U.S. patent number 3,665,650 [Application Number 04/868,397] was granted by the patent office on 1972-05-30 for abrasive belt control apparatus and method.
This patent grant is currently assigned to Murray-Way Corporation. Invention is credited to Witold C. Przygocki.
United States Patent |
3,665,650 |
Przygocki |
May 30, 1972 |
**Please see images for:
( Certificate of Correction ) ** |
ABRASIVE BELT CONTROL APPARATUS AND METHOD
Abstract
Apparatus and method for use with an endless abrasive belt
operable to sense the position of the belt and to automatically
oscillate the belt transversely in accordance with movement of a
position sensor.
Inventors: |
Przygocki; Witold C.
(Southfield, MI) |
Assignee: |
Murray-Way Corporation
(Birmingham, MI)
|
Family
ID: |
25351591 |
Appl.
No.: |
04/868,397 |
Filed: |
October 22, 1969 |
Current U.S.
Class: |
451/1; 451/297;
451/304 |
Current CPC
Class: |
B24B
21/18 (20130101) |
Current International
Class: |
B24B
21/00 (20060101); B24B 21/18 (20060101); B24b
021/00 () |
Field of
Search: |
;51/135,135BT,142 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Armstrong; William R.
Claims
What is claimed is:
1. In an endless abrasive belt supported for translational movement
on a pair of spaced support rollers, apparatus for causing
controlled movement of the belt transversely to its direction of
translational movement, said apparatus comprising: sensor means
movably supported relative to one edge of said belt for providing a
first output signal when the belt and said sensor are in first
determinable positions relative to each other; first means
drivingly connected to said sensor means for cylically displacing
said sensor means in a first direction between first and second
spaced, transversely located points; and second means responsive to
said output signal for effecting transverse movement of the belt in
said first direction whereby the belt will substantially track the
movement of said sensor means as it is displaced in said direction
between said first and second points.
2. The apparatus of claim 1 with said second means effecting the
transverse movement of the belt in the opposite direction in
response to a second control signal, said sensor means providing
said second control signal with the belt and said sensor means are
in second determinable positions relative to each other.
3. The apparatus of claim 2 with said first means including drive
means connected to said sensor means for moving said sensor means
in said one and opposite directions in a preselected manner between
said first and second spaced transversely located points.
4. The apparatus of claim 3 with said sensor means comprising a
fluidic sensing member operable from a source of pneumatic
pressure.
5. The apparatus of claim 4 with said sensor means including an
aperature normally located in confrontation with the belt and with
said first and second determinable positions being determined by
the position of the aperature relative to the belt.
6. The apparatus of claim 1 with said second means comprising
piston means actuable in response to said first signal to pivot one
of the support rolls.
7. The apparatus of claim 6 with said second means comprising
balancing means for reacting the force of said piston means.
8. The apparatus of claim 6 with said sensor means comprising a
fluidic sensor operable from a source of pneumatic pressure and
with said piston means actuable from the same source.
9. The apparatus of claim 8 with said sensor means including an
aperature normally located in confrontation with the belt and with
said first determinable positions being determined by the degree of
direct confrontation of the aperature with the belt with said first
signal being a pressure having a magnitude varying with the
magnitude of said degree of confrontation and with the pressure to
said piston means varying in accordance with the magnitude of said
first signal.
10. The apparatus of claim 9 with said second means comprising
balancing means for reacting the force of said piston means.
11. The method of grinding a workpiece with an endless abrasive
belt supported for translational movement on a pair of spaced
support rollers, comprising the steps of providing an output signal
by means of sensing apparatus movably located relative to one edge
of the belt, driving the sensing apparatus between first and second
spaced transversely located points, moving the belt transversely
relative to the rollers in response to the output signal, whereby
the belt will generally track the movement of the sensing
apparatus.
12. The method of claim 11 further comprising the steps of
utilizing a belt for grinding a workpiece surface which surface is
substantially wider than than the width of the belt and moving the
sensing apparatus to cause the belt to traverse over the complete
width of the workpiece surface.
13. The method of claim 11 further comprising the steps of
utilizing a belt for grinding a workpiece surface which surface is
substantially narrower than the width of the belt and moving the
sensing apparatus to cause substantially the entire width of the
belt to traverse over the workpiece surface.
