Abstract:
A planetary grinding machine having a simple design with a minimal number of parts, which are all easily accessible for maintenance and repair is disclosed. The machine has a rotating planetary disk with rotating screeding disks attached. The planetary disk is driven by a shaft extending through a top housing cover plate, which supports a transmission driven by a motor. As the planetary disk rotates, a single belt engages a stationary gear on the cover plate and pulleys on screeding disk shafts to turn the screeding disks as the planetary disk is turned. The belts and pulleys for the drive mechanism are sandwiched between the planetary disk and the top cover to protect the mechanisms from dust and debris. The bearings are sealed to prevent dust and debris from entering and oil from escaping. The bearings, being on the inside of the planetary disk, keep oil from landing on the floor.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a planetary grinder for abrading floor surfaces with a rotating circular planar surface tool and more particularly to the planetary drive mechanism of the planetary grinder. 
   2. Description of the Related Art 
   Presently available disk floor abrading machines have separate means for rotating the planet disk and the screeding disks mounted thereon which requires a complicated and difficult to maintain mechanism for providing power to the screeding disks and the planetary disk. 
   In some designs there are multiple gears or multiple belts needed to drive the planet disk and the screeding disks. Other designs have counter-rotating screeding disks which add complications to the design. 
   Some disk floor abrading machines expose their working mechanisms to dust, debris or abraded particles which reduce the life of the machine due to extra wear on the parts. Other machines have hard to reach parts for making adjustments or repairs. 
   It is desirable to have a simple to make, simple to maintain, low cost and reliable means to power the screeding disks and the planetary disk of a planetary grinder without exposing the working mechanism to dust, debris and other particles. 
   SUMMARY OF THE INVENTION 
   The planetary grinder has a top cover plate for supporting a motor and a transmission on its top surface, for easy access, for maintenance and repair and to keep the motor and transmission free from dust and debris resulting from the floor screeding process. The planetary grinder has a rotating planetary disk driven from the transmission&#39;s output shaft under the cover plate for supporting a plurality of rotating screeding disks. The driving mechanism for the screeding disks is sandwiched between the top cover plate and the planetary disk to protect the bearings and belts therebetween from dust and debris. The bearings for the transmission shaft and the screeding disks are sealed to further protect the parts from excess wear due to dust and debris. The top cover plate has a stationary gear attached for engaging a single toothed belt to drive the screeding disks. The belt engages the stationary gear such that, as the planetary disk rotates, the belt turns the pulleys on the screeding disk shafts to rotate the screeding disks at a speed in proportion to the rotation speed of the planetary disk. The screeding disks can be rotated in the opposite direction from the rotation of the planetary disk to counter the torque created thereby and make the planetary grinder easier to control by the user. 
   The planetary disk assembly is easy to remove from the transmission&#39;s output shaft to expose all the moving parts in the mechanism for cleaning, maintenance and repair or replacement of the parts. The design is simple to repair, having only one belt which drives all the screeding disks. 
   A plurality of adjustment pulleys are used adjacent the screeding disk pulleys to adjust the belt tension. Balancing blocks are used to balance the rotating planetary disk. 
   The wheels supporting the planetary grinder are set back from the planetary disk by arms which allow the planetary disk to be tilted perpendicular to the floor to expose the cutting tools and the screeding disks for ease of access during maintenance or repair. 
   OBJECTS OF THE INVENTION 
   It is an object of the invention to provide an easy to maintain and easy to repair planetary grinder. 
   It is an object of the invention to provide an external transmission on top of the housing. 
   It is an object of the invention to provide an external motor on top of the housing. 
   It is an object of the invention to provide sealed bearings on all the shafts to protect them from dust and debris. 
   It is an object of the invention to have the drive mechanism sandwiched between a top cover plate and the planetary disk to protect the drive mechanisms from dust and debris. 
   It is an object of the invention to have the top cover plate support a stationary gear constituting a main driving gear. 
   Other objects, advantages and novel features of the present invention will become apparent from the following description of the preferred embodiments when considered in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the planetary grinder. 
       FIG. 2  is a perspective view of the planetary grinder with the drive disk tilted up. 
       FIG. 3  is a perspective view of the planetary disk without any parts mounted thereon. 
       FIG. 4  is a perspective view of the planetary disk with the drive mechanism installed thereon. 
       FIG. 5  is a perspective view of an alternative drive mechanism with a different belt tightening method. 
       FIG. 6  is a perspective view of the planetary scrubber shaft with break way pins unassembled. 
