CROSS-REFERENCE TO RELATED APPLICATION
FIELD
[0002] The present disclosure relates to adjustable orbital devices including, but not limited
to polishers, buffers, sanders and massagers.
BACKGROUND
[0003] The present disclosure relates to an apparatus for adjusting the stroke of random
orbital machine, such as, but limited to, polishing machines, sanding machines and
massaging machines. The adjustability allows the user to define the stroke of the
random orbital machine and adjust it between a maximum definitive stroke setting and
a minimum 0 orbital setting.
[0004] Polishing machines and sanding machines are routinely used in the automotive detailing
industry and home building industry to correct imperfections in the paint or drywall
and to apply polishes and waxes. There are three primary machines used, including
rotary buffers, random orbital machines, and dual action machines. Each tool has its
place, as the manner in which the pad spins on each machine is unique and used for
different purposes.
[0005] Rotary buffers are the fastest and most effective machine for removing paint defects
in a controlled manner with good results. The drive unit used in a rotary buffer is
directly connected to the pad and each one is in axial alignment with each other.
In order to correct paint scratches, the rotary buffer is commonly used to remove
enough paint surrounding the scratches to make the surface level. Removing scratches,
however, requires more skill and control of the machine than a typical hobbyist possesses.
For this reason, rotary buffers are commonly avoided by average users as it is very
easy to remove too much paint and damage the finish by causing swirl marks or by burning
the paint.
[0006] Random orbital machines were introduced in order to meet the needs of an average
user, as they require less experience and control to operate. A random orbital machine
uses a gear case that employs two unique mechanisms which move a pad attached to a
backing plate. Unlike a rotary buffer, random orbital machines place the central rotational
axis of the pad and the backing plate offset from the driveshaft of the machine. This
offset is commonly referred to as the "stroke". As a result, the backing plate and
pad orbit the driveshaft in a circular motion. At the same time, the pad randomly
spins, as it is mounted on an idle bearing. This random spinning varies with pressure
applied on the pad and is not directly powered. The result is a polishing action that
will not burn or cut through the paint as it will not produce the heat from a powered
spinning action. Random orbital machines are, therefore, much safer and dramatically
less likely to cause swirls or burn through the paint.
[0007] Similar to random orbital machines, dual action machines place the central rotational
axis of the pad and the backing plate offset from the driveshaft. As a result of this
stroke, the backing plate and pad orbit the driveshaft in a circular motion. However,
with a dual action machine the spinning of the pad is directly powered.
[0008] At the heart of a random orbital machine is the machine's stroke. The stroke is determined
by the offset between the driveshaft axis and the backing axis. A longer offset or
stroke places the backing plate rotational axis farther away from the driveshaft axis.
Multiplying the offset by two produces the stroke diameter. The "stroke" is, therefore,
a term that identifies the diameter of the path the backing plate travels as it orbits
around the driveshaft.
[0009] A majority of random orbital machines are small stroke machines, which mean they
use a stroke length that measures somewhere between approximately 6 mm - 12 mm. A
small stroke machine limits the movement of the pad to a smaller and tighter orbit.
This results in a smoother action. A small stroke machine is also easier to control
because the backing plate orbits around the driveshaft rotational axis in a tighter
path. There are less vibrations and movement making the machine easier to hold due
to the smoother action.
[0010] A large stroke machine delivers increased orbits per minute (OPM) of backing plate
motion using the same rotations per minute (RPM), as the orbit of the backing plate
and the pad around the drive shaft is increased. A large stroke also increases movement
of the pad which helps spread out polishing compounds and treats a larger surface
area. It also accomplishes more cutting action into the paint which allows for scratches
and paint defects to be corrected. Small stroke machines typically only polish the
paint and do not cut into it, and, therefore, are not able to remove surface defects.
[0011] One method of addressing the deficiencies of a small stroke has been to increase
the RPM of the machine. While this increases the rotation of the motor, the machine
stroke stays the same. There are also longevity issues associated with increased RPM
for the motor and increased OPM for the pad. Increasing the RPM puts more strain on
the motor, while increased OPM burns out a pad faster.