14. In an endless abrasive belt supported for translational
movement on a pair of spaced support rollers, apparatus for causing
translational movement of the belt transversely to its direction of
translational movement, said apparatus comprising: a sensor
operable from a source of pneumatic pressure and movably supported
relative to one edge of said belt for providing a first output
signal when said sensor confronts a surface of the belt and a
second signal when said sensor is spaced outside of the surface of
the belt, drive means connected to said sensor for continuously
displacing said sensor between first and second transversely spaced
points; and second means operable from said source of pneumatic
pressure and responsive to said first output signal for effecting
transverse movement of the belt in a first direction and to said
second output signal for effecting transverse movement of the belt
in an opposite transverse direction.
15. The apparatus as set forth in claim 14 wherein said drive means
includes an adjustable speed drive motor for displacing said sensor
in said first and opposite direction.
Description
SUMMARY BACKGROUND OF THE INVENTION
The present invention relates to apparatus for controlling the
oscillatory movement of an endless abrasive belt.
In the past, apparatus has been provided for endless abrasive belts
to automatically oscillate the belt transversely to its direction
of travel. This prevents the belt from "walking" off the support
rolls and tends to improve belt life, i.e. by more evenly
distributing wear. With past constructions, the oscillation or
transverse motion of the belt has been generally fixed. In the
present invention a sensor is utilized which senses the position of
the belt; the sensor is selectively oscillated and apparatus which
is responsive to the sensor causes similar oscillation or tracking
of the belt; In this manner the oscillatory motion of the belt can
be controlled simply by selectively controlling the oscillatory
action of the sensor. Therefore, it is an object of the present
invention to provide novel apparatus and method for controlling the
movement of an endless abrasive belt.
In present grinding techniques normally a belt is used which is
approximately as wide as the workpiece to be ground. For extremely
wide workpieces the belt is correspondingly wide and hence costly.
In the present invention by use of the selective controlled
oscillation the belt can be narrower and can be moved over a
substantial distance to cover the width of the workpiece. Thus a
substantial savings in the cost of the belt can be realized.
Conversely a belt wider than the workpiece could be tracked to
grind a narrow workpiece resulting in a more effective utilization
of the belt. It is therefore another object of the present
invention to provide novel apparatus and method for oscillating a
belt on a support roll whereby a wide workpiece can be ground by a
substantially narrower abrasive belt and conversely where wide belt
can be more effectively utilized on a narrow workpiece.
Other objects, features, and advantages of the present invention
will become apparent from the subsequent description and the
appended claims, taken in conjunction with the accompanying drawing
in which:
FIG. 1 is a front elevational view of apparatus embodying features
of the present invention;
FIG. 2 is a side elevational view of the apparatus of FIG. 1;
and
FIG. 3 is generally a schematic diagram of the apparatus of FIG. 1
and 2.
An abrading belt assembly is generally indicated by the numeral 10
and includes an endless abrasive belt 12 supported for movement on
spaced rolls 14 and 16. The roll 16 can be driven by a motor 18,
the actuation of which can be controlled by a motor control
apparatus 20. Roll 16 is a contact roll and is generally fixed
relative to the assembly 10 and backs up the abrasive belt 12 as it
engages a workpiece. The roll 14 is a control and belt tension roll
with the tension being selectively adjustable on the belt 12 by
means of a belt tension cylinder assembly 22. The cylinder assembly
22 is fixed to a bifarcated frame 24 upon which the contact roll 16
is journaled. The control roll 14 is journaled upon a different
bifarcated frame assembly 26 which is connected to the piston rod
28 of the piston assembly 22 whereby the frame 26 and hence the
control roll 14 can be pivoted relative to the axis X of the rod 28
in a manner to be described.
Supported upon the frame 26 is an adjustable speed drive motor 30
which is connected to a sensor assembly 32 via a linkage assembly
34. The sensor assembly 32 is mounted for translatory and
transverse motion relative to the belt 12 and to the roller 16 by
means of a pair of guide or support rods 36 which are fixed to the
frame 26. A sensor assembly 32 includes a fluidic sensor having an
aperture 38 which is located approximate to and generally in
confrontation with the back surface of the belt 12 such that air
flow out from the opening 38 would be generally directed towards
the back surface of the belt 12. A flexible hose 40 connects the
sensor assembly 32 to a source of air pressure via a fluid line 60
and a flow regulator 43.
