Patent Publication Number: US-2021187695-A1

Title: Adjustable Stroke Mechanism For Random Orbital Machine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. provisional application No. 62/249,521, filed on Nov. 2, 2015, and U.S. provisional application No. 62/340,335, filed on May 23, 2016, the entire contents of which are both hereby expressly incorporated by reference into this application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method and apparatus for adjusting the stroke on a random orbital machine, such as, but not limited to, polishing machines and sanding machines. This adjustment ability allows a user to define the stroke of the random orbital machine and adjust it between a maximum definitive stroke setting and minimum zero orbit setting. 
     2. Discussion of the Related Art 
     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. 
     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. 
     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. 
     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. 
     At the heart of a random orbital machine is the machine&#39;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. 
     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. 
     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. 
     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. 
     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 OF THE INVENTION 
     A random orbital machine that includes an adjustable stroke mechanism defined by the user with a housing configured to mount the adjustable stroke mechanism to the random orbital machine. 
     In accordance with a first embodiment of the invention, a random orbital machine includes an adjustable stroke mechanism, a gear case housing configured to mount the adjustable stroke mechanism, and a shroud is attached to the gear case and configured to enclose the adjustable stroke mechanism within the gear case. In order to adjust the stroke, a first gear with a first diameter and a counterweight attachment point is spaced apart from a central rotational axis of the first gear, a second gear with a second diameter equal to the first diameter and a backing plate attachment point is spaced apart from a central rotational axis of the second gear, and an idler gear is connected to the gear case engaging both the first gear and the second gear such that rotation of any of the first gear, second gear, and idler gear causes rotation in each one of the first, second, and idler gears. The random orbital machine further includes an adjustment bar with a fixed rotational axis attached to the gear case and a slot extending along a length of the adjustment bar. A counterweight is attached to the attachment point of the first gear through the groove in the adjustment bar and spaced from the rotational axis of the adjustment bar such that rotation of the first gear slides the counterweight attachment point along the groove. Further, a backing plate mount is attached to the attachment point of the second gear through the groove of the adjustment bar opposite the counterweight and spaced from the rotational axis of the adjustment bar such that rotation of the second gear slides the backing plate attachment point along the groove thus adjusting the stroke of the random orbital machine. A key on the underside of the counterweight fits within a groove in the adjustment bar and automatically aligns and pivots the counterweight as the first gear is rotated. 
     According to another embodiment of the invention, an adjustable stroke mechanism includes a gear case attached to a random orbital machine, an adjustment bar with a fixed rotational axis attached within the gear case, and a slot extending along a length of the adjustment bar. The adjustable stroke mechanism further includes a counterweight with an attachment point slidably held within the groove in the adjustment bar and spaced from the rotational axis of the adjustment bar and a backing plate mount with an attachment point slidably held within the groove in the adjustment bar opposite the counterweight and spaced from the rotational axis of the adjustment bar, wherein movement of the backing plate mount along the groove of the adjustment bar causes equal and opposite movement of the counterweight along the groove of the adjustment bar. 
     In accordance with yet another embodiment of the invention, a method of adjusting a stroke of a random orbital machine includes rotating a first gear about a rotational axis within a gear case of the random orbital machine, rotating a counter weight about the rotational axis of the first gear, and sliding the counterweight along a groove along an adjustment bar as the first gear is rotated. The method further includes rotating the adjustment bar as the first gear is rotated about a rotational axis of the adjustment bar, rotating an idler gear meshed with the first gear as the first gear is rotated, rotating a second gear meshed with the idler gear about a rotational axis as the first gear is rotated, rotating a backing plate mount about the rotational axis of the second gear as the first gear is rotated, and sliding the backing plate mount along the groove along the adjustment bar as the second gear is rotated such that, as the backing plate mount moves along the groove in the adjustment bar, the counterweight moves along the adjustment bar in an equal and opposite direction. 
     According to yet another embodiment of the invention, an adjustable stroke mechanism includes a first rack gear with a first end and a second end opposite the first end, a second rack gear with a first end and a second end opposite the first end, and at least one pinion gear meshed with and between the first rack gear and the second rack gear. In addition, the adjustable stroke mechanism includes a counterweight attached to a first end of the first rack gear and a backing plate mount attached to the second end of the second rack gear, wherein rotation of the pinion gear moves the each one of the counterweight and the backing plate away or toward one another depending on the rotational direction of the pinion gear, thus adjusting the stroke and providing a proper counterweight balance. 
