Abstract:
An automatic hoop forming machine comprising a wire decoiling and feeding element connected to a series of rollers designed to pull, take out some irregularities and partially impart a curve before said wire is fed on to a hoop guide roll of the desired diameter to form a hoop-shaped element. The ends are overlapped and welded prior to cutting. Any number of hoops may be formed automatically and are eminently useful as reinforcing members within cementitious materials used to make manholes, for example.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention:  
         [0002]     This invention relates to the field of the reinforcement of concrete and other cementitious materials or mixed cementitious materials. More specifically, this invention relates to the reinforcement of cementitious elements such as, for example, manhole elements such as risers, conical tops and grade rings therefore. Still more specifically, this invention relates to circular or hoop shaped circumferential reinforcing elements for such manhole risers, conical tops and grade rings (hereafter called “manhole elements”) therefore and to a unique and automated method for making such hoop shaped circumferential reinforcing elements.  
         [0003]     2. Description of the Prior Art:  
         [0004]     Manhole elements are used within the industry to provide access to drains such as sewers or storm water drains. These manhole elements conventionally comprise a series of cementitious sections that interlock and come up from under the ground and eventually exit through a manhole cover to the street or other ground level. These sections are conventionally manufactured from concrete or other mixed cementitious materials and it is requisite that these materials of manufacture be reinforced in order to provide utility and safety during the handling thereof. By concrete I mean cementitious materials or mixtures thereof. Conventionally, these reinforcing elements have been metal mesh elements conventionally made from steel. These mesh elements are placed within the mold prior to the introduction of the unhardened cementitious materials and when these cementitious materials cure and harden, the product is strengthened by the presence of these reinforcing elements. The problem is that such steel mesh is expensive to make and to use and there has been an on-going attempt to reduce the cost of the manufacture of the cementitious elements for manhole construction.  
         [0005]     Recently, steel, hoop shaped reinforcing elements have been introduced in an effort to save the costs of using steel mesh. These hoops can be placed at strategic areas within the concrete during the manufacture and can provide acceptable reinforcing characteristics. Such a process and the placement of such reinforcing hoop shaped elements are described in ASTM C-478. These hoop shaped circumferential reinforcing elements can be hand made by using a mandrel of the appropriate size and bending the reinforcing rod or wire around the mandrel prior to welding in place to form the hoop. Another process is to make a series of interconnected hoops of the desired size to form a spring like element. Then, individual hoops are made by cutting this element in appropriate spots into pieces and welding each piece to form the hoop. Used in this manner, these steel hoops provide circumferential reinforcement of manhole elements and the like.  
         [0006]     Of course, the problem with the above is that it is more labor intensive and hence also costly and there has been a pressing need to have something that will manufacture these reinforcing hoops automatically in order to save the additional labor costs.  
       SUMMARY OF THE INVENTION  
       [0007]     It is an object of this invention to provide steel reinforcing hoops that can be used to reinforce cementitious materials. It is also an object of this invention to provide such reinforcing hoops that can be used within cementitious manhole elements such as risers and the like. It is a further object of this invention to provide a machine that can automatically manufacture such reinforcing hoops. These and yet other objects are achieved in an automatic and continuous hoop forming machine comprising components in order,  
         [0008]     a. a coil of steel wire located on a wire decoiling device;  
         [0009]     b. a primary series of automatic opposed wheels designed such that as said steel wire is passed between said opposed wheels, irregularities in said steel wire are removed and said steel wire is directed in the next component of said machine;  
         [0010]     c. a secondary series of automatic opposed wheels designed such that as said steel wire passes between said secondary series of opposed wheels further irregularities in said steel wire are removed and said steel wire is further straightened and directed in the next component of said machine;  
         [0011]     d. a third series of automatic opposed wheels designed to feed said steel wire by pulling from said secondary opposed wheels and directing said steel wire into the next component of said machine;  
         [0012]     e. a fourth series of automatic opposed wheels designed to form a nominal radius into said steel wire and direct said steel wire into the next component of said machine;  
         [0013]     f. a movable and specifically sized circumferential wheel designed to bend said steel wire into a hoop shaped element;  
         [0014]     g. an automatic welder for joining said hoop shaped element;  
         [0015]     h. a cutting device designed to shear said steel wire when said hoop shaped shape element is formed and welded, and  
         [0016]     i. a device to hold a plurality of said hoop shaped elements as formed, welded and sheared.  
