Patent Publication Number: US-6907874-B1

Title: Concrete hole cutting machine

Description:
FIELD OF THE INVENTION 
   The present invention relates to concrete saws and more particularly to a drum type concrete saw machine for cutting a hole in a concrete slab. 
   BACKGROUND OF THE INVENTION 
   Government safety regulations now require that posts be erected in some existing concrete slabs found in commercial and industrial sites. To erect a post in an existing concrete slab, requires that a circular hole be cut into and through the slab. Once a hole is cut into the slab a post is inserted into the hole and securely stationed therein by conventional means. The problem lies in cutting the circular hole in the concrete slab. This task is difficult, time consuming and in the end very expensive. Typically circular holes are cut in concrete slabs by a drum type concrete saw that is adjustably supported for up and down movement on a post that is in turn supported on a platform that rests on the concrete slab. However, it is important that the platform that supports the concrete saw be stable. In order to stabilize the platform during a hole cutting operation, the platform is typically bolted to the concrete slab prior to moving the saw into engagement with the concrete. Simply bolting and securing the supported platform to the concrete slab is time consuming. In any event, once the platform is bolted to the concrete slab, the circular drum saw is lowered into engagement with the concrete slab. An operator controls the lowering of the saw and once the saw comes into contact with the surface of the concrete slab, the operator simply continues to lower rotary saw such that it cuts through a concrete slab which would typically be approximately 8″ thick. Once the concrete saw has cut through the slab, the cut chunk of concrete, which is cylindrical in shape, is removed and a post inserted into the hole. 
   Concrete saws of the type discussed above are not portable. Therefore the entire concrete saw along with the platform has to be moved to another location on the slab for cutting the next hole. This process is inconvenient and as noted above, a great deal of time and effort is expended in cutting each hole. 
   Therefore, there has been and continues to be a need for a machine for cutting holes in concrete that will efficiently and cost effectively cut holes in concrete. 
   SUMMARY OF THE INVENTION 
   The present invention relates to a concrete hole cutting machine that is adapted to mount to a lift arm of a prime mover such as a front-end loader. The machine comprises a connector for mounting the concrete hole cutting machine to one or more lift arms of the prime mover. A first frame structure is coupled to the connector. A second frame structure is extendably and retractably coupled to the first frame structure and adapted to support a concrete hole cutting saw. The second frame structure is movable back and forth with respect to the first frame structure. An actuator is provided for extending and retracting the second frame structure with respect to the first frame structure. It follows that the position of the concrete hole cutting saw supported by the second frame structure can be adjusted and varied by actuating the actuator which causes the second frame structure to be extended or retracted with respect to the first frame structure. 
   The present invention in one embodiment entails a concrete hole cutting machine that is adapted to be mounted to a front-end loader or other vehicle or prime mover. The machine comprises a first frame structure and a connector that extends from the first frame structure and connects to the adapter of the front-end loader such that the first frame structure is connected to the front-end loader. A second frame structure is provided and this frame structure supports a rotary concrete cutting saw. The first and second frame structures include a telescoping structure that includes one member that slides back and forth in a second member. The telescoping structure is oriented with respect to the connector such that the second frame structure and saw supported directly or indirectly thereby can be moved back and forth laterally with respect to the front-end loader when the concrete hole cutting machine is connected to the loader. A hydraulic cylinder is interconnected between the first and second frame structures for moving the second frame structure and the concrete cutting saw laterally back and forth between a retracted position and an extended position. 
   Therefore, it is appreciated that the concrete hole cutting machine can be easily positioned such that the concrete cutting saw overlies and aligns with a target area to be cut. That is, the concrete saw can be first positioned with respect to a target area by simply positioning the front-end loader or tractor to where the concrete saw lies close to or in the vicinity of the target area. Next, the second frame structure can be shifted laterally back and forth with respect to both the first frame structure and the loader such that the concrete saw lies precisely over the target area. Then the concrete saw can be lowered into engagement with the target area for cutting a hole in the concrete slab. 