     In accordance with yet another embodiment of the invention, an adjustable stroke mechanism includes a housing having a circular wall enclosing a cavity, wherein the wall includes a plurality of apertures, and an adjuster ring surrounding an outer surface of the wall of the housing, the adjuster ring having a first set of gear teeth along a first portion of an inner surface of the adjuster ring and a second set of gear teeth along a second portion of the inner surface of the adjuster ring. Additionally, the adjustable stroke mechanism includes a counterweight disposed within the housing, the counterweight having an orifice formed therein and a set of gear teeth along an exterior surface thereof, and at least one counterweight gear disposed between the counterweight and the adjuster ring and within one of the plurality of apertures in the wall of the housing, the at least one counterweight gear configured to mesh with the first set of gear teeth of the adjuster ring and the set of gear teeth of the counterweight so that rotation of the adjuster ring causes movement of the counterweight. Further, the adjustable stroke mechanism includes a bearing carriage disposed within the housing, the bearing carriage having an orifice formed therein and a set of gear teeth along an exterior surface thereof, and at least one bearing carriage gear disposed between the bearing carriage and the adjuster ring and within another of the plurality of apertures in the wall of the housing, the at least one bearing carriage gear configured to mesh with the second set of gear teeth of the adjuster ring and the set of gear teeth of the bearing carriage so that rotation of the adjuster ring causes movement of the bearing cage. 
     In accordance with yet another embodiment of the invention, a method of adjusting a stroke of a random orbital machine includes coupling an adjustable stroke mechanism to a random orbital machine. The adjustable stroke mechanism includes a housing with a circular wall enclosing a cavity, an adjuster ring surrounding an outer surface of the circular wall, a counterweight disposed within the cavity, a counterweight gear disposed within the cavity, a bearing carriage disposed within the cavity, a bearing carriage gear disposed within the cavity, and a bearing axle coupled to the bearing carriage. The method further includes rotating the adjuster ring. The adjuster ring has a first set of gear teeth along a first portion of an inner surface of the adjuster ring and a second set of gear teeth along a second portion of the inner surface of the adjuster ring. Rotating the adjuster ring causes the counterweight gear to rotate and the counterweight to move. The counterweight gear is configured to mesh with the first set of gear teeth of the adjuster ring. The counterweight has a set of gear teeth configured to mesh with the counterweight gear. Rotating the adjuster ring causes the bearing carriage gear to rotate and the bearing carriage to move. The bearing carriage gear is configured to mesh with the second set of gear teeth of the adjuster ring. The bearing carriage has a set of gear teeth configured to mesh with the bearing carriage gear. 
     In accordance with yet another embodiment of the invention, an adjustable stroke mechanism for a random orbital machine includes a first gear, a counterweight coupled to the first gear, a second gear, and a backing plate mount in connection with second gear. The backing plate is configured to move in response to movement of the second gear. Further, rotation of one of the first gear and the second gear causes rotation of the other of the first gear and the second gear. 
     In addition, the adjustable stroke mechanism may include a bearing carriage including a plurality of gear teeth configured to interfit with a plurality of gear teeth of the second gear. The counterweight includes a plurality of gear teeth configured to interfit with a plurality of gear teeth of the first gear. A bearing axle is disposed within an orifice of the bearing carriage, the bearing axle includes the backing plate mount. The first gear, the counterweight, the second gear, and the bearing carriage are disposed within a housing. 
     Further, the adjustable stroke mechanism may include an adjuster ring surrounding an outer wall of the housing. The adjuster ring includes a first set of gear teeth along a first portion of an inner surface of the adjuster ring and a second set of gear teeth along a second portion of the inner surface of the adjuster ring. The first set of gear teeth are configured to interfit with the plurality of gear teeth of the counterweight. The second set of gear teeth configured to interfit with the plurality of gear teeth of the bearing carriage. 
     The adjuster ring is rotatable between a plurality of predetermined positions. Rotating the adjuster ring causes the first gear to rotate and the second gear to rotate. Rotating the first gear causes the counterweight to move. Rotating the second gear causes the bearing carriage and bearing axle to move. 