         [0017]     In yet another embodiment the objects of this invention are achieved in a process for the automatic manufacture of steel reinforcing hoops wherein a coil of steel wire is fed from a decoiling device by pulling using a set of opposing rollers, through a second set of opposing rollers to straighten and remove any curve therein, through and around a specifically sized circular wheel to form a hoop form thereby, followed by welding said wire and cutting said wire ends proximate to said welding whereby a hoop is formed.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  is a cutaway view showing of a typical manhole installation in which the steel reinforcing hoop shaped elements of this invention are particularly useful.  
         [0019]      FIG. 2  is a full, perspective view of the front of a particularly preferred machine useful within the metes and bounds of my invention.  
         [0020]      FIG. 3  is another more detailed view of  FIG. 2 .  
         [0021]      FIG. 3A  is a detailed and enlarged drawing of the mechanism for shearing the wire and welding the elements thereof.  
         [0022]      FIG. 4  is a detailed view of the rear of  FIG. 2 .  
         [0023]      FIG. 5  shows a reinforcing hoop after being formed by the machine of this invention.  
         [0024]      FIG. 6  shows metal wire being fed to the device shown in  FIGS. 1-4  and contained within the turntable decoiling feeding device. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]     Looking now specifically at the drawings accompanying this invention, which show particularly preferred embodiments, but to which I am not limited,  FIG. 1  is a cutaway view of a typical manhole the components of which may contain the reinforcing hoops of this invention. In this drawing, going from top to bottom, or from ground level to under ground level, I is the grade ring having an opening  2  through which one can enter the manhole.  3  is an eccentric cone top followed by two riser sections  4  and  5 , which are shown as different lengths (2′ and 4′) in this drawing.  6  is a 4′ extended base section with a foot  7  to permit a firm footing under ground. The connection and mating elements of each section are shown as  8 ,  8   a  and  8   b.  A series of entry steps, one of which is shown as  9 , permit easy entry into the manhole for servicing. One, of what may be a plurality of pipe openings, is shown as  10 . The reinforcing hoop elements made by the teachings of this invention are useful in forming the various cementitious parts of this manhole according to ASTM C-478 and would then reinforce this entire manhole, for example.  
         [0026]      FIG. 2  is a full, front and perspective view of the machine for making the hoop elements of this invention. In this  FIG. 11  is a turntable base holding a turntable that further holds a coil rack  12  designed to hold a coil of wire (not shown). The wire coil is held down in place by an adjustable and removable coil clamp down guard  13  that is anchored down into a decoiling turntable  14 . From thence, the wire is fed into a lead-in roll set  15  designed to control entry of the wire into the machine. From there the wire is fed into a straightening roll set  16  and then an automatic roll set  36  which pulls the wire from thence and feeds further. A radius roll set  17  bends the wire to an initial radius prior to moving on to the hoop forming guide roll  18 . In this particular embodiment a 53″ guide roll is shown. A 30″ guide roll is shown as  19  and this can be substituted for the 53″ guide roll by tilting the 53″ guide roll to a horizontal position on its guide storage arm  20 , swinging it to a storage position and, in a reverse manner, replacing it with the 30″ guide roll  19 . As the hoop is formed inside the desired guide roll, the end comes down to a weld/shear area  21 . At this point, the wire is welded and cut automatically and the individual hoop can be moved onto a hoop handling device  22 . This device can hold a number of hoops as they are formed. Since this device is on rollers, the device can be moved to another location to permit convenient access to individual hoops to be located within the concrete or cementitious material being used to form a manhole, for example. Additionally, the device is designed to be handled by other means commonly available in the industry. For example, lifting eyes may be provided to facilitate moving by means of an overhead crane, for example. Also, the base of the device is designed to facilitate safe and convenient handling by means of a fork truck. Alternatively, the device is designed so that all the hoops being stored on the device may be removed, in bulk, directly from the device by means of a fork truck. An electrical and computer control box is shown as  23 . This control box houses and protects various electrical and automation components. A computer control panel mounted on the box provides access to the individual machine functions and control of the automated functions and computer parameter settings of the machine. For example, the user may enter by means of the computer control panel the number of hoops required for any particular need. A weld shielding gas container is shown as  24 .  
         [0027]      FIG. 3  is another, more detailed view of  FIG. 2  in which all of the components listed thereon are shown here. Added to this figure is a turntable spin control strap  25 . This applies some tension to the wire decoiling element so that the decoiling action is appropriately controlled. Also shown is an arc welding element  26 .  