   The present invention also entails a method of aligning a drum type of concrete hole cutting saw with a target area in a concrete slab. A concrete hole cutting machine is mounted to a vehicle such as a front-end loader and the vehicle or front-end loader is positioned such that the concrete saw lies relatively close to a target area in a concrete slab. The concrete saw is mounted to a frame structure that can be shifted back and forth with respect to the vehicle or loader. Thus once the loader or vehicle has positioned the saw relatively close to the target area, then the saw can be shifted laterally back or forth to where the saw precisely overlies the target area. Then the drum type concrete saw can be lowered into cutting engagement with the underlying concrete slab. 
   More particularly, and in one embodiment, the present invention entails a method of cutting a hole in a concrete slab with a concrete cutting machine having a drum type rotary cutting saw where the machine is mounted to a front-end loader. The method includes raising the concrete hole cutting machine off the surface of the concrete and moving the front-end loader to a position where the saw is located in the vicinity of the target area or where a hole is to be cut in the concrete. Then the method entails laterally shifting the saw relative to the front-end loader to where the saw aligns with the target area or the area where the hole is to be cut into the concrete. Once aligned, the concrete hole cutting saw is lowered into engagement with the concrete in the target area. Thereafter the concrete saw is continued to be lowered into engagement with the concrete where the concrete saw cuts a hole into the concrete. 
   Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the concrete hole cutting machine of the present invention. 
       FIG. 2  is a front elevational view of the machine shown in the retracted position. 
       FIG. 3  is a view similar to  FIG. 2 , but with the machine in an extended position. 
       FIG. 4  is a fragmentary perspective view illustrating how the front end loader is connected to the machine. 
       FIG. 5  is a schematic illustration showing the operation of the machine. 
       FIG. 6  is a schematic illustration of the hydraulic system that powers the machine. 
   

   DESCRIPTION OF THE INVENTION 
   With further reference to the drawings, the concrete hole cutting machine of the present invention is shown therein and indicated generally by the numeral  10 . As will be appreciated from subsequent portions of the disclosure, machine  10  is designed to cut holes in concrete slabs. Machine  10  is designed to be connected to a front-end loader indicated generally by the numeral  12 . When connected to the front-end loader  12 , machine  10  can be easily moved from one location to another location on a concrete slab and appropriately aligned with a target area such that a concrete saw, forming a part of the machine, may be lowered into engagement with the underlying concrete slab and a hole or cylindrical chunk of concrete cut from the slab. 
   Briefly reviewing front-end loader  12 , it is noted that details of the front-end loader  12  are not dealt with herein because such is not per se material to the present invention and further front-end loaders are well known in the art and are manufactured and sold by a number of manufacturers. In any event, front-end loader  12  includes a pair of hydraulically actuated lift arms  14 , a plurality of wheels  16  and a cab  18 . In conventional fashion, the front-end loader  12  is typically a skid steer vehicle and includes an onboard hydraulic system that powers a hydrostatic drive, the lift arms  14  and various implements that might be connected to the front-end loader  12 . It should be noted that the concrete hole cutting machine  10  could be connected to various prime movers, tractors and other vehicles. In a preferred use, the prime mover, tractor or vehicle would have the capacity to lift the hole cutting machine  10  and move it from location to location. Accordingly, the vehicle that the concrete hole cutting machine  10  is connected to should be provided with one or more lift arms. Herein the term “front-end loader” has been used to refer to the vehicle to which the concrete hole cutting machine is connected. Thus, as used herein, the term “front-end loader” means any type of prime mover, tractor or vehicle that is capable of connecting to and transporting the concrete hole cutting machine  10  from one location to another location. 
   Front-end loader  12  includes an adapter indicated generally by the numeral  20 . Adapter  20  is a conventional structure provided about the front of a front-end loader for connecting to various implements such as a bucket. Basically the adapter  20  comprises a frame structure that is adapted to connect to or mate with a connecting structure associated with an implement or piece of equipment. Details of the adapter  20  are not discussed herein because they are commonly found on front-end loaders. However, in the case of the adapter  20  shown herein, the same includes a pair of levers  20 A and  20 B that actuate a pair of connecting pins (not shown). See  FIG. 4 . When levers  20 A and  20 B are appropriately actuated, the connecting pins are caused to move into engagement with a connecting structure associated with the implement or piece of equipment to be connected to the front-end loader  12 . By the same token, levers  20 A and  20 B can be actuated or moved to cause the connecting pins (not shown) to disengage from the connecting structure of the associated implement. 
