Abstract:
A hydraulically rebar bender for skid-steer loader includes a structural case with quick-attach flanges for attachment to skid-steer loaders. The case has an adjustable work tray mounted on the face for supporting the rebar when bending. One end of a hydraulic cylinder is connected to the case and a distal end is connected to a rack gear. The rack gear mates with a pinion gear that is mounted on an axle. The pinion gear is connected to a bending disc that rotates with the pinion gear. A force shaft is mounted on the bending disk. The force shaft travels in a circular cutout of the case and accepts various size mandrels. The axle protrudes out of the case and has a bend mandrel mounted thereon. Hydraulic power is supplied by the skid-steer loaders hydraulic system via hydraulic supply hoses.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional patent application Ser. No. 60/937,140 filed 2007 Jun. 27 by present inventor. 
    
    
     FEDERALLY SPONSORED RESEARCH 
     Not Applicable 
     SEQUENCE LISTING OR PROGRAM 
     Not Applicable 
     BACKGROUND OF INVENTION 
     1. Field of Invention 
     This invention generally relates to the bending and forming of metal rods and bars, especially concrete reinforcement bars (rebar) at a construction job site. 
     2. Prior Art 
     Concrete reinforcement bar, hereafter referred to as rebar, has been used in construction for many years. Rebar is produced in straight pieces of varying lengths, sometimes up to 40 feet. Rebar needs to be bent before being placed for various reasons such as foundation corners, column “cages” and the like. Until recently, job site bending and cutting was done with a manual tool or machine such as the one invented by Tolman, U.S. Pat. No. 6,418,773 B1. Currently there are several attempts at providing a means to bend and cut rebar on the job site, these include table mounted electrically powered machines, trailer mounted hydraulic and electrically powered machines, small handheld machines, and one known loader mounted hydraulically powered machine invented by Brown, U.S. Pat. No. 5,878,615. 
     Because of the extreme weight and awkwardness of rebar and the normally rough job site terrain, table top machines are not stable enough to efficiently perform. Handheld machines are not designed for larger size rebar or production bending and cutting. Both table top and handheld machines require either electrical power, a external hydraulic power source, or both. Trailer towed machines lack the ability to access areas that skid steer loaders do either for job site space constraints or terrain features. 
     Because of their great power, all-terrain ability and the versatility of quickly adding and changing a variety of attachments, skid-steer loaders have become common in the construction industry. Most skid-steer loaders are manufactured with hydraulic connections at the end of the lift arms enabling attachments that require hydraulic power to be used. This all-terrain hydraulic power source coupled with the stable work platform provided by the loaders heavy weight and low profile make my hydraulic rebar bender cutter attachment for skid-steer loader the preferred tool for jobsite metal bending and cutting. 
     Browns device though capable of being attached to a loader vehicle lacks the ability to bend beyond approximately 90 degrees. This is a major limitation since bends of up to 180 degrees are common in the industry. Additionally, although he claims his invention requires only one hydraulic cylinder to perform, it actually has two separate hydraulic cylinders with an accompanied sequencing valve, complicating the process. Therefore a need remains for a simple, reliable, loader mounted rebar bending and cutting attachment that is capable of production bends of up to 180 degrees without repositioning the rebar. 
     SUMMARY 
     In accordance with one embodiment, a rebar bender cutter machine that is:
         (A) Hydraulically powered.   (B) Capable of bending up to 180 degrees without repositioning the rebar.   (C) Capable of cutting metal rods and bars.   (D) Capable of attaching to a skid-steer loaders standard quick-attach mounts.   (E) Gear driven.   (F) Durable and reliable.   (G) Efficient to build.       