     Additionally, the backing plate mount may include at least one of an inner thread and an outer thread configured to couple to adjustable stroke mechanism to a tool. 
     These and other aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A clear conception of the advantages and features constituting the present invention, and of the construction and operation of typical mechanisms provided with the present invention, will become more readily apparent by referring to the exemplary, and therefore non-limiting, embodiments illustrated in the drawings accompanying and forming a part of this specification, wherein like reference numerals designate the same elements in the several views, and in which: 
         FIG. 1  is a raised perspective view of a known, prior art, random orbital machine; 
         FIG. 2  is a raised perspective view of a first embodiment of an adjustable stroke mechanism for a random orbital machine showing an adjustable counterweight and adjustable backing plate mount; 
         FIG. 3  is a top view of the adjustable stroke mechanism of  FIG. 2  in a fully extended stroke position and with the backing plate mount removed; 
         FIG. 4  is a bottom view of the counterweight of  FIG. 2 ; 
         FIG. 5  is a top view of the adjustable stroke mechanism of  FIG. 2  in a fully retracted stroke position and with the backing plate mount removed; 
         FIG. 6  is a top view of a second embodiment of an adjustable stroke mechanism for a random orbital machine shown in a fully extended stroke position; 
         FIG. 7  is a top view of the adjustable stroke mechanism of  FIG. 6  in a fully retracted stroke position. 
         FIG. 8  is an exploded perspective view of a third embodiment of an adjustable stroke mechanism for a random orbital machine, according to the present invention; 
         FIG. 9  is a perspective view of the adjustable stroke mechanism of a random orbital machine of  FIG. 8 ; 
         FIG. 10  is a side sectional view taken along line  10 - 10  of the adjustable stroke mechanism of a random orbital machine of  FIG. 9 ; 
         FIG. 1I  is a top view of the adjustable stroke mechanism of  FIG. 9  in a first position; 
         FIG. 12  is a top view of the adjustable stroke mechanism of  FIG. 9  in a second position; 
         FIG. 13  is a top view of the adjustable stroke mechanism of  FIG. 9  in a third position; 
         FIG. 14  is a top view of the adjustable stroke mechanism of  FIG. 9  in a fourth position; 
         FIG. 15  is a top view of the adjustable stroke mechanism of  FIG. 9  in a fifth position; 
         FIG. 16  is a bottom perspective view of the adjustable stroke mechanism of  FIG. 9  in a first position with the locking plate in a locked position; 
         FIG. 17  is a bottom perspective view of the adjustable stroke mechanism of  FIG. 9  in a first position with a locking plate in an unlocked position; 
         FIG. 18  is a bottom perspective view of the adjustable stroke mechanism of  FIG. 9  in a second position; 
         FIG. 19  is a bottom perspective view of the adjustable stroke mechanism of  FIG. 9  in a third position; 
         FIG. 20  is a bottom perspective view of the adjustable stroke mechanism of  FIG. 9  in a fourth position; 
         FIG. 21  is a bottom perspective view of the adjustable stroke mechanism of  FIG. 9  in a fifth position; 
         FIG. 22  is a side view of an adjustable stroke mechanism, according to an alternative embodiment of the invention; 
         FIG. 23  is a cross-sectional view of a bearing axle of the adjustable stroke mechanism of  FIG. 22  taken along line  23 - 23 ; and 
         FIG. 24  is a top perspective view of an adjustable stroke mechanism, according to an alternative embodiment of the invention. 
     
    
    
     In describing the preferred embodiments of the invention which are illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments described in detail in the following description. 
       FIG. 1  depicts a known random orbital machine  10  with a conventional, fixed stroke. The random orbital machine  10  is operated by plugging in the power delivery device  9 , which, in this case, is an electrical cord. The switch  7  may be depressed, which energizes the motor  8  that causes a driveshaft (not pictured) to rotate. A gear case  21  attaches to a shroud  12  and contains a counterweight  14  and backing plate mount  17  assembly. 