         [0028]     Looking now at  FIG. 3A , this is a detailed and larger view of the mechanism for shearing the wire and welding in order to form the requisite hoop therefrom. This view is an enlargement of the element shown as  21  on  FIG. 3  following the line A-B. In this figure, one of the guide roll clamps is shown as  27  and the shear element as  28 . After the wire (not shown) is fed through and around the hoop guide roll (either  18  or  19 ) it will travel through the weld/shear area  21 , overlapping and stopping at an appropriate and desired length of overlap. The leading end conventionally overlaps on top of the trailing end and a weld is automatically placed at this point (see  FIG. 5  for details). After welding, the shear knife will be moved forward to cut the trailing end of the wire and ejects the finished hoop from the weld/shear area  21 . The welding automatically occurs behind the area marked as  29 .  
         [0029]      FIG. 4  is a detailed view from the rear of  FIG. 2  where all the elements are numbered as shown in  FIGS. 1-3 . Additional elements that can be seen in this figure include a hydraulic power unit  30  and the hydraulic control valves  31 .  
         [0030]      FIG. 5  is a showing of a typical steel hoop reinforcing element made by the machine described in this invention. Here the hoop is shown as  32  and the weld joining the ends as  33 . One can clearly see (looking at the enlarged detailed view in the figure) that the ends of the hoop are conventionally overlapped prior to welding in order to ensure strength and rigidity and that the weld is between the overlapped ends of the hoop.  
         [0031]      FIG. 6  is identical to  FIG. 2  except that a roll of wire  34  is being stored on coil rack  12  which is anchored to the decoiling turntable  14  mounted on turntable base  11 . The actual wire itself  35  is also being shown fed into lead-in roller set  15 , then straightening roller set  36  which then feeds the wire into the machine for automatically making the requisite hoop.  
         [0032]     Conventionally my machine can be programmed to make as many reinforcing hoops as desired in a consistent and accurate method. Hoops of any reasonable size can be made but the usual sizes run from 30″ to 53″ in diameter. Hoop guide rolls of varying sizes can be kept on the machine and moved and changed quickly and conveniently as the manufacturing process requires. The manufacture of these hoops is quick and the machine can output 400 to 600 hoops per hour greatly satisfying the requirement to save man hours and yet produce a superior reinforcing material for the manufacture of cementitious products such as those used in the manufacture of manholes. I envision that these hoops can also be used in the manufacture of cementitious or mixed cementitious elements such as large drain pipes and the like.  
         [0033]     The process is fairly straightforward, convenient and highly automated. A coil of industrial grade wire typically Grade 60, High Carbon material of about 0.250″ in diameter is conventionally supplied on the wire coil rack shown as  12  in the drawings. The wire coil rack is placed on and anchored to the decoiling turntable  14 . The end of this wire is fed into the lead-in roll set  15 . From there, the end of the wire enters the straightening roll set  16  and further into the automatic roll set  36 . The end of the wire is then fed through the radius roll set  17 . Next, the end passes through the weld/shear device  21  and up, over and through the guide roll either  18 ,  19  or other size, depending on the requisite size of the hoop needed. When the end reaches the weld/shear device again, the automation program detects this event and stops the feeding of the wire at the correct and desired overlap. The program then initiates the welding of the wire at this area of overlap to join the ends together as shown in  FIG. 5 . As hoops are made, a few can be kept on the guide roll but as it becomes full, hoops are dropped off on to a hoop handling device,  22 , where more than a few can be kept in a storage mode. The entire process is automated and controlled by computer control box  23  and driven by hydraulic power unit  30 . Welding is accomplished using a MIG Welding Machine shown as  26 , for example. However, any conventional welding system that uses the molten metal “puddle” effect can be used. The “puddle” must be protected or shielded from oxygen in the atmosphere, otherwise the metal will “burn” resulting in porosity and a very poor weld. In the MIG (Metal Inert Gas) process, this is accomplished by blowing an inert gas such as argon or carbon dioxide at the weld area. This shielding gas is shown as  24 . Changing sizes is easy and simple, requiring only the movement of a few interconnected elements to move one hoop guide up and into a storage position and the other into the working position. Each part of my device can be made to interconnect with the other to ensure ease of use. For example, the element containing the wire to be fed from a coil can be unattached from the machine unit so that installing more coil wire is made easily. The storage rack holding the hoops already made can be placed on rollers so that when the requisite hoops have been manufactured, they can be rolled over to the station where the cementitious elements are being made to be incorporated therein.