     These and other objectives will be achieved by providing a device in the preferred embodiment with a rack and pinion gear system. One end of the rack is connected to a hydraulic cylinder that is actuated by an actuating means. The other end of said hydraulic cylinder is mounted to the machines case, which is an integral frame and housing for the components. The rack gear travels laterally in a slide channel. The rack gear is mated to a pinion gear that rotates freely on a fixed axel. A small portion of said fixed axel protrudes through the front of said case and acts as a bend shaft for mounting a bend mandrel. The opposite end of said fixed axel is mounted in an axle flange on the back case cover. Because different size rebar require different size bends, there is an assortment of mandrel sizes to accommodate industry standard minimum bend radii. 
     Attached to the pinion gear is a larger round bending disc. The bending disc rotates freely on said fixed axel and in unison with the pinion gear. Attached toward the outer edge and perpendicular to the face plane of the bending disc is a force shaft. The force shaft is a short axel that accepts a mandrel. The force shaft is of the same diameter as the bend shaft so as to allow the mandrels to be interchanged. The force shaft protrudes through the front of the case and travels in circular cutout. Attached to the front of the case is an adjustable work tray for supporting and positioning the rebar during bending. The work tray can be raised or lowered to the proper position to accommodate the different size mandrels and rebar. 
     Attached to the end of the rack gear opposite of the end of the hydraulic ram attachment is a cutter blade. When the hydraulic ram is fully extended the cutter blade attached to the rack gear contacts another cutter blade mounted on the far end of the slide channel. The case provides protection for the cutting blades. A U-shaped channel is cut out of the case perpendicular to the cutting blades linear travel. This channel is referred to as the “cutting-zone”. When a piece of rebar is inserted into the cutting zone and the machine is activated the rebar will be cut when the hydraulic ram reaches its full length of travel and the cutter blades meet. 
     To bend, install the proper size mandrel on the bend shaft and the force shaft. Set the work tray to the proper height. Place the rebar on said work tray. Position the rebar laterally so as the desired bend point is under the bend mandrel. When the machine is activated, hydraulic power from the skid-steer loader causes the hydraulic ram to extend, further causing the rack gear to move in parallel with the hydraulic ram. The rack gear causes the pinion gear and the bending disc to rotate causing the rebar to bend. 
     Mounted on the back of the case are industry standard attachment flanges for skid-steer loaders. The attachment flanges are commonly referred to as quick-attach flanges. Mounted on the bottom of the case are two U-channels that will accept fork lift style forks. The U-channels also act as feet to keep the machine off the ground when not attached to the skid-steer loader. 
    
    
     
       DRAWINGS 
       Figures 
         FIG. 1  is an isometric front view with the control switch attached. A piece of rebar is inserted and ready to bend. 
         FIG. 2  is an isometric back view with the case, rear cover, work tray and quick-attach flanges removed for better viewing of the internal parts. 
         FIG. 3  is an exploded view of the internal parts. For clarity the case, rear cover, work tray, quick-attach flanges, electrical and hydraulics are not displayed. 
         FIG. 4  shows the machine with a piece of rebar positioned on the work tray and bent 90 degrees. The control switch is unplugged and not shown. 
         FIG. 5  shows the machine with a piece of rebar positioned on the work tray and bent 180 degrees. The control switch is unplugged and not shown. 
         FIG. 6  shows the machine with a piece of rebar inserted in the cutting-zone and ready to be cut. 
         FIG. 7  shows the machine with a piece of rebar inserted in the cutting-zone and cut. 
         FIG. 8  shows an exploded view of the case and work tray components. 
         FIG. 9  shows a rear isometric view of the work tray for viewing of the adjustment pins. 
       
         
           
                 
               
                 
                 
                 
                 
               
             
                 
                     
                 
                 
                   DRAWINGS—REFERENCE NUMBERALS 
                 
                 
                     
                 
               
               
                 
                     
                 
               
            
             
                 
                     
                     
                   11 
                   Rebar 
                 
                 
                     
                     
                   12 
                   Fixed Axle 
                 
                 
                     
                     
                   13 
                   Bend Mandrel 
                 
                 
                     
                     
                   14 
                   Retaining Washers 
                 
                 
                     
                     
                   15 
                   Retaining Bolt 
                 
                 
                     
                     
                   16 
                   Force Mandrel 
                 
                 
                     
                     
                   17 
                   Circular Cut-out 
                 
                 
                     
                     
                   18 
                   Cutting Zone 
                 
                 
                     
                     
                   19 
                   Work Tray 
                 
                 
                     
                     
                   20 
                   Adjustment Bolt 
                 
                 
                     
                     
                   21 
                   Fork Channels 
                 
                 
                     
                     
                   22 
                   Case 
                 
                 
                     
                     
                   23 
                   Hydraulic Cylinder 
                 
                 
                     
                     
                   24 
                   Hydraulic Manifold 
                 
                 
                     
                     
                   25 
                   Hydraulic Ram 
                 
                 
                     
                     
                   26 
                   Slide-Bar Rack Gear Assembly 
                 
                 
                     
                     
                   27 
                   Bending Disc 
                 
                 
                     
                     
                   28 
                   Pinion Gear 
                 
                 
                     
                     
                   29 
                   Cutter Blades 
                 
                 
                     
                     
                   30 
                   Slide Channel 
                 
                 
                     
                     
                   31 
                   Quick Attach Flanges 
                 
                 
                     
                     
                   32 
                   Hydraulic Supply Hoses 
                 
                 
                     
                     
                   33 
                   Force Shaft 
                 
                 
                     
                     
                   34 
                   Adjustment Holes 
                 
                 
                     
                     
                   35 
                   Adjustment Pins 
                 
                 
                     
                     
                   36 
                   Control Switch 
                 
                 
                     
                     
                   37 
                   Adjustment Knob 
                 
                 
                     
                     
                   38 
                   Control Switch Receptacle 
                 
                 
                     