     The driveshaft has a rotational axis  20  which is offset from the backing plate axis  18 . The backing plate mount  17  orbits about the driveshaft axis once for every revolution of the driveshaft. This is due to the offset which is measured by the stroke radius  22 . The stroke diameter  24  is calculated by multiplying the stroke radius  22  by two, and this number is commonly used and referred to as the stroke of the random orbital machine  10 . A backing plate bearing  16  allows the backing plate mount  17  to freely spin at random during the orbital action. In order to prevent substantial vibrations due to the stroke radius  22 , a counterweight  14  is provided. The counterweight  14  is calculated to have a mass and center of mass that is offset from the driveshaft axis, which may be aligned or offset from the rotational axis  20  of the adjustment bar  34 , such that it counteracts the vibrations caused due to the orbiting backing plate mount  17  and stroke radius  22 . Each one of the rotating components of the random orbital machine  10  is located within a shroud  12  that prevents foreign bodies or the user&#39;s finger(s) from damage during use. 
     Moving on to  FIG. 2 , a first embodiment of an adjustable stroke mechanism  26  is shown. The adjustable stroke mechanism  26  utilizes a series of gears to allow the backing plate mount  54  and counterweight  28  to automatically move toward or away from one another as any one of the gears is rotated. These synched movements of the backing plate mount  54  and the counterweight  28  allow the offset, or stroke, of a random orbital machine  10  to be adjusted while keeping vibrations in check. The offset may be adjusted between a maximum and minimum setting, or be adjustable by choosing a series of pre-selected settings. 
     A shroud will enclose the adjustable stroke mechanism  26  and is represented by a proposed shroud perimeter  48 . The shroud would function much as the shroud  12  shown in  FIG. 1  and will enclose the components of the adjustable stroke mechanism  26 . The proposed shroud curvature  52  may also be matched to the counterweight curvature  46  such that the counterweight  28  will not intersect the proposed shroud perimeter  48  during operation. 
     The entire contents within the proposed shroud perimeter  48  rotate and are all intended to be placed within the shroud  12  much as shown in  FIG. 1 . For this reason, special care must be taken to ensure the counterweight  28  is always oriented in the proper direction and that its center of mass is always properly spaced from the backing plate axis  32  as the stroke is adjusted. 
     In order to adjust the stroke on the adjustable stroke mechanism  26 , any one of a first gear  40 , second gear  42 , or idler gear  44  may be rotated. The first gear  40  meshes with the idler gear  44  and the idler gear  44  meshes with the second gear  42 . The first gear  40  rotates about a first gear rotational axis  43  (at a central point of the first gear  40 , which is obstructed from view) and the second gear  42  rotates about a second gear rotational axis  41 . This rotation causes a subsequent rotation of any one of the gears, which causes all three gears to rotate. This rotational motion of the first gear  40  and second gear  42  is transferred to a movement of the counterweight  28  and backing plate mount  54 , respectively. The rotational motion of the gears is transferred by not only the idler gear  44 , but also by an adjustment bar  34 . The adjustment bar  34  includes a groove  36  along its length. The backing plate mount  54  attaches to the second gear  42  through the groove  36  in the adjustment bar  34 . A key  35 , seen in  FIG. 4 , on the back of the counterweight  28  rides in the groove  36  of the adjustment bar  34  and ensures that the counterweight  28  is always oriented in the right direction to eliminate vibrations. The counterweight attachment point  38  passes through a bore  37  in the key  35  and allows the counterweight  28  to freely pivot about the counterweight attachment point  38 . 
       FIG. 3  also shows a bearing  30  which allows the backing plate mount  54  to spin freely about a backing plate axis  32 . When a backing plate is secured to the backing plate mount, a pad may be attached to the backing plate. The pad will then spin freely and randomly about the backing plate axis  32 . 
     As the counterweight attachment point  38  is not in the center of the first gear  40 , the counterweight attachment point  38  orbits around the center of the first gear  40  as the first gear  40  is rotated. This orbital motion pushes on the adjustment bar  34  and causes the backing plate mount  54  to also orbit around the center of the second gear  42 . This happens because the backing plate mount  54  is fastened to the second gear  42 , as shown in  FIG. 3 . The backing plate attachment point  33  passes through the groove  36  and pivots the adjustment bar  34  as the second gear  42  rotates. This motion causes the counterweight  28  to always remain aligned, as it pivots on the counterweight attachment point  38 . The key  35 , as shown in  FIG. 4 , rides in the groove  36 . As a result, the counterweight  28  balances out the adjustable stroke mechanism  26  regardless of the stroke setting. 
