in combination with existing production assembly parts. This alternative would produce the grinding wheel surface of FIG.
10
. The extent of the dressing materials would again be selected to provide the preferred dressing operation. Therefore many changes can be made without deviating from the invention as herein after claimed.
Claims
- 1. In a system utilizing a fine grinding wheel, the wheel having a fine grinding surface with an outer extent neighboring an outside circumference,the improvement of a dressing wheel system, the dressing wheel system including dressing material, means to bring said dressing material and the outer 20-40% extent of the fine grinding surface into physical contact, and differential movement means to provide differential movement of said dressing material relative to the fine grinding surface to provide a convex shape to the outer 20-40% extent of the fine grinding surface.
- 2. The system of claim 1 characterized by means to flex the outside extent of the grinding surface to form a concave surface during operation of said differential movement means.
- 3. The system of claim 1 wherein the system has a production assembly and characterized in that said differential movement means utilizes at least part of the production assembly.
- 4. The system of claim 1 characterized in that said differential movement means includes planet gears.
- 5. The system of claim 4 wherein the system includes a production assembly having a pinion drive gear and characterized by said differential movement means of said dressing wheel system utilizes the pinion drive gear.
- 6. The system of claim 1 wherein the system includes a production assembly having a pinion drive gear and characterized by said differential movement means of said dressing wheel system utilizes the pinion drive gear.
- 7. The system of claim 6 wherein the pinion drive has a gear with a diameter and characterized in that said differential movement means includes an intermediate pinion extender gear, and said extender gear increasing the apparent diameter of the pinion drive pear.
- 8. The system of claim 1 wherein there is a production system using the dressing wheel has a stationary outer ring and characterized by said movement means utilizes the stationary outer ring.
- 9. The system of claim 1 wherein the system includes a production assembly having a pinion drive gear having a diameter and a fixed outer ring, and characterized by said differential movement means of said dressing wheel system utilizing the pinion drive gear,said differential movement means also including an intermediate pinion extender gear, said extender gear increasing the apparent diameter of the pinion drive gear, said differential movement means utilizing the stationary outer ring, planet dresser wheels, means to connect said dressing material to said planet dresser wheels, and said planet dresser wheels being drivingly located between said extender gear and the stationary outer gear.
- 10. The system of claim 1 wherein the fine grinding surface is formed of cutting materials embedded in plastic and characterized by the dressing wheel system including removal means to remove the plastic to expose the cutting materials.
- 11. The system of claim 10 characterized in that said differential movement means includes planet gears and means selectively to insert said removal means to said planet gears.
- 12. The system of claim 11 characterized in that said planet gears have a rotational axis and said removal means being substantially displaced from said rotational axis.
- 13. The system of claim 1 characterized in that the fine grinding surface is dressed to a convex shape.
- 14. The system of claim 13 characterized in that said convex shape includes a taper.
- 15. The system of claim 14 characterized in that said convex shape includes at least one step.
- 16. The system of claim 13 characterized in that said convex shape is a curved shape.
- 17. In a system utilizing a fine grinding wheel, the wheel having a fine grinding surface with an outer extent neighboring an outside circumference, the system having a production assembly including planet gears and a pinion drive gear,the improvement of a dressing wheel system, the dressing wheel system including dressing material, means to bring said dressing material and the outer 20-40% of the outer extent of the fine grinding surface into physical contact, differential movement means to provide differential movement of said dressing material relative to the fine grinding surface relative to provide a convex shape to the outer 20-40% of the outer extent of the fine grinding surface, and said differential movement means utilizing at least part of the production assembly and the pinion drive gear.
- 18. The system of claim 17 wherein the pinion drive has a diameter and characterized in that said differential movement means includes an intermediate pinion extender gear, and said extender gear increasing the apparent diameter of the pinion drive gear.
- 19. The system of claim 18 wherein the production assembly has a stationary outer ring and characterized by said differential movement means utilizes the stationary outer ring.
- 20. The system of claim 17 wherein the production assembly has a stationary outer ring, and the pinion drive gear has a diameter, and characterized by said differential movement means of said dressing wheel system utilizing the pinion drive gear,said differential movement means also including an intermediate pinion extender gear, said extender gear increasing the apparent diameter of the pinion drive gear, said differential movement means utilizing the fixed outer ring, planet dresser wheels, means to connect said cutting material to said planet dresser wheels, and said planet dresser wheels being drivingly located between said extender gear and the stationary outer gear.
- 21. The system of claim 17 wherein the fine grinding surface is formed of cutting materials embedded in plastic and characterized by the dressing wheel system including an insert removal means to remove the plastic to expose the cutting materials prior to the dressing thereof.
- 22. The system of claim 21 characterized in that said differential movement means includes planet wheels and means selectively to connect said insert removal means to said planet wheels.
- 23. The system of claim 22 characterized in that said planet wheels have a rotational axis and said insert removal means being substantially displaced from said rotational axis.
- 24. The system of claim 17 characterized in that said convex shape includes a taper.
- 25. The system of claim 24 characterized in that said convex shape includes at least one step.
- 26. The system of claim 17 characterized in that said convex shape is a curved shape.
- 27. In a system utilizing a fine grinding wheel, the system including a production assembly having a pinion drive gear having a diameter and a stationary outer ring,the wheel having a fine grinding surface with an outer extent neighboring an outside circumference, the fine grinding surface is formed of cutting materials embedded in plastic, the improvement of a dressing wheel system, the dressing wheel system including dressing material, means to bring said dressing material and only the outer 20-40% extent of the fine grinding surface into physical contact, differential movement means to provide differential movement of said dressing material relative to the fine grinding surface to provide a flat to convex shape to the outer 20-40% of the fine grinding surface, said differential movement means of said dressing wheel system utilizing the pinion drive gear, said differential movement means also including an intermediate pinion extender gear, said extender gear increasing the apparent diameter of the pinion drive gear, said differential movement means utilizing the stationary outer ring, planet dresser wheels, means to connect said cutting material to said planet dresser wheels, said planet dresser wheels being drivingly located between said extender gear and the stationary outer gear, insert removal means to remove the plastic to expose the cutting materials, means selectively to insert said insert removal means to said planet dresser gears, said planet dresser gears having a rotational axis and said insert removal means being substantially displaced from said rotational axis.
- 28. A method for dressing a fine grinding wheel, the wheel having a fine grinding surface with a radial extent to an outside diameter, method comprising bringing dressing material and the outside diameter of the fine grinding surface into physical contact with said dressing material having a radial extent less than the radial extent of the fine grinding surface,and moving said dressing material and the fine grinding surface relative to one another to provide a flat to convex shape to the fine grinding surface.
US Referenced Citations (11)
Foreign Referenced Citations (1)
Number |
Date |
Country |
59-81054 |
May 1984 |
JP |