   Turning generally to the concrete hole cutting machine  10  of the present invention, the same comprises a number of subsystems or subassemblies. First machine  10  includes a first frame structure indicated generally by the numeral  50 . As will be appreciated from subsequent portions of this disclosure, the first frame structure  50  is adapted to be secured through a connector to the adapter  20  of the front-end loader  12 . 
   A second frame structure, indicated generally by the numeral  60 , is provided. The second frame structure  60  is extendably and retractably coupled to the first frame structure  50 . That is, second frame structure  60  can be extended and retracted with respect to the first frame structure  50 . As is seen in the drawings ( FIGS. 1 and 2 ), second frame structure  60  is designed to be moved laterally back and forth with respect to the front-end loader  12 . 
   Supported on the second frame structure is a concrete hole cutting saw unit indicated generally by the numeral  70 . It is thusly appreciated that the concrete saw unit  70  moves back and forth with the second frame structure  60 . As will be appreciated from subsequent portions of the disclosure, the front-end loader  12  will first position the saw unit  70  relatively close to a target area TA that defines the location in the concrete slab where the hole is to be cut. Once the saw unit  70  is positioned relatively close to the target area TA, then the second frame structure  60  is utilized to position the saw unit directly over the target area TA. 
   In order to power the second frame structure  60  and move the same laterally back and forth with respect to the front-end loader  12 , there is provided an actuator, indicated generally by the numeral  80 . Actuator  80 , as will be described in more detail later, is interconnected between the first frame structure  50  and the second frame structure  60  and is capable of driving the second frame structure  60  back and forth. 
   Finally, there is provided a connector, indicated generally by the numeral  90 , which connects the first frame structure  50  to the adapter  20  of the front-end loader  12 . Connector  90 , as will be appreciated from the drawings, is fixed with respect to the first frame structure  50 . Thus, when the adapter  20  of the front-end loader  12  is moved, both the connector  90  and the first frame structure  50  are constrained to move accordingly. 
   Turning to a more detailed discussion of the subassemblies or subsystems of the present invention, the first frame structure  50  includes an elongated tube  100 . Tube  100  is closed on one end and open on the other end. A foot grip  102  is secured to the top of the tube  100 . Extending downwardly from one end of the tube  100  is a foot or supporting structure. In the case of the design shown in the drawings, the foot or support structure includes a post  104 . Connected to the lower portion of post  104  is a horizontal member  106 . Extending from the horizontal member  106  is a pair of spaced apart supports  108 . As will be appreciated from subsequent portions of this disclosure, when the hole cutting machine  10  is in operation on a concrete slab, this support structure will engage and rest upon the concrete slab. 
   Second frame structure  60  includes an elongated beam  120 . As seen in  FIGS. 1 and 2 , beam  120  projects into tube  100  and is confined therein. A portion of the beam  120  extends outwardly from the open end of the tube. As will be more fully appreciate from subsequent portions of this disclosure, beam  120  is permitted to reciprocate or move back and forth within tube  100 . 
   Extending downwardly from the beam  120  is a foot or support structure that during a hole cutting operation will support at least part of the hole cutting machine  10 . As seen in  FIGS. 1 and 2 , this foot or support structure includes a lower leg  122  that extends downwardly from the beam  120  and connects to a support or platform  124 . The support or platform  124  in turn supports the saw unit  70  to be described below. 
   Extending upwardly from the beam  120  is an upper leg  126 . Extending from an upper portion of the upper leg  126  is a cross connector  128 . Upper leg  126  and cross connector  128  function also to help support and stabilize the saw unit  70 . 
   Now turning to the saw unit  70 , the same comprises a post  150  that is securely mounted or stationed to the support or platform  124 . Post  150  extends vertically upwardly from the support or platform  124 . The cross member  128  of the second frame structure connects to an upper portion of the post  150  and tends to stabilize the post. Post  150  is provided with an elongated gear track  152  that extends along one side of the post. A carrier  154  is mounted on the post  150  and movable up and down thereon. An actuator  156  in the form of a spoke wheel is associated with the carrier  154 . Although not shown, the actuator  156  is coupled to a gear or gear assembly housed within the carrier  154 , which meshes with the gear track  152  on post  150 . Thus, by turning the spoke wheel  156  the carrier  154  can be moved along the post  150 . That is, by turning the spoke wheel  154  in one direction causes the carrier  154  to move downwardly on the post  150 . Turning the spoke wheel  156  in the opposite direction results in the carrier  154  moving upwardly on the post  150 . 
