Abstract:
A sheet metal bending tool for bending materials, such as flat metal sheets is disclosed. The tool has a restraining base for receiving and cooperatively holding a sheet metal workpiece and the tool has a bending component that is rotatably mounted to the restraining base, the workpiece is held, cooperating with the restraining base component, and the clamp bar for stabilizing the workpiece while the workpiece is held and bent by the rotating action of the bending component. In the preferred embodiment, the workpiece is restrained by a template comprising a pattern of holes drilled, a hole receiving a peg or means of stop, the stops (pegs) constraining the workpiece from movement while being bent act like a jig for measuring and predetermined incumbents. Holes are also drilled in restraining base and in the bending component at spaced intervals along lines that are run parallel to the line defined by the intersection of the bending component and the restraining base. There is a pull back bar that is used for the process of cutting. The Unit can be clamped down also. Rulers are installed on the clamp bar, and the slide table. The apparatus is designed so that two or more may be joined together to form a larger apparatus for the purpose of bending larger workpieces.

Description:
RELATED APPLICATIONS 
   This application is related to and derives priority from U.S. Provisional Application No. 60/376,525, entitled PORTABLE MINI-BREAK, filed May 1, 2002, which is incorporated herein by reference. 

   BACKGROUND 
   1. Field of the Invention 
   This invention relates to metal-forming and shaping tools, and more particularly to manually operable metal-bending devices of the type especially adapted to impart any of a number of predetermined shapes to metal stock, or other materials. 
   2. Current Art 
   In the past, numbers of tools for performing a variety of bending operations on metal stock have been proposed and produced, and have met with varying degrees of success. 
   However, and examination of these devices reveals several limitations of these tools; they are complex to use, expensive to make, bulky and non-portable. 
   SUMMARY 
   With the aforementioned limitations in mind, it is a general object of the invention to provide a tool for bending sheet metal, and which is simple to use and can be operated by one person. 
   It is a further object of the invention to provide a tool for bending sheet metal which is small and portable and which may be used at a variety of work locations. 
   It is yet a further object of the invention to provide a tool for bending metal and other materials and which is inexpensive to manufacture, easy to use and requires minimal skill to operate. 
   Another object of the invention is a tool for bending materials, whereby the tool may be coupled or combined with another similar tool to create a larger tool for bending materials of larger sizes. 
   And yet another object of the invention is to provide a tool for bending metal that is furnished with a template to facilitate the bending of sheet metal to a variety of angles and shapes. 
   A sheet metal bending tool is disclosed. The tool includes a restraining base for receiving and cooperatively holding a sheet metal workpiece. The tool has a bending component optionally having a second base, the bending component rotatably mounted by a hinge to the restraining base, the bending component also holding the workpiece in cooperation with the restraining base. And the tool has a stabilizing component for stabilizing the workpiece while the tool bends the workpiece. The workpiece held by the restraining base and the second base is bent by the rotating action of the bending component. 
   In the preferred embodiment, the workpiece is restrained in a desired position by at least one peg received by a hole drilled in the restraining base or by a hole drilled in the base of the bending component. Holes are drilled in the tool according to two drilling patterns: (1) holes are drilled in successive rows, each row aligned with the hinge mounting the bending component to the restraining base; and (2) holes are drilled according to a pattern, called a template, the template in the restraining base. Pegs are placed in the holes to hold the workpiece so that a certain desired bending angle can be made in the workpiece. Template holes are also drilled at a variety of angles relative to the mounting interface, so that the workpiece can be bent at a variety of angles. It will be obvious to those reading this disclosure that the pegs may be held in the drilled holes by friction alone, or both pegs and holes may be furnished with threads to permit the pegs to be screwed into the holes. 
   The tool is designed so that two or more tools can be combined to form a larger tool, which is capable of accepting and bending workpieces of larger sizes. In forming a larger tool, two or more tools are joined together, end to end. The restraining base of one tool is placed and fixed end-to-end with the restraining base of the second tool, and the base of the bending component of the first tool placed and fixed end-to-end with the base of the bending component of the second apparatus so that a larger tool surface is formed for receiving and holding larger workpieces. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1A  shows the basic arrangement of structural components of the apparatus comprising the restraining base  1100 , the bending component  1200  and the clamp arm  1500 , Also the second base called the Slide table  1400 . The restraining base and Slide table have holes drilled and fitted with pins or pegs or stops for restraining a workpiece. 
       FIG. 1B  shows the apparatus assembled and ready to accept a workpiece for bending or cutting. 
       FIG. 1C  depicts the apparatus as it appears after bending or cutting a workpiece. 
       FIG. 2A  shows the application of the apparatus to bend a flat metal workpiece, and in which the relative positions of the structural components and other components are shown while a flat metal workpiece is bent. 
       FIG. 2B  shows the application of the apparatus to bend a flat workpiece, and in which the relative positions of the restraining base, bending component and clamp arm are shown after a flat metal workpiece is bent. 
       FIG. 3A  shows the clamp arm of the apparatus in relationship to other components of the apparatus. 
       FIG. 3B  shows application of the cam handle used to clamp and hold a workpiece for bending. 
       FIG. 3C  shows the tapered edge of the clamp arm. 
       FIG. 4A  shows the handle of the apparatus withdrawn, making the apparatus ready for use. 
       FIG. 4B  is an illustration of the handle fully inserted into the apparatus, locking the components together. 
       FIG. 4C  shows the apparatus with components locked together, the apparatus ready for transport. 
       FIG. 5A  illustrates the arrangements of holes drilled in the apparatus, the holes receiving pegs or pins for restraining a workpiece, the holes drilled in a first pattern for orthogonal bending or cutting and the holes drilled according to the requirements for non-orthogonal cutting or bending patterns. 
       FIG. 5B  is a view of an exemplary arrangement of holes to receive pegs for restraining a workpiece, the pegs places so that the bending angle is an angle orthogonal to a workpiece edge. 
       FIG. 5C  is a view of an exemplary arrangement of holes to receive pegs for restraining a workpiece, the pegs places so that the bending angle is an angle not orthogonal to a workpiece edge. 
       FIG. 6A  shows a pullback bar installed on the apparatus, the pullback bar used to cut a workpiece. 
       FIG. 6B  shows the workpiece being scored prior to cutting by use of the pullback bar. 
       FIG. 6C  shows the use of the pullback bar to cut the workpiece. 
   