[0012] In sum, both long stroke and short stroke machines have their place in the industry.
Therefore, what is needed is a machine that can be adjusted by the user without special
tools or disassembly of the machine. Finally, what is needed is a compact, simple,
and effective method to adjust the stroke of a machine based on the needs of the user.
SUMMARY
[0013] According to the disclosure, an adjustable stroke device for a random orbital machine
comprises a housing having a central axis and a wall that defines a cavity. The housing
includes a drive hub and cover. At least one counterweight is movably disposed at
least partially within the cavity. A mounting assembly is disposed at least partially
within the cavity. The mounting assembly includes a workpiece attachment mechanism.
A stroke adjuster couples the at least one counterweight with the mounting assembly.
The stroke adjuster enables the at least one counterweight and mounting assembly to
move with respect to one another such that a distance between the at least one counterweight
and the mounting assembly may be variable adjusted which, in turn, variable adjust
the stroke radius of the workpiece attachment mechanism with respect to the central
axis of the housing. The stroke adjuster includes an adjuster ring and a cam mechanism.
The adjuster ring engages the cam mechanism to enable the variable adjustment of the
distance. The adjuster ring surrounds the wall of the housing. The adjuster ring is
axially movable and rotatable around the central axis. The counterweight engages the
cam mechanism which moves the counterweight in response to cam movement. The mounting
assembly, including a bearing carriage, engages the cam mechanism. The mounting assembly
moves in response to cam movement. The workpiece attachment mechanism further includes
a spindle coupling with the bearing carriage. A locking mechanism is associated with
the mounting assembly and counter balance to lock the drive in a rotational only position.
At least one projection on the stroke adjuster ring engages at least one cutout on
the cam mechanism to engage the variable adjustment. Preferably the cam mechanism
is a cam plate adjacent a drive hub. The counterweight and mounting assembly are fully
disposed in the cavity.
[0014] According to a second embodiment, a rotating tool comprises a housing and the motor,
the motor includes a drivetrain. An adjustable stroke device is coupled with the drivetrain.
The adjustable stroke device comprises a housing having a central axis and a wall
that defines a cavity. The housing includes a drive hub and cover. At least one counterweight
is movably disposed at least partially within the cavity. A mounting assembly is disposed
at least partially within the cavity. The mounting assembly includes a workpiece attachment
mechanism. A stroke adjuster couples the at least one counterweight with the mounting
assembly. The stroke adjuster enables the at least one counterweight and mounting
assembly to move with respect to one another such that a distance between the at least
one counterweight and the mounting assembly may be variably adjusted which, in turn,
variably adjusts the stroke radius of the workpiece attachment mechanism with respect
to the central axis of the housing. The stroke adjuster includes an adjuster ring
and a cam mechanism. The adjuster ring engages the cam mechanism to enable the variable
adjustment of the distance. The adjuster ring surrounds the wall of the housing. The
adjuster ring is axially movable and rotatable around the central axis. The counterweight
engages the cam mechanism which moves the counterweight in response to cam movement.
The mounting assembly, including a bearing carriage, engages the cam mechanism. The
mounting assembly moves in response to cam movement. The workpiece attachment mechanism
further includes a spindle coupling with the bearing carriage. A locking mechanism
is associated with the mounting assembly and counter balance to lock the drive in
a rotational only position. At least one projection on the stroke adjuster ring engages
at least one cutout on the cam mechanism to engage the variable adjustment. Preferably
the cam mechanism is a cam plate adjacent a drive hub. The counterweight and mounting
assembly are fully disposed in the cavity.
[0015] Further areas of applicability will become apparent from the description provided
herein. The description and specific examples in this summary are intended for purposes
of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0016] The drawings described herein are for illustrative purposes only of selected embodiments
and not all possible implementations, and are not intended to limit the scope of the
present disclosure.