       FIG. 3  shows a fully extended stroke  56 . The backing plate attachment point  33  is adjusted such that the stroke radius  22  is fully extended. In this position, the backing plate attachment point  33  is fully extended to the end of the groove  36  in the adjustment bar  34 . The adjustment bar attachment point  50  holds the adjustment bar  34  to the adjustable stroke mechanism  26 , spaced above the first gear  40 , second gear  42 , and idler gear  44 . 
     The counterweight  28  is also fully extended, and the key  35  is at the end of the groove  36  on the opposite side of the backing plate attachment point  33 . The shape of the key  35  fits snugly in the groove  36  and maintains any point on the counterweight  28  facing the same point on the backing plate attachment point  33 . 
       FIG. 5 , for example, shows a fully retracted stroke  58 . The stroke radius  23  in  FIG. 5  is less than the stroke radius  22  in  FIG. 3 . This is due to rotation of any one of the first gear  40 , second gear  42 , and idler gear  44 . The first gear  40  and the second gear  42  are preferably the same diameter. The backing plate attachment point  33  is also spaced away from the center of the second gear  42  the same distance as the counterweight attachment point  38  is spaced from the center for the first gear  40 . This ensures that the counterweight  28  moves at the same rate as the backing plate mount  54  as any of the gears are rotated. This maintains proper balance despite changing the stroke length. 
     Transitioning now to  FIG. 6 , a second embodiment of an adjustable stroke mechanism  60  is shown. The adjustable stroke mechanism  60  is represented within the perimeter of a shroud  48 , similar to the known random orbital machine  10  in  FIG. 1 . The proposed shroud perimeter  48  also has a proposed shroud curvature  52  that houses the entire adjustable stroke mechanism  60 . The entire adjustable stroke mechanism  60  rotates within the proposed shroud perimeter  48  when the random orbital machine  10  is activated by depressing the switch  7 . 
     A fully extended stroke  74  is shown in  FIG. 6 . The stroke radius  22  is shown by the offset of the backing plate mount  54  to the rotational axis  20  of the backing plate mount  54 . The counterweight  28  balances out the backing plate mount  54  such that minimal vibrations are experienced when the adjustable stroke mechanism  60  is activated. 
     The stroke radius  22  is adjusted by movement of a first rack gear  66 , a second rack gear  68 , a first pinion gear  62 , and a second pinion gear  64 . It is envisioned that a single pinion gear may also be used to adjust the stroke radius  22  as well. Both the first rack gear  66  and the second rack gear  68  have teeth along the length of the respective gears. The first pinion gear  62  and the second pinion gear  64  have corresponding and meshed teeth. As a result, when either one of the first pinion gears  62  and second pinion gears  64  are rotated, the first rack gear  66  and the second rack gear  68  also move in opposing directions. This motion is exemplified, for example, in the illustration  70 . In the illustration  70 , it is shown that as the second rack gear  68  moves to the left, the first pinion gear  62  rotates clockwise. Moving the first pinion gear  62  counter clockwise would cause the second rack gear  68  to move to the right. 
     As the counterweight  28  is secured to the first rack gear by a counterweight attachment point  38 , and the backing plate mount  54  is secured to the second rack gear  68  with a backing plate attachment point  33 , the stroke radius  22  may be easily adjusted. Also, as the stroke radius  22  is adjusted, the counterweight  28  is automatically kept at the desired distance from the rotational axis  20  to balance out the orbital motion of the backing plate mount  54 . 
       FIG. 7  shows the fully retracted stroke  72 . When the stroke is fully retracted, the stroke radius  23  is seen as shorter, as the offset between the backing plate axis  32  and the rotational axis  20  of the adjustable stroke mechanism  60  is lessened. Just as with respect to  FIG. 2 , the embodiment shown in  FIG. 6  and  FIG. 7  also has a bearing  30  to which the backing plate mount  54  is attached. The bearing  30  allows the backing plate mount to freely spin at random about the backing plate axis  32  as it orbits the rotational axis  20 . Either one of the embodiments discussed herein also allows the stroke to be adjusted anywhere between the fully retracted  72  and fully extended strokes  74 . 
