Abstract:
A floor preparation machine that uses a number of vertical needles positioned in a tight rectangular pattern. The needles vibrate against the floor surface to prepare the floor surface. The needles are driven by a cam and cam follower. As the cam is turned by a motor, a number of ribs repeatedly contact the cam follower, which in turn repeatedly pushes the needles down. Under the top plate that supports the needles, is a rubber form that acts as a “spring” to force the needles up after they have been pushed down by the cam follower. In practice, the system produces a sustained vibration of the needles that breaks the surface to a depth of 1/16 to ⅛ of an inch.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   Not Applicable 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
   Not Applicable 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates floor refinishers and particularly to a floor refinisher using needles to break epoxy coatings. 
   2. Description of the Prior Art 
   Modern floors in commercial buildings are often finished with epoxy coatings. This produces a durable smooth finished surface. Overtime, however, these surfaces wear and need to be resurfaced. Before a new surface layer of epoxy coating can be poured, the original surface must be prepared. This is normally accomplished by roughing up the surface to break up the old coating. This is normally done to a depth of between 1/16 and ½ of an inch. This prepared surface is then able to take a new coating of epoxy that is smooth and like new. 
   The current method used to prepare the surface of the floors involves the use of a shot blaster. A shot blaster is a device that uses small steel balls (shot) that are blasted into the floor surface. A machine holds the shot and provides the force for blasting them into the floor. The machine has a powerful vacuum to pull the shot back into the machine as they are blasted out. This machine does produce a properly prepared floor for refinishing. However, they have some problems. First, they are large. Even the smaller units are too large to fit easily into corners. This means that the edges of the floor have to be broken up by hand. This is a slow and difficult process that can result in injuries to workers. Another problem is that the use steel shot—typically a thousand pounds of shot or more are required for a typical job. This increases shipping costs, especially to rural areas. Furthermore, despite the powerful vacuum, the machine does not recover all of the shot pellets. This means that workers must take time to clean up the shot pellets after the job. It also requires extra quantities of shot be kept on hand to refill the machine as needed. This further increases the cost of the job. 
   Another device that can be used for floor preparation is a head scabbler. This device uses carbide percussive cutting heads to pound the floor surface. The heads are circular and have four protrusions per head that contact the floor surface. The heads are also positioned in a rectangular spaced-apart pattern. The device is small it has a 12 inch wide cutting path. This is a powerful machine that can do the job, but still is not large enough to do large areas efficiently. Moreover, the spaced-apart pattern of cutting heads requires the operator to mover over an area multiple times to ensure a properly prepared surface. Finally, the spaced-apart pattern does nothing to help prepare the edges of a room. This means that these areas must be done by hand also. 
   BRIEF DESCRIPTION OF THE INVENTION 
   The instant invention overcomes these problems. It is a floor preparation machine that uses a number of vertical needles positioned in a tight rectangular pattern. The needles vibrate against the floor surface to prepare the floor surface without the intensity of a shot blaster or the head scabbler discussed above. The needles act in a similar manner to an engraver&#39;s tool working on metal. Moreover, because the needles are positioned in a tight pattern, there are no missed areas left when a machine completes a pass. Finally, the placement of the needles is such that the machine can be operated immediately adjacent to walls, which eliminates all handwork to finish the edges. 
   In the preferred embodiment, the needles are positioned into a rectangular form. They are secured by a top plate that that fits into a frame that permits the top plate to move vertically. The needles are driven by a cam and cam follower. The cam is turned by a motor. The cam is a cylinder that has a number of ribs extending out from the surface. The cam follower is positioned below the cam. As the cam is turned, the finds repeatedly contact the cam follower, which in turn repeatedly pushes the needles down. Under the top plate that supports the needles, is a rubber body. The rubber acts as a “spring” to force the needles up after they have been pushed down by the cam follower. 
   In practice, the system produces a sustained vibration of the needles that breaks the surface to a depth of 1/16 to ⅛ of an inch. 
   Thus, with one machine it is possible to completely prepare a floor with one continuous operation. Moreover, because the unit is self-contained, there are not large quantities of shot pellets to carry, as in the case of the shot blaster. Finally, because the needles operate with less impact, the machine can be made large enough to cover a reasonable area of the floor with each pass, which reduces the time spent on the floor preparation. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view of the invention. 
       FIG. 2  is an interior side view of the invention showing the major internal components of the invention. 
       FIG. 3  is a rear view of the invention. 
       FIG. 4   a  is a left side front perspective view of the needle drive assembly. 
       FIG. 4   b  is a right side front perspective view of the needle drive assembly. 
       FIG. 5  is a detail view of the cam cylinder. 