FIG. 1 is a perspective view of a rotating tool according to the disclosure.
FIG. 2 is a perspective view partially in cross-section of the tool of FIG. 1.
FIG. 3 is an exploded view of the adjustable stroke device.
FIG. 4 is a cross-section view of FIG. 1 along line 4-4 thereof.
FIG. 5 is a cross-section view like FIG. 4 of the stroke adjuster.
FIG. 6 is a cross-section view like FIG. 5 after rotation.
FIG. 7 is a cross-section view of the stroke adjuster device.
FIG. 8 is a cross-section view along line 8-8 thereof.
DETAILED DESCRIPTION
[0017] Example embodiments will now be described more fully with reference to the accompanying
drawings.
[0018] Turning to the figures, a tool is illustrated with an adjustable stroke device and
is designated with the reference numeral 10. The tool includes a motor 12, a power
source 14 and a switch 16 to activate and deactivate the power source. The power source
is shown as a cord but could be rechargeable batteries. The motor includes a pinion
18 positioned inside the head housing 26 of the tool. The drivetrain head housing
26 includes a cavity to house a drivetrain 22. The drivetrain 22 includes a bevel
gear 24 meshing with the pinion 18. The bevel gear 24 is coupled with the adjustment
stroke device 30 that is mounted at the bottom of the head housing 26.
[0019] The adjustment stroke device 30 includes a drive hub 34, a workpiece mounting assembly
36, a counterbalance mechanism 38, a stroke adjustment mechanism 40 and a cover 42.
The drive hub 34 and cover 42 form a housing that defines a cavity.
[0020] The drive hub 34 includes a body 44 includes pair of slot 46, cutouts 56, and a pair
of wall wings 48. A driveshaft 50 couples with a boss 52 extending from the body 44.
The driveshaft 50 passes through and is received by a bearing 54 in the drivetrain
head housing 26. Ultimately, the driveshaft 50 is rotatably coupled with the bevel
gear 24 to provide rotation to the drive hub 34.
[0021] A stop pin 28 is biased on the head housing 26. The stop pin 28 engages an aperture
in the bevel gear 24 to prohibit rotation of the drivetrain during changing of the
stroke adjuster device 30. Also, the head housing 26 includes a handle portion 32.
[0022] The wings 48 have a flat wall surface 58 opposing one another. The wall surfaces
58 guide the counterbalance mechanism 38 and workpiece mounting assembly 36 during
movement.
[0023] The stroke adjustment mechanism 40 includes an adjuster cup 64 and a cam plate 66.
The cup 64 is positioned around the drive hub 34 and cover 42 as illustrated in FIG.
1. The cup 64 includes at least one, preferably 4, projections 62 for engaging the
cam plate cutouts 60 and drive hub cutouts 56. The cam plate 66 includes arcuate cam
slots 68. The cup 64 is manually manipulated, and pulled axially downward and rotated
against a force of a spring 70. The spring 70 seats in a spring bearing ring 71. As
this occurs, the stop pin 28 engages the gear aperture stopping rotation of the shaft.
This enables the user to move the adjustable stroke mechanism 40 between operating
positions. The cam plate 66 is nested on the drive hub body 44 along boss 52. This
enables rotation of the stroke adjustment mechanism 40 and the drive hub 34 as explained
later.
[0024] The workpiece mounting assembly 36 includes a bearing carriage 72, a U-shaped body
portion 74 and a weight 75. The bearing carriage 72 receives bearings 76 and a spindle
78. The spindle 78 extends through the bearings and is retained on the U-shaped body
portion 74. The spindle 78 has an external portion 80 that includes a threaded bore
81 to receive a backing plate 82 and fastener 83. The workpiece mounting assembly
36 also includes a locking gear 86. The locking gear 86 engages teeth 94 on the counterbalance
mechanism 38 to lock the workpiece mounting assembly 36 in a pure rotation position.