       FIG. 7  is a perspective view of the planetary scrubber shaft with break way pins assembled. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The planetary grinder  10  is shown generally in  FIG. 1 . It has a motor  12  which is preferably an electric motor and a transmission  14  attached to the motor  12 . Although an electric motor is preferred, any kind of motor or engine for providing power can be used. The transmission  14  is attached to the top of a housing  20 . Wheel mounts  22  are attached to the top of the housing  20  on each side of the transmission  14  and have arms  24  pivotally attached to the wheel mounts  22 . T-bolts  25  are used to secure, either locked down or pivotally, the housing  20  in place relative to arms  24  to position the plane of the housing top  20  parallel to the floor to be worked on or perpendicular to the floor for maintenance of the screeding disks  50 . The length of the arms  24  are preferably longer than the height of the motor  12  and the transmission  14  such that when the housing  20  is tilted perpendicular to the floor, the top of the motor  12  will clear the axle housing  26  at the end of the arms  24 . Wheels  30  are attached to axles in the axle housing  26 . The housing  20  sits close to the floor for a low profile of the planetary grinder  10 , allowing the planetary grinder  10  to get under objects, such as shelving, while screeding the floor. 
   Handle mounts  32  are attached to the axle housing  26  for pivotally attaching a handle shaft  38  to the axle housing  26  by brackets  36  having adjustment apertures  31  and pin  35  for selecting an aperture in handle mount  32  to set the handle shaft  38  at the desired angle for operation of the planetary grinder  10 . The handle shaft  38  pivots about bolt  37  through an aperture in brackets  36  and an aperture in handle mounts  32 . 
   The length of the handle is adjustable as shaft  42  telescopes inside of handle shaft  38  and can be fixed at a desired length by T-bolt  40  engaging threads on handle shaft  38  and pressing against shaft  42 . 
   A handle  45  on the top end of shaft  42  allows the user to push, pull or steer the planetary grinder  10 . 
   The planetary disk  60  is driven by the output shaft of the transmission  14  and rotates while supporting screeding disks  50 , which also rotate. The screeding disks  50  move in circles relative to the planetary disk  60  as the screeding disks  50  rotate on their axles. Hence, the floor experiences rotating screeding disks  50  engaging it while driven in a circular pattern by the planetary disk  60  while the planetary grinder  10  being pushed back and forth over the floor on wheels  30 . The floor is therefore engaged by a plurality of screeding disks  50  having a cutting tool or abrading tool rotating to cover all portions of the floor as the planetary grinder  10  is maneuvered over the floor. 
   Sandwiched between the planetary disk  60  and the housing  20  is the drive mechanism which rotates the screeding disks  50 . All of the moving parts for rotating the screeding disks  50  are mounted on the planetary disk  60  and are sandwiched between the planetary disk  60  and the housing  20 , thus sealing all the bearings and the oils associated therewith above the planetary disk  60  so that the floor is protected from oil, grease and dirt emanating from the drive mechanism. The working mechanism is all contained between the planetary disk  60  and the housing  20  within a small height, making for a low profile planetary grinder. 
   The hub  62  on planetary disk  60  rotatingly engages stationary gear  65  by use of a bearing  68 . A snap ring  67  is used to quickly and easily detach the hub  62  and thus the planetary disk  60  from the stationary gear  65 . A gear mounting plate  69  attaches to drive gear  65  by bolts in apertures  61 . Drive gear  65  is attached to the undersurface of the housing  20  by bolts  63  through housing  20  inserted into threaded apertures  61  in the gear mounting plate  69  attached to stationary gear  65 , thus keeping the stationary gear  65  fixed in place while the planetary disk  60  rotates. When bolts  63  are removed housing  20  and gear mounting plate  69  are quickly easily detached and the working mechanism is exposed for ease of repair and maintenance. The ease of maintenance and repair reduces downtime making the planetary grinder  10  more efficient. 
   Hub  62  is attached to the output of shaft of transmission  14  such that planetary disk  60  rotates when the motor  12  is on and the transmission  14  is engaged. With planetary disk  60  rotating and stationary gear  65  fixed, belt  70  transmits power to the screeding disk pulleys  74  which connect to the screeding disks  50  by an axle passing through screeding disk apertures  64  in the planetary disk  60 . In this manner the motor  12  rotates both the planetary disk  60  and the screeding disks  50  with a simple, easy to adjust, easy to maintain mechanism. As shown, a single endless belt  70  has teeth that engage the stationary gear  65  and the screeding disk pulleys  74 . Although a toothed belt  70  is shown, a chain drive, a v-belt or other means for transmitting power maybe used to connect the stationary gear  65  to the screeding disks  50  by way of screeding disk pulleys  74 . 
   Alternatively, a belt  70  with teeth on both sides may be used such that the idler pulleys  72  have the benefit of a geared pulley and the teeth of the belt  70  engaging. Also with a double-sided toothed belt, the belt can be moved from one side of the screeding disk pulley  74  to the opposite side causing the screeding disk  50  to spin the opposite direction. Using this method for selecting the spin direction of the screeding disks  50 , planetary grinders having four screeding disks can have two screeding disks spinning in one direction and two screeding disks spinning in the opposite direction. 
   As shown, when planetary disk  60  rotates in direction of arrow  80 , the screeding disk  50  will rotate in the opposite direction of arrow  82 , thus providing stability of the planetary grinder  10  by having planetary disk  60  counter-rotating to the direction of rotation of the screeding disks  50  which engage the floor with an abrading tool. 