       FIG. 6  is a detail view of the needle drive housing showing the can follower compartment. 
       FIG. 7  is a perspective top view of the cam follower. 
       FIG. 8  is a side view of the cam follower. 
       FIG. 9  is a cross-sectional view of the cam follower taken along the lines  9 — 9  of  FIG. 8 . 
       FIG. 10  is a cross-sectional view of the cam follower taken along the lines  10 — 10  of  FIG. 8 . 
       FIG. 11  is a side perspective view of lower portion of the needle drive housing. 
       FIG. 12  is a front view of the needle assembly. 
       FIG. 13  is a diagrammatic view of the needle drive assembly, showing the placement and relationship of all the parts of the drive assembly with no housing shown. 
       FIG. 14  is an end view of an electromagnet as part of a second embodiment of the needle drive unit. 
       FIG. 15  is a side view of an electromagnet as part of a second embodiment of the needle drive unit. 
       FIG. 16  is a top view of a single needle head in the second embodiment. 
       FIG. 17  is a top view of a number of needle heads positioned in sequence. 
       FIG. 18  is a diagrammatic view of the needle drive assembly of the second embodiment showing the placement and relationship of the key parts of the drive assembly with no housing shown. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to  FIGS. 1 and 2 , the invention  1  consists of a frame and housing  3  that supports a number of components. The machine  1  is designed to operate on wheels  5 . It has a housing  3  that holds a drive motor  4 , to drive a set of wheels  5 . A needle drive system  6  is also provided to operate the needles  7  that are mounted in the front of the machine. 
   A vacuum  8  that has a duct  9  that connects to the needle drive system  6  at nozzle is provided to help remove dust produced by the machine. 
   The machine  1  has a control panel  11  mounted on the top. The control panel includes controls that control the speed or intensity of the needles in their application to the floor surface. The machine has a handlebar  15 . The handlebar  15  is used to control the direction and speed of the drive motor  4  by the operator. In the preferred embodiment, it has a “dead man” drive bar to shut down the machine when the handlebar is released. 
     FIG. 3  is a rear view of the invention. Here, the housing  3 , wheels  5 , control panel  11  and the handle  15  are shown. 
     FIG. 4   a  is a left side front perspective view of the needle drive assembly  6 . This assembly consists of several components, discussed below. All the components, except for the motor  20 , are housed in a housing  21 . The motor  10  is an industrial type with a typical speed of 1800 rpm and a horsepower of ???. The motor  20  is bolted to the top of the housing  21  as shown. 
     FIG. 4   b  is a right side front perspective view of the needle drive assembly. Here, the motor  20  is shown as before. The door  22  to the cam cylinder is removed, showing the cam cylinder  23 . The motor  20  drives the cam cylinder to operate the machine. The motor has an output shaft  24  that mechanically connect to the cam cylinder shaft  25 .  FIG. 13  shows gears  27  and  28  for this mechanical connection, but other methods, such as drive belts may be used. The gears are covered with a guard  26  for safety as well as cleanliness. 
     FIG. 5  is a detail view of the cam cylinder  23 . The cam cylinder has a cylindrical body  30  that has a number of ribs  31  extending outward from it. The cylinder body has a shaft  25  and supported on the ends by bearings in square housings  32  that conform the outer housing  21 . 
     FIG. 6  is a detail view of the upper portion of the needle drive housing  21  showing the can follower compartment. Here, the guard  26  and gear  28  are shown along with the motor  20 . At the base of the upper part of the housing  21  is a compartment  36  for the cam follower. Note that the cam  30  and one of the ribs  31  can be seen in the center portion of the upper portion of the housing. 
   The cam cylinder and cam follower act as a “means for periodically compressing said top plate in a downward motion for a limited period of time”. This produces a number of “compression periods” and a number of “non-compression periods”. 
     FIG. 7  is a perspective top view of the cam follower  40 . The cam follower  40  has an ovular body  40   a . The top has a number of roller bearings  41  that are shaft-mounted in the body (see  FIG. 9 ). As the cam is turned, the ribs make contact with the roller bearings on the cam follower, which is then pushed downward to make contact with the needle plate (see below). Roller bearings are preferred because the do not heat up excessively during the operation of the machine. Note that the spaces in between the groups of bearings are filled with shaft support members  42 . 
     FIG. 8  is a side view of the cam follower  40 . As mentioned above, the roller bearings  41  are shown. To keep the bearings lubricated, oil is pumped into the upper portion of the housing. To retain the oil, o-rings  44  are placed around the follower body as shown. The o-rings act like piston rings in a piston engine to retain the oil as the follower is reciprocated within the housing. 