   A support arm  158  is secured to the carrier  154  and extends outwardly therefrom. A drum type concrete hole cutting saw  160  is supported from the support arm  158 . Details of the concrete hole saw  160  are not dealt with herein because such devices are known. Suffice to say that the concrete hole cutting saw  160  assumes a generally cylindrical shape and is made of heavy duty steel. About the lower periphery of the cylindrical drum there is provided a series of teeth that are effective to cut through a concrete slab when the drum type saw  160  is rotated. 
   Although the saw  160  can be driven in various ways, in the embodiment illustrated herein the saw is hydraulically driven by hydraulic motor  162 . During a concrete hole cutting operation it is desirable to direct a small stream of water into the area where the teeth of the saw are cutting the concrete. To accommodate this the present invention provides a water tank  164  that is mounted on the cab of the front-end loader  12 . Connected to the water tank  164  is a supply line  166  that extends downwardly from the water tank to the area where the concrete hole cutting saw  160  is located. During a hole cutting operation a valve can be actuated such that the water tank will supply, under the force of gravity, a light stream of water to the hole cutting saw  160 . 
   To drive the second frame structure  60  back and forth, the actuator  80  includes a double acting hydraulic cylinder  180 . See  FIGS. 1 and 2 . Hydraulic cylinder  180  is connected between the first frame structure  50  and the second frame structure  60 . More particularly, the hydraulic cylinder  180  is anchored through a clevis  182  to the underside of elongated tube  100 . The rod  180 A of the hydraulic cylinder  180  is connected to a clevis  184  that is in turn connected to leg  122 . Thus, by extending the rod  180 , the beam  120  is driven from left to right as viewed in  FIG. 1  and the hole cutting machine  10  is moved to an extended position. In addition, by retracting the rod  180 A, the second frame structure  60  and the beam  120  are retracted and when retracted the hole cutting machine  10  assumes a retracted position shown in  FIG. 1 . The extended position just discussed is shown in  FIG. 2 . 
   Connector  90  is shown in  FIG. 4  and has been briefly discussed above. Connector  90  includes a plate  200 . Extending across the top of plate  200  is an upper angled flange  202 . Extending along opposite sides of the plate  200  is a pair of side retainers  204 . Extending across the bottom of the plate  200  is a lower flange  206  that includes a pair of openings  208 . Openings  208  formed in the lower flange  206  are designed to receive the connecting pins (not shown) associated with the adapter  20 . It should be appreciated, that the upper angle flange  202  and the other surrounding structure around the plate  200  are designed to enable the adapter  20  to be easily inserted and locked into the confines formed around the plate  200  by the upper flange  202 , side retainers  204  and lower flange  206 . 
   A pair of cross beam connectors  210  extend from the tube  100  and connect to the connector  90 . Thus, as discussed above, connector  90  is coupled directly to the first frame structure  50 . 
   To drive the concrete saw  160  and to power the double acting hydraulic cylinder  180 , hydraulics are used. Since the front-end loader  12  includes its own onboard hydraulic system, then it follows that the hydraulic system of the front-end loader  12  can be utilized to power the concrete hole cutting machine  10 . In  FIG. 6  a schematic of a hydraulic system is shown and indicated generally by the numeral  96 . A fluid tank  130  and a pump  232  would typically be provided onboard the front-end loader  12 . A pair of hydraulic lines, a supply line and a return line, would be provided from the front-end loader  12  to the concrete hole cutting machine  10 . In particular, the pump  232  would be connected to a cylinder control valve  234 . Typically the cylinder control valve  234  would be a three positioned valve that would direct hydraulic fluid into the anchor end or the rod end of the hydraulic cylinder  180  depending on whether the second frame structure  60  is being extended or retracted. This control valve would also include a neutral position. Pump  232  would also supply fluid to a saw control valve  236 . The saw control valve would in turn direct fluid to the hydraulic motor  162  which is associated with the saw unit  70 . The saw control valve  236  would be a two position control valve or could be provided with a lock to assure that the saw was only driven in one direction. This is because the teeth on the lower periphery of the drum saw  160  could be damaged if the saw  160  is ran in reverse while the teeth are engaged with the underlying concrete. It should also be appreciated that appropriate relief valves would be provided in customary locations. For example, a relief valve would be provided in connection with the hydraulic motor  162  that drives the saw  160  and appropriate relief valves would be provided with they hydraulic cylinder  180  so as to provide appropriate relief when the valve is actuated and the rod or piston has reached an extreme position within the cylinder. 