                     
                   39 
                   Power Supply Cord 
                 
                 
                     
                     
                   40 
                   Bend Shaft 
                 
                 
                     
                     
                   41 
                   Hydraulic Control Valve 
                 
                 
                     
                     
                   42 
                   Axle Flange 
                 
                 
                     
                     
                   43 
                   Adjustment Slot 
                 
                 
                     
                     
                 
               
            
           
         
       
     
    
    
     DETAILED DESCRIPTION 
     Preferred Embodiment—FIGS.  1 ,  2 ,  3 ,  8 ,  9   
     The primary purpose of this machine is to bend and cut concrete reinforcement bar commonly known as “Rebar”. For the purpose of these specifications and this preferred embodiment the term “Rebar” will be used throughout. This is not to limit the scope to only rebar since the machines design favors bending any kind of plastically deformable material that is elongated in shape. In addition, the preferred embodiment of the machine is to be mounted and hydraulically powered by a “skid-steer” loader vehicle. For the purposes of these specifications the term “skid-steer” will be used throughout. This is not to limit the scope of the machine to skid-steer loaders since by design it is capable of being mounted and powered by any type of loader vehicle with a hydraulic power source of sufficient output to operate the machine, such as backhoes, tractors, articulating loaders, forklifts and the like. 
     The machine is comprised of a hydraulic cylinder  23  attached to a case  22  on the cylinder end, and to a rack gear slide-bar assembly  26  on the hydraulic ram  25  end. The slide-bar rack gear assembly  26  travels laterally through a slide channel  30 . The purpose of the slide channel  30  is to guide the slide-bar rack gear assembly  26  as it travels back and forth. A pinion gear  28  is free mounted on a fixed axel  12  in such a manner that it engages the slide-bar rack gear assembly  26 . When the hydraulic cylinder  23  is powered the slide-bar rack gear assembly  26  moves laterally causing the pinion gear  18  to turn proportionally. A bending disc  27  is connected to the pinion gear  28  and mounted on the common fixed axel  12  so as to turn in unison with the pinion gear  28 . Both the pinion gear  28  and the bending disc  27  rotate freely on the fixed axel  12 . The fixed axel  12  penetrates the front face of the case  22  and acts as a mounting shaft for various size mandrels. The portion of the fixed axle  12  that protrudes outside the front of the case  22  will be identified as the bend shaft  40 . 
     The bending disc  27  has a force shaft  33  mounted toward the outside edge and perpendicular to its face. Said force shaft travels in a circular cut-out  17  in the face of the case  22 . The force shaft  33  is of the same diameter as the bend shaft  40  so as to allow mandrels to be interchanged. The mandrels here forward will be called the force mandrel  16  when installed on the force shaft  33  and the bend mandrel  13  when installed on the bend shaft  40 . The force mandrel  13  and the bend mandrel  16  vary in size to accommodate industry standard minimum bend radii. The fixed axel  12  is fixed in position so as not to rotate when the pinion gear  28  and the bending disc  27  rotate. 
     The force shaft  33  is fixed in position so as not to turn. The force shaft  33  has a shoulder to keep the force mandrel  13  from contacting the face of the case  22  when it is installed. The end of the force shaft  33  is drilled and tapped to accept a retaining bolt  15  and retaining washer  14 . The retaining bolt  15  and retaining washer  14  prevent the force mandrel  16  from coming off the force shaft  33 . The length of the force shaft  33  is such that when the retaining bolt  15  and the retaining washer  14  is installed and tightened the force mandrel  16  can rotate freely. This allows the force mandrel  16  to roll over the rebar  1  and around the bend mandrel  13  as the machine is working. 
     Mounted on the face of the case  22  is an adjustable work tray  19  used to position and support the rebar  1  while bending. The work tray  19  has two adjustment pins  35  mounted on the face that contacts the case  12 . The adjustment pins  35  are positioned towards the ends of the work tray  19 . The case  22  has a series of adjustment holes  34  positioned horizontally so as to line up with the work tray  19  adjustment pins  35 . The adjustment holes  34  are positioned vertically at a height on the case  22  so as to allow the work tray  19  to be positioned the proper increment up or down according to the rebar  11  size. The adjustment holes  34  are also positioned vertically at an angle so as to move the work tray  19  horizontally closer to the bend mandrel  13  when smaller sizes are installed thereby keeping a uniform distance between the bend mandrel  13  and the end of the work table  19 . The work table  19  is secured to the case  22  with an adjustment bolt  20  and an adjustment knob  37 . The adjustment bolt  20  is allowed to travel vertically in an adjustment slot  43  cut in the case  22 . The adjustment slot  43  is cut at the same angle as the adjustment holes  34 . To adjust the height of the work tray  19  simply loosen the adjustment knob  37  to allow the enough space between the case  22  and the work tray  19  to disengage the adjustment pins  35  from the adjustment holes  34 . Position the work tray  19  to the desired level by lining up the adjustment pins  35  with the adjustment holes  34  and tighten the adjustment knob  37 . 