     FIG. 9  is a cross-sectional view of the cam follower taken along the lines  9 — 9  of  FIG. 8 . Here, a roller bearing  41  is shown with the bearing shaft  45  through the center. In the preferred embodiment, the bearings are 1-inch o. d. and ½-inch wide. The bearing shaft has a ½-inch o. d. 
     FIG. 10  is a cross-sectional view of the cam follower taken along the lines  10 — 10  of  FIG. 8 . Here, a section of the shaft support  46  is shown. The shaft support  46  is a series of portions of the cam follower that maintain the shaft in position. The shaft support section also retains the bearing sets in position. Note that the shaft support sections also contain caps that fit over the shaft to secure it in place. 
     FIG. 11  is a side perspective view of lower portion  50  of the needle drive housing. This piece acts as the needle support. Note that wheels  5  can be attached to the housing, if desired. The vacuum nozzle  10  is shown attached to the housing as well. The lower portion has a number of holes  51  that retain the needles. Note that the top of the lower portion forms a trough  52  that holds the drive plate and rubber piece (discussed below). 
     FIG. 12  is a front view of the needle assembly  54 . This assembly has a number of needles  55  in a multiple row configuration.  FIG. 11  shows five rows of needle supports. In the preferred embodiment, each row has 42 needles. Of course, these numbers and configurations can be varied, as desired. The important thing is that sufficient needles are used to create a tight pattern, which provides the most efficient floor treatment. The needles are held in place by a metal plate  56 , which fits into the trough  52  on the lower portion  50 . The cam follower makes contact with this plate as it is pushed down by the cam. Below the metal plate  56  is a rubber form  57 . The rubber form is a resilient member. This form also sits in the trough  52  under the metal plate  56 . After the cam follower has pushed the metal plate down, the rubber form resiliently causes the metal plate to rise in anticipation of the next operation of the cam ribs on the cam follower. Thus, the rubber form acts as a “means for moving said top plate upward during said number of non-compression periods”. In this way, the needles are reciprocated in the housing to make contact with the floor surface. 
     FIG. 13  is a diagrammatic view of the needle drive assembly, showing the placement and relationship of all the parts of the drive assembly with no housing shown. Here, the motor  20  is shown above the cam cylinder  23 . Gears  27  and  28  are shown attached to their appropriate shafts. An discussed above, the motor turns the cam cylinder  23 , which in turn causes the cam follower  40  to be pushed down against the top plate  56 , which in turn pushes down the needles  55 . The downward motion happens every time one of the ribs on the cam cylinder contacts the cam follower. In between contacts by the ribs, the rubber form  56  pushes up the top plate, which raises the needles for the next stroke. In this way, the needles are reciprocated at a high rate of speed. This is highly effective in breaking up the top surface of a concrete floor. Typical travel of the needles is between about 1/16-inch and 3/16-inches. 
     FIGS. 14 and 15  show an electromagnet as part of a second embodiment of the needle drive unit. The electromagnet  60  is a cylinder that has a pair of wires  61  the feed from it. These wires connect to a power source  77  (see  FIG. 18 ). 
     FIG. 16  is a top view of a single needle head or needle set  63  in the second embodiment. In this embodiment, the needles are separated into distinct groups.  FIG. 16  shows one set  63  that has a number of needles  64 . Note that the needle pattern can be varied and is not limited to that shown. 
     FIG. 17  is a top view of a number of needle sets positioned in sequence. Note that the end pieces  65  have squared ends to fit into the frame. However, the opposite end is angled. This is done to allow the needles to seat properly in the unit. Note that the center portions  63  are angled on both ends, as shown. Note that the preferred angle is about 30 degrees. 
     FIG. 18  is a diagrammatic view of the needle drive assembly of the second embodiment showing the placement and relationship of the key parts of the drive assembly with no housing shown. Here, the motor and cams structure is eliminated. The magnet  60  is positioned above the needle assembly as shown. The magnet&#39;s wires connect to a power source  77  as shown. This power source is suitable for the magnet to operate. 
   The needle assembly is similar to that of the first embodiment, except that in this embodiment, there is a top steel plate  70 , a center rubber portion  71  and a bottom steel plate  72 . In this way, the magnet works to lift the needles in one part of the cycle and the rubber works to return the needles to their lower position for the next up cycle. 
   Due to the high frequency and speed of operation, the rubber portion in both embodiments must be a rubber capable of handling high temperatures and a high duty-cycle of compression cycles. 
   The present disclosure should not be construed in any limited sense other than that limited by the scope of the claims having regard to the teachings herein and the prior art being apparent with the preferred form of the invention disclosed herein and which reveals details of structure of a preferred form necessary for a better understanding of the invention and may be subject to change by skilled persons within the scope of the invention without departing from the concept thereof.