     Referring now to  FIG. 8 , a third embodiment of an adjustable stroke mechanism  100  is shown in an exploded perspective view in order to show the various components within the adjustable stroke mechanism  100 . The adjustable stroke mechanism  100  includes a housing  102  having a wall  104  surrounding a cavity  106 . As shown in  FIG. 8 , the wall  104  is depicted as circular in shape; however, the wall  104  could be in the form of any number of shapes. In addition, the housing  102  includes a top plate  108  oriented perpendicular to the wall  104 , which provides an upper limit to the cavity  106 . The housing  102  also includes a housing cover  110  oriented perpendicular to the wall  104  and opposite the top plate  108 , which provides a lower limit to the cavity  106 . The wall  104  of the housing  102  has a plurality of apertures  112  formed therein. While  FIG. 8  shows two (2) apertures  112  formed in the wall  104 , it is contemplated that either more or less than two (2) apertures  112  may be formed in the wall  104 . 
     An adjuster ring  114  surrounds an outer surface  116  the wall  104  of the housing  102 . An inner surface  118  of the adjuster ring  114  includes a first portion  120  and a second portion  122 . A first set of gear teeth  124  is positioned along the first portion  120  of the inner surface  118  of the adjuster ring  114 . Similarly, a second set of gear teeth  126  is positioned along the second portion  122  of the inner surface  118  of the adjuster ring  114 . As shown in  FIG. 8 , the adjuster ring  114  and the housing  102  are aligned so that first and second sets of gear teeth  124 ,  126  line up with the plurality of apertures  112 . 
     In one embodiment of the invention, the first and second sets of gear teeth  124 ,  126  are formed in the inner surface  118  of the adjuster ring  114 ; however, it is also contemplated that the first and second sets of gear teeth  124 ,  126  may be a separate piece attached to the inner surface  118  of the adjuster ring  114 . Further, while  FIG. 8  depicts the first and second portions  120 ,  122  as being only segments of the entire inner surface  118  of the adjuster ring  114 , it is also contemplated that the first and second portions  120 ,  122  may cover the entire inner surface  118  of the adjuster ring  114 . In turn, alternative embodiments of the invention may include first and second sets of gear teeth  124 ,  126  covering the entirety of the inner surface  118  of the adjuster ring  114 . 
     As shown in  FIG. 8 , various additional components are placed with the cavity  106  of the housing  102 . A counterweight  128  is disposed within the cavity  106  of the housing  102 . The counterweight  128  includes a set of gear teeth  130  formed on an outer surface  132  of the counterweight  128 . A counterweight drive gear  134  is placed between the counterweight  128  and the inner surface  118  of the adjuster ring  114 . In particular, the counterweight drive gear  134  meshes with the first set of gear teeth  124  of the adjuster ring  114  and the set of gear teeth  130  of the counterweight  128 . In addition, the counterweight drive gear  134  is configured to sit within one of the plurality of apertures  112  in the wall  104  of the housing  102 . As such, rotation of the adjuster ring  114  results in movement of the counterweight  128  by way of rotation of the counterweight drive gear  134 . 
     A bearing carriage  136  is also disposed within the cavity  106  of the housing  102 . Similar to the counterweight  128 , the bearing carriage  136  includes a set of gear teeth  138  formed on an outer surface  140  thereof. A bearing carriage drive gear  142  is placed between the bearing carriage  136  and the inner surface  118  of the adjuster ring  114 . That is, the bearing carriage drive gear  142  meshes with the second set of gear teeth  126  of the adjuster ring  114  and the set of gear teeth  138  of the bearing carriage  136 . Further, the bearing carriage drive gear  142  is configured to sit within another of the apertures  112  formed in the wall  104  of the housing  102 . As a result, rotation of the adjuster ring  114  also results in movement of the bearing carriage  136  by way of rotation of the bearing carriage drive gear  142 . 
     While  FIG. 8  depicts the counterweight drive gear  134  as a single gear, it is contemplated that the counterweight drive gear  134  may be a plurality of gears configured to change the gear ratio between rotation of the adjuster ring  114  and movement of the counterweight  128 . Likewise, in alternative embodiments of the invention, the bearing carriage drive gear  142  may be a plurality of gears configured to change the gear ratio between rotation of the adjuster ring  114  and movement of the bearing carriage  136 . 