An actuating piston assembly 42 is fixed to a first cross bar 44
and located such that the rod of its actuating piston 46 can engage
the lower end of one arm 47 of the control roll support frame 26.
The bar 44 is fixed to the frame 24 such that the piston assembly
42 will be maintained stationary relative to any pivotal movement
of the control roll 14 and support frame 26 relative to the axis of
the piston rod 28. Thus the force from piston 46 will tend to pivot
the control roll 14 about the axis X of piston rod 28. Oppositely
facing the piston assembly 42 is a balance assembly 48 which is
fixed to a support bar 50 which support bar 50 is also fixed to the
frame 24. The balance apparatus 48 includes a moveable plunger 52
which is normally biased via spring 54 outwardly into engagement
with the opposite side of arm 47 on frame 26. The bias of spring 54
can be set by a moveable plug 56. The force of the plunger 52
acting upon the frame 26 will tend to pivot the control roll 14
about the axis X of piston rod 28 in a direction opposite to that
resulting from the force exerted by piston 46 and hence will react
the force from piston 46. The piston 46 is normally returned to its
deactuated position by means of a spring member 49. The piston 46
is actuated by air pressure on the head side via a conduit 58 which
is also connected to the regulator 43 via the common fluid line 60.
The regulator 43 provides for a generally constant flow of air such
that the pressure in the cylinder of the piston assembly 42 will be
a function of the flow through the orifice 38.
Normally in operation, the edge of the belt 12 is located such as
to be partially blocking the aperture 38. In this condition, the
flow of fluid out from the aperture 38 will be reduced resulting in
a pressure rise in the cylinder assembly 42 causing the piston 46
to move outwardly to pivot the control roll frame 26 and hence the
control roll 14 about axis X. This causes the belt 12 to twist
slightly increasing the pressure on its outer most edge causing the
belt 12 to move in a direction away from the opening 38 as the
rolls 14 and 16 rotate. Looking now to FIGS. 1 and 2 for example,
if the fluid sensor assembly 32 is moved to the right along the
guide rods 36, the opening 38 will continuously be moved in the
direction to be at least partially blocked by the black of the belt
12. The result will be pressurization of the cylinder assembly 42
whereby the piston 46 will be actuated to pivot the control roll 14
to twist of belt 12 causing the belt 12 to be moved transversely to
the right along the control roll 14. This motion will continue at
least until the belt 12 exposes a sufficient portion of the
aperture 38 such that the pressure in the piston assembly 42 will
be reduced and the face of piston 46 balanced or overcome by the
balance force of the spring loaded plunger 52. The motion of the
sensor assembly 32 is controlled by the adjustable speed gear motor
30 via the linkage 34 such that its transverse motion will continue
in a selected or programmed manner resulting in selective movement
of the belt 12 to the right. At the end of the stroke of linkage
34, the motion of sensor 32 will be reversed and it will be moved
toward its original position at the left. As this occurs, the
opening 38 will be moved in the direction tending to expose the
aperture 38 resulting in a loss of pressure in the cylinder
assembly 42 resulting in the control roll 14 and control roll frame
26 being pivoted in an opposite direction whereby the belt 12 will
be oppositely twisted and will move to the left. Note that in this
way the belt 12 can be automatically oscillated transversely across
the control roll 14 and contact roll 16 in accordance with the
speed and type of motion selected for the sensor assembly 32; in
the example shown this is determined by the motor 30 and linkage
34.
The apparatus in the embodiments of FIGS. 1 and 2 are shown
schematically in FIG. 3. It can be seen that with the apparatus
shown a simple means can be used to control the transverse motion
of a belt and with this apparatus a relatively narrow belt can be
used to grind or finish a wide workpiece obviating the need for
wider, more expensive belts.
While it will be apparent that the preferred embodiments of the
invention disclosed are well calculated to fulfill the objects
above stated, it will be appreciated that the invention is
susceptible to modification, variation and change without departing
from the proper scope or fair meaning of the invention.
* * * * *