[0025] The U-shaped body portion 74 includes a pin 88. The pin 88 is received in one of
the cam slots 68 and one of the drive hub slots 46. The pin 88 is also fixed in the
weight 75 on the side of the body 44. Thus, the workpiece mounting assembly 34 is
moved with respect to the counterbalance mechanism 38 upon rotation of the stroke
adjustment mechanism 40.
[0026] The counterbalance mechanism 38 includes a body 90 with a step portion 92. The body
90 has an overall U-shape with the step 92 extending from the web. The inner surface
of the body 90 includes a plurality of teeth 94. The teeth 94 engage with the locking
gear 86 as mentioned above to position the adjustable stroke device 30 in a purely
rotational position. The step 92 include a pin 98 that is positioned in the other
of the cam slots 68 and drive hub slots 46. The pin 98 is positioned in the slots
68, 46 opposite of the U-shaped workpiece mounting assembly pin 88. Thus, as the stroke
adjuster cup 64 is rotated, the counterbalance mechanism 38 and the workpiece mounting
assembly 36 are moved away or towards one another. In the purely rotation position,
the lock gear 86 engages the teeth 94.
[0027] The cylindrical cover 42 includes a base 100 that covers the bottom of the stroke
adjuster 30. The spindle portion 80 extends through the cover base oval opening 102
to enable connection with the backing plate 84. The cylindrical cover wall 103 provides
a substantially continuous cylindrical housing. The cover 42 is secured to the drive
hub 34 via screws 104. Thus, the counterbalance mechanism 38 as well as the workpiece
mounting assembly 36 are positioned inside of the cover 42 and drive hub 34 housing.
[0028] In operation, the stop pin 28 engage the bevel gear aperture and the stroke adjustment
mechanism adjuster cup 64 is pulled toward the drive hub 34 and rotated. As this occurs,
the projections 62, biased by spring 70, insert into the cam plate 66, cutouts 60
and the drive hub cut out 56. The adjuster cup 64 continues to turn or rotate until
the next position is aligned, 8 mm stroke. As this occurs, the force on the adjustable
stroke cup 64 is released and the stroke device 30 is locked into a position. The
positions move from a purely rotational position to a dual action position of an 8
and 15 mm stroke.
[0029] As the cup 64 is rotated, the pins 88, 98 in the slots 46, 68 are moved. As this
occurs, the workpiece mounting assembly 36 and counterbalance mechanism 38 are moved
either toward one another or away from one another. In a rotary only position, the
workpiece mounting assembly locking gear 86 engages the teeth 94 of the counterbalance
mechanism 38. This provides rotational only movement. As the workpiece mounting assembly
36 and counterbalance 38 mechanisms are moved away from one another, the workpiece
mounting assembly 36 freely rotates in the counterweight 38 and housing providing
the dual action rotary and orbital movement.
[0030] Accordingly, the activation switch 16 energizes the motor which rotates the spindle
50 which, in turn, rotates the drive hub 34. This enables the backing plate 84 to
be rotated with the counterbalance mechanism 38 balancing the rotational imbalance
due to the spindle 78 being offset from the central axis of the spindle 50. Thus,
the spindle 78 rotates the workpiece backing plate 84 at a stroke distance away from
the central axis.
[0031] The foregoing description of the embodiments has been provided for purposes of illustration
and description. It is not intended to be exhaustive or to limit the disclosure. Individual
elements or features of a particular embodiment are generally not limited to that
particular embodiment, but, where applicable, are interchangeable and can be used
in a selected embodiment, even if not specifically shown or described. The same may
also be varied in many ways. Such variations are not to be regarded as a departure
from the disclosure, and all such modifications are intended to be included within
the scope of the disclosure.