     The counterweight  128  and the bearing carriage  136  may also include a respective orifice  144 ,  146  formed therein. In this instance, a bearing axle  148  extends through both the orifice  144  of the counterweight  128  and the orifice  146  of the bearing carriage  136 . Further, the bearing axle  148  is surrounded by at least one bearing  150 , which is disposed within the orifice  146  of the bearing carriage  136 . The bearing axle  148  also includes a backing plate mount  152 , which extends out of the cavity  106  through an orifice  154  formed in the housing cover  110 . The backing plate mount  152  is configured in such a way as to allow attachment to a tool, such as, but not limited to, a buffing pad. 
     During operation of the adjuster ring  114 , the bearing axle  148  moves with the bearing carriage  136 . As such, the orifice  144  formed in the counterweight  128  is configured to allow the bearing axle  148  to move with the bearing carriage  136 , as the counterweight  128  itself moves in a different direction. 
     In certain embodiments of the invention, the adjustable stroke mechanism  100  may include a locking plate  156 . The locking plate  156  may be secured to an outer surface  158  of the housing cover  110  via a plurality of fasteners  160 , such as, but not limited to, screws. While  FIG. 8  depicts the use of four (4) fasteners  160 , one skilled in the art would readily recognize that more or less than four (4) fasteners  160  may be used to secure the locking plate  156  to the housing cover  110 . The locking plate  156  has an orifice  162  formed therein, which is configured to have the backing plate mount  152  disposed within the orifice  162 . The locking plate  156  is configured to be transitionable between an unlocked position  192  and a locked position  191 . In the unlocked position  192 , the adjuster ring  114  is able to be rotated, and, therefore, the bearing axle  148  is able to be moved between a number of predetermined positions to adjust the stroke. In the locked position  191 , a notch  164  in the orifice  162  engages the backing plate mount  152 , which prevents movement of the backing plate mount  152 . In turn, this prevents movement of the bearing axle  148 , which prevents movement of the bearing carriage  136 , which, in turn, prevents movement of the adjuster ring  114 . 
       FIG. 9  illustrates a perspective view of the adjustable stroke mechanism  100  completely assembled. According to an embodiment of the invention, a mount  166  is formed on the outer surface  168  of the top plate  108  of the housing  102 . In particular, the mount  166  is configured to interact with a random orbital machine, in order to attach the adjustable stroke mechanism  100  to the random orbital machine. In one embodiment of the invention, the mechanism  100  is housed within a shroud of the random orbital machine, similar to the shroud  12  shown in  FIG. 1 . 
     In alternative embodiments of the invention, the shroud may include a plurality of lights, such as LEDs, to illuminate the working surface for a user. In addition, the random orbital machine may also include a temperature sensor, such as an infrared temperature sensor, and/or a gloss meter in order to track the temperature and/or the reflection gloss of the working surface. It is contemplated that the addition of a plurality of lights and a temperature sensor such as described above can be included in any of the embodiments of the invention. 
       FIG. 9  further shows markings  170  indicating the predetermined rotation locations of the adjuster ring  114 . In one embodiment of the invention, the markings  170  correspond to indentions  172  along the circumference of the top plate  108  of the housing  102 . Further, the adjuster ring  114  includes a detent  174  which interacts with a respective one of the indentations  172  as the adjuster ring  114  is rotated between predetermined positions. As a result, a user is given feedback regarding positioning of the stroke mechanism  100  in a predetermined position. This feedback may be tactile, audible, or both as a result of the detent  174  interacting with one of the indentations  172 . 
     Next,  FIG. 10  illustrates a cross-sectional view of  FIG. 9  taken along line  10 - 10 . This view illustrates the relationship of parts within the cavity  106 , as described above. In addition, the housing  102  and the housing cover  110  are coupled to each other by a plurality of fasteners  176 , such as but not limited to the screws shown in the figures. In addition, fasteners  176  provide a pivot axle for certain components  128 ,  134 ,  136 ,  142  of the stroke mechanism  100  and help maintain the alignment of these components  128 ,  134 ,  136 ,  142 . 
     For example, a first fastener  178  of the plurality of fasteners  176  acts as a pivot point for the bearing carriage  136  and an axis of rotation for the counterweight drive gear  134 . Meanwhile, a second fastener  180  of the plurality of fasteners  176  acts as a pivot point for the counterweight  128  and an axis of rotation for the bearing carriage drive gear  142 . In alternative embodiments, it is contemplated that a separate fastener may be used for each pivot point and axis of rotation. 