     The bend shaft  40  is drilled and tapped to accept a retaining bolt  15  and retaining washer  14 . The purpose of the retaining bolt  15  and retaining washer  14  are to secure the bend mandrel  13  on the bend shaft  40 . The length of the bend shaft  40  is slightly shorter than the bend mandrels  13  depth. When the bend mandrels  13  retaining bolt  15  and retaining washer  14  is installed and tightened the bend mandrel  13  will be drawn snuggly against the front of the case  22  thereby preventing it from rotating. This keeps the rebar  11  from rolling forward when bending. 
     The hydraulic cylinders  23  fluid and pressure is supplied by the skid-steer loader through hydraulic hoses  32  with industry standard quick-connect fittings. When the hydraulic supply hoses  32  are connected to the skid-steer, hydraulic pressure flows through the hydraulic supply hoses  32  to the hydraulic manifold  24 . An electric solenoid hydraulic control valve  41  mounted in the hydraulic manifold  24  controls the flow of hydraulic fluid from the hydraulic manifold  24  to the hydraulic cylinder  23 . The hydraulic control valve  41  is powered from the skid-steer loaders electric system by connecting the machines power supply cord  39  to the skid-steer loaders power receptacle mounted on the boom. 
     Actuation of the hydraulic control valve  41  is accomplished by an actuation device such as a foot pedal or a hand selector switch. In an alternate embodiment the hydraulics could be controlled by a manual spool valve. In addition, programmable logic controllers could be incorporated for automation. From here forward we will refer to the actuating device as a control switch  36 . 
     OPERATION 
     Preferred Embodiment—FIGS.  4 ,  5 ,  6 ,  7 ,  8 ,  9   
     To operate the Hydraulic Bender Cutter machine in the preferred embodiment attach the machine by maneuvering the skid-steer loader so as the loaders mounting plates engage the quick-attach flanges  31  on the back of the machines case  22 . Attach the hydraulic supply hoses  32  to the skid-steers hydraulic quick-connect fittings. Raise and tilt the machine to the desired work height and angle. 
     Install the proper size force mandrel  16  on said force shaft and secure the force mandrel  16  by installing the retaining washer  14  and the retaining bolt  15  in the tapped hole in the force shaft  33 . Install the proper size bend mandrel  13  on the bend shaft  40  and secure the bend mandrel  13  by installing the retaining washer  14  and the retaining bolt  15  in the tapped hole in the bend shaft  40 . 
     Adjust the height of the work tray  19  by loosening the adjustment knob  37  to allow enough space between the case  22  and the work tray  19  to disengage the adjustment pins  35  from the adjustment holes  34 . Position the work tray  19  to the desired level by lining up the adjustment pins  35  with the adjustment holes  34  and tighten the adjustment knob  37 . 
     Place the rebar  11  on the work tray  19  and position the rebar  11  laterally so that the desired bend point is under the bend mandrel  13 . Multiple rebar  11  can be bent simultaneously by stacking the bars flat on the work tray. When ready to bend, activate the control switch  36  in the bend direction. Release the control switch  36  when the bend has reached the desired angle. Return the force mandrel  16  to the start position by activating the control switch  36  in the return direction. 
     For cutting, with the hydraulic cylinder  23  in the retracted position, simply place the rebar  11  in the cutting zone  18  and activate the control switch  36  as if bending. When the cutter blades  29  meet, the rebar  11  will be cut. To open the cutter blades  29  for another cut, simply activate the control switch  36  in the return direction until the cutting zone  18  is clear. 
     CONCLUSION, RAMIFICATIONS, AND SCOPE 
     Accordingly the reader will see that, according to one embodiment of the rebar bender cutter for skid-steer loader, I have provided a simple, durable and reliable rebar bending and cutting attachment. When the rebar bender cutter attachment is installed on a skid-steer loader, it is capable of being positioned as desired around a job site regardless of terrain conditions. Once at the desired work spot the operator can position the rebar bender cutter to the optimum work height and angle for less operator fatigue and greater comfort. In addition, the great weight of the skid-steer loader provides for a very stable work platform. 
     Because of the machines simple and durable construction it can be stored outside with other typical skid-steer loader attachments requiring less care than other known benders. 
     While the above description contains many specificities, these should not be construed as limitations on the scope of any embodiment, but as exemplifications of the presently preferred embodiments thereof. Many other ramifications and variations are possible within the teachings of the various embodiments. For example, a hydraulic motor with reduction gearing could be employed rather than a rack and pinion system. 
     Thus the scope of the invention should be determined by the appended claims and their legal equivalents, and not the examples given.