1. An adjustable stroke device for a random orbital machine comprising:
a housing having a central axis and a wall defining a cavity;
at least one counterweight movably disposed at least partially within the cavity;
a mounting assembly disposed at least partially within the cavity, the mounting assembly
including a workpiece attachment mechanism; and
a stroke adjuster coupling the at least one counterweight with the mounting assembly,
the stroke adjuster enabling the at least one counterweight and mounting assembly
to move with respect to one another such that a distance between the at least one
counterweight and the mounting assembly may be variably adjusted which, in turn, variably
adjusts a stroke radius of the workpiece attachment mechanism with respect to the
central axis of the housing, the stroke adjuster including an adjuster ring and a
cam mechanism, the adjuster ring engaging the cam mechanism for enabling the variable
adjustment of the stroke distance.
2. The adjustable stroke device of Claim 1, wherein the adjuster ring surrounding the
wall of the housing, the adjuster ring is axially movable and rotatable around the
central axis.
3. The adjustable stroke device of Claim 1, wherein the counterweight engages the cam
mechanism for moving the counterweight in response to cam movement.
4. The adjustable stroke device of Claim 2, wherein the mounting assembly, including
a bearing carriage, engaging the cam mechanism for moving the mounting assembly in
response to cam movement.
5. The adjustable stroke device of Claim 1, wherein the workpiece attachment mechanism
further comprises a spindle, the spindle coupling with a bearing carriage.
6. The adjustable stroke device of Claim 2, further comprising a locking mechanism associated
with the mounting assembly and counterbalance to lock the drive in a rotation only
position.
7. The adjustable stroke device of Claim 1, further comprising at least one projection
on the adjuster ring for engaging at least one cut out on the cam mechanism for enabling
the variable adjustment.
8. The adjustable stroke device of Claim 1, where the cam mechanism further comprising
a cam plate adjacent to a drive hub.
9. The adjustable stroke device of Claim 1, wherein the housing includes a drive hub
and a cover.
10. The adjustable stroke device of Claim 1, wherein the counterweight and mounting assembly
are fully disposed in the cavity.
11. A rotating tool comprising:
a housing and a motor, the motor including a drive train;
an adjustable stroke device coupled with the drivetrain, the adjustable stroke device
comprising:
a housing having a central axis and a wall defining a cavity;
at least one counterweight movably disposed at least partially within the cavity;
a mounting assembly disposed at least partially within the cavity, the mounting assembly
including a workpiece attachment mechanism; and
a stroke adjuster coupling the at least one counterweight with the mounting assembly,
the stroke adjuster enabling the at least one counterweight and mounting assembly
to move with respect to one another such that a distance between the at least one
counterweight and the mounting assembly may be variably adjusted which, in turn, variably
adjust a stroke radius of the workpiece attachment mechanism with respect to the central
axis of the housing, the stroke adjuster including an adjuster ring and a cam mechanism,
the adjuster ring engaging the cam mechanism for enabling the variable adjustment
of the distance.
12. The rotating tool of Claim 11, wherein the adjuster ring surrounding the wall of the
housing, the adjuster ring is axially movable rotatable around the central axis.
13. The rotating tool of Claim 11, wherein the counterweight engages the cam mechanism
for moving the counterweight in response to cam movement.
14. The rotating tool of Claim 12, wherein the mounting assembly, including a bearing
carriage, engaging the cam mechanism for moving the mounting assembly in response
to cam movement.
15. The rotating tool of Claim 11, wherein the workpiece attachment mechanism further
comprises a spindle, the spindle coupling with a bearing carriage.
16. The rotating tool of Claim 12 further comprising a locking mechanism associated with
the mounting assembly and counterbalance to lock the drive in a rotation only position.
17. The rotating tool of Claim 11, further comprising at least one projection on the adjuster
ring for engaging at least one cutout on the cam mechanism for enabling the variable
adjustment.
18. The rotating tool of Claim 11, wherein the cam mechanism further comprising a cam
plate adjacent a drive hub.
19. The rotating tool of Claim 11, wherein the housing includes a drive hub and a cover.
20. The rotating tool of Claim 11, wherein the counterweight and mounting assembly are
fully disposed in the cavity.