   In the schematic of  FIG. 6  the cylinder control valve is referred to separately by the numeral  234  while the saw motor control valve is referred to separately by the numeral  236 . However, in practice these two valves may be consolidated into a single valve structure with a pair of levers, one lever operating one valve and the other lever operating the other valve. Such a consolidated valve structure is shown on the hole cutting machine  10  in  FIGS. 1–3  and referred to by the numerals  234 ,  236 . 
     FIG. 5  is a schematic illustration of how the concrete hole cutting machine  10  works. As illustrated therein, there are three target areas TA formed in a concrete slab. The location of these target areas can be identified by surveying instrumentation such as a laser beam. For purposes of explaining the operation of the machine  10 , each target area TA is said to include an X axis and a Y axis. Typically in a warehouse, the target areas will be laid out in alignment with a certain spacing between consecutive target areas. In some cases the target areas TA can be random. In order to cut holes in the target areas TA, the front end loader  12  with the concrete hole cutting machine  10  mounted thereon, is driven onto the concrete slab. The lift arms  14  of the front-end loader  12  are at least slightly up such that the feet or support structure of the concrete hole cutting machine  10  clears the underlying concrete slab. This permits the front-end loader  12  to transport the machine from location to location about the slab. In any event, in a case where the target areas TA are aligned, the front-end loader will move, as illustrated in  FIG. 5 , down a path adjacent to the line of target areas TA. That is, the front end loader  12  will be offset with respect to the alignment of the target areas TA. As the operator of the front-end loader approaches a first target area TA he or she will align the saw  160  with the X axis of the target area. Once the front-end loader is appropriately positioned such that the saw  160  aligns with the X axis of the target area TA, then the operator will extend the second frame structure  60 . That is, control valve  234  is actuated so as to extend the rod  180 A of hydraulic cylinder  180 . This will cause the beam  120  to be extended and in the process will cause the saw  160  to be laterally shifted to the right as viewed in  FIGS. 1 and 2 . As the second frame structure  60  is laterally shifted, at some point, the saw  160  will become aligned with the Y axis of the particular target area TA. When the saw  160  becomes aligned with the Y axis then the saw  160  will be vertically aligned with the underlying target area TA. Now the operator will adjust the lift arms  14  of the front-end loader  12  causing the concrete hole cutting machine  10  to be set down on the concrete slab. In particular, the machine  10  is lowered to where the feet structure engages the concrete slab and effectively support the machine  10 . To provide additional stability, the lift arms  14  or the hydraulic controls that control the position of the adapter  20  can be caused to apply a downward force on the machine  10  so as to make the machine even more stable. 
   Once the machine  10  has been lowered into engagement with the concrete slab and the saw  160  properly aligned with the underlying target area TA, then the operator actuates the saw control valve  236 . This causes the saw  160  to rotate. Next the operator turns the spoke wheel  156  clockwise as viewed in  FIGS. 1 and 2  causing the saw  160  to be lowered into engagement with the concrete slab. Once the teeth of the saw  160  engage the slab, then operator slowly applies pressure to the spoke wheel  156  and moves the saw  160  through the concrete slab, cutting a hole H or a cylindrical chunk of concrete from the slab. Once the hole H is cut in the slab, the saw  160  is moved upwardly from engagement with the slab, and the front-end loader  12  raises the concrete hole cutting machine  10  from engagement with the slab. Now the front-end loader  12  can be moved along the path illustrated in  FIG. 5  to the next target area TA where the method is repeated. 
   There are many advantages to the concrete hole cutting machine  10  of the present invention. First and foremost it is a labor saver. By utilizing the machine  10  of the present invention, an operator can quickly and easily cut holes in a concrete slab by simply maneuvering the front-end loader from one location to another location on a concrete slab. It takes very little time to align the saw  160  with a target area TA, and once aligned, the machine can be positioned in a very stable posture such that the hole cut in the slab will be precise. 
   The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and the essential characteristics of the invention. The present embodiments are therefore to be construed in all aspects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.