   It is preferable to use sealed bearings on the idler pulleys  72  and the screeding disk pulleys  74  to keep oils from landing on the floor and to protect the bearings from dust and other particles. Sandwiching the idler pulleys  72  and the screeding disk pulleys  74  and the driving mechanism between the planetary disk  60  and the housing  20  helps to keep the abraded flooring material, dust, dirt and other particles from interfering with the drive mechanism and getting into the bearings, on the belts, and on the moving parts, which will cause wear on the parts. 
   As shown in  FIG. 4 , idler pulleys  72  are on adjustment bars  90  having adjustment slots  92  and adjustment bolts  94  for locking the adjustment bars  90  in place. In this manner belt  70  can be easily installed and the tension thereon adjusted, making it easy to change belts if needed. Adjustment blocks  96  and  98  can be used in conjunction with adjustment bolt  99  and tension springs  95  to move the adjustment bars  90  for balancing the planetary disk  60  as it spins. The tension springs  95  help keep a desired tension on belt  70 . Adjustment blocks  96 ,  98  maybe of different weights to help balance planetary disk  60 . 
   It is preferred to have a break-a-way safety clutch plate  85  with a pin  86  made of plastic or metal, such that if a nail or other object is struck by a screeding disk  50  or an abrading tool attached thereto, the pin  86  will shear, so damage to the planetary grinder  10  will be prevented and the safety of the operator will be enhanced.  FIG. 6  and show the break-a-way safety clutch plate  85  with break-a-way pin  86  for insertion into apertures  89  on screeding disk connectors  87 . 
   A shroud  52  is provided on housing  20  to block debris, dust and abraded material from leaving the area under the drive disk and to aid in vacuuming when a vacuum is attached. There can be one or more ports in the shroud  52  for connection to a vacuum system attached to the planetary grinder  10 . The ports may be in various locations around the shroud  52 . A vacuum dust collection bag may be attached to the handle shaft  38 . The shroud  52  can be attached with a hook and loop fastener such as VELCRO® for ease of height adjustment and can be long enough to engage the floor for vacuum efficiency and confining debris and dust. In addition to the vacuum, a water dispenser can be added to inject water under the shroud  52  to help keep the dust down. 
   The motor  12  and transmission  14  being on top of the housing  20  make it easy to repair, replace or maintain the motor  12  and transmission  14 . Similarly, the belt  70 , pulleys  72 ,  74  and the stationary gear  65  are easily accessible and adjustable for ease of maintenance and repair. The hub  62  can be easily removed from the stationary gear  65  with the use of a gear puller. 
   Planetary disk  60  can be balanced with all parts installed thereon by use of a bubble balance and balance weights such as used on car wheels. 
   In an alternative embodiment shown in  FIG. 5  the tension belt  70  can be regulated by springs  101  which connect pin  102  attached to planetary disk  60  to pin  103  on pivotable idler bracket  105  having idler wheel  106  which pivots about aperture  110  which has a fastener connecting it to planetary disk  60 . A guide slot  120  in pivotable idler bracket  105  may be used to help align the pivotable idler bracket  105  when a pin is used in aperture  125  on planetary disk  60 . 
   Different sized planetary disks  60  can be used with different sized motors and different transmissions. Similarly different pulley wheel sizes and belts may be used to control the speeds of the screeding disks  50 . The screeding disks  50  may have different cutting or abrading tools attached depending on the cutting, polishing, sanding or other operations to be performed. 
   One advantage of using a belt drive with screeding pulleys  74  and idler pulleys  72  is that the size of the pulley wheels can be easily changed thus changing the ratios of the stationary gear  65  to the gear on the screeding disk pulley  74  and thus the rational speed of the screeding disks  50  on the floor. The higher the ratio of the screeding disk gear to the drive stationary gear  65 , the smoother the operation of the grinder. The ratios can be on the order of 4.3 to 1 and 7 to 1. Thus a quick and easy change of pulleys can change the performance of the grinder  10  depending on floor materials, and cutting tools used giving the belted grinder greater versatility over gear-to-gear grinders. 
   Another advantage of the belt drive planetary grinder is the ability to change from a screeding disk  50  with the axle centered in the disk to an off-center stationary gear  65  for eccentric screeder disks  50 , which may be preferred for wood floors. The screeder disks  50  can be quickly and easily changed by removing the belt  70  from the screeder disk pulley  74  and inserting an eccentric screeder disk  50  and its associated pulley and the replacing the belt. Similarly, satellite disks may be used on a screeder disk and the disks easily changed. 
   Wheels  30  are preferably placed close enough together so that they are within the diameter of the housing  20 . The planetary grinder  10  can then be used along walls without the wheels  30  interfering when the housing  20  is adjacent to the building&#39;s wall. The screeding disks  50  come close to the edge of the planetary disk  60  to screed the floor as close to a wall as possible. The wheels  30  being close together allows the planetary grinder  10  to walk straight down a wall and have greater pivot maneuverability. 
   Shaft  42  or handle  45  can have the planetary grinder controls, such as the motor on/off switch, mounted thereon. 
   Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.