     As shown in  FIG. 10 , an inner thread  165  may be disposed within the mount  166 , in order to assist with coupling the adjustable stroke mechanism  100  to the random orbital machine. However, it is contemplated that other coupling means may be used in place of the inner thread  165 . Additionally,  FIG. 10  shows an inner thread  151  disposed within the backing plate mount  152 , in order to assist with coupling the adjustable stroke mechanism  100  to a tool. It is also contemplated that other coupling means may be used in place of the inner thread  151 . 
       FIGS. 11-15  show a top view of the adjustable stroke mechanism  100  in a plurality of predetermined locations. The combination of figures illustrates the movement of the counterweight  128  and the movement of the bearing carriage  136  and bearing axle  148  as the adjuster ring  114  is rotated, resulting in a change in stroke. As seen in  FIG. 11 , the detent  174  is engaged in a first indentation  182  of the plurality of indentations  172  to signify that the adjuster ring  114  is in a first position.  FIG. 12  shows the detent  174  engaged in a second indentation  184  of the plurality of indentations  172  to signify that the adjuster ring  114  is in a second position.  FIG. 13  depicts the detent  174  engaged in a third indentation  186  of the plurality of indentations  172  to signify that adjuster ring  114  is in a third position.  FIG. 14  shows the detent  174  engaged in a fourth indentation  188  of the plurality of indentations  172  to signify that the adjuster ring  114  is in a fourth position.  FIG. 15  illustrates the detent  174  engaged in a fifth indentation  190  to signify that the adjuster ring  114  is in a fifth position. 
     While the figures depict five (5) indentations  172  to signify five (5) predetermined positions of the adjuster ring  114 , it is contemplated that more or less than five (5) indentations  172  may be used to signify more or less than five (5) predetermined positions of the adjuster ring  114 . 
       FIG. 16  illustrates a bottom perspective view of the stroke mechanism  100  in the first position and also with the locking plate  156  in the locked position  191 . As described above, the orifice  162  contains a notch  164 , which, when in the located position, engages the backing plate mount  152  to prevent movement of the bearing axle  148  and the bearing carriage  136 , and, as a result, prevents movement of the adjuster ring  114 . 
       FIGS. 17-21  show a bottom perspective view of the stroke mechanism  100  in a number of predetermined locations with the locking plate  156  in the unlocked position  192 . The combination of figures illustrates the movement of the bearing axle  148  as the adjuster ring  114  is rotated, resulting in a change in the stroke. 
       FIG. 22  illustrates a side view of a stroke mechanism  200 , according to an alternative embodiment of the invention. In this embodiment of the invention, the backing plate mount  152  is replaced with a backing plate mount  202 . A cross-sectional view of the backing plate mount  202  is shown in  FIG. 23 . As depicted in  FIG. 23 , the backing plate mount  202  includes an outer thread  204  and an inner thread  206 . As such, the backing plate mount  202  is able to interfit with a variety of backing plate sizes. 
       FIG. 24  illustrates a top perspective view of a stroke mechanism  208 , according to an alternative embodiment of the invention. In this embodiment of the invention, the plurality of indentations  172  of the housing  102  is replaced with a locking pin  210 . Additionally, the detent  174  of the adjuster ring is replaced with a plurality of indentations  212 , similar to the plurality of indentations  172  shown in  FIG. 3 . That is, the locking pin  210  is configured to interfit when a respective one of the plurality of indentations  212  when in a locked position. On the other hand, when the locking pin  210  is in an unlocked position, the adjuster ring  114  is able to be rotated. The locking pin  210  includes a spring  214  configured to maintain the locking pin  210  in the locked position unless the locking pin  210  is manually moved to and maintained in the unlocked position by a user. 
     In the representative embodiment of the invention, a covered channel  216  is formed in the outer surface  168  of the top plate  108  of the housing  102 . The locking pin  210  and the spring  214  are housed within the covered channel  216 . While  FIG. 24  shows the covered channel  216  along the entire length of the outer surface  168  of the top plate  108 , it is contemplated that the covered channel  216  may exists along any distance along the outer surface  168  of the top plate  108 . 
     It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein, but includes modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.