   DETAILED DESCRIPTION 
   With respect to  FIG. 1A , the metal bending tool  1000  comprises a restraining base  1100  for placing and cooperatively holding a sheet metal workpiece; a bending component  1200  optionally receiving and fixing in position a second base  1400 , the bending component rotatably mounted by a hinge  1300  to the restraining base  1100 , the bending component and, optionally, the second base  1400  cooperatively holding the metal workpiece in conjunction with the restraining base  1100 . The restraining base  1100  is adapted to receive a clamp arm  1500  for holding and stabilizing the workpiece while the workpiece is bent by the rotating action of the bending component  1200 . 
   The bending component  1200  has a handle  1250  that is used by an operator to bend a metal workpiece. The handle  1250  is received by a hole  1220  drilled through each handle block  1210  of the bending component  1200 . Each hole  1220  is drilled completely through the handle block  1210  so that the ends of the handle  1250  may be inserted partially into or all the way through the handle block  1210 . The handle  1250  has a plurality of holes  1280  the first hole with pin  1270  inserted is in operational use. The second hole  1280  with pin  1270  inserted places the tool  1000  in the in-operative position or the carrying position. Each handle block  1210  has a second hole  1260  for attaching the second base  1400  (the slide table) onto the bending component  1200 . The pin for holes  1260  goes to the holes on the slide arm  1410   
   The restraining base  1100  has a plurality of mounting blocks  1110 , each mounting block having a hole  1120  drilled therein. The size and placement of the mounting blocks  1110  are such that when the handle  1250  of the bending component  1200  is down each handle block  1210  aligns with a respective mounting block  1110 . When the mounting blocks  1110  are aligned with the handle blocks  1210 , the handle  1250  is inserted completely through the holes  1220  in the handle blocks  1210  and into the holes  1120  in the mounting block and locked into place by inserting the pin  1270  through the aligned holes  1280  on the Lifting Handle  1250 . In this manner the tool can be locked and easily transported. 
   While the bending operation is being performed, the apparatus  1000  can be mounted to a workbench or can be attached to legs or a stand. For that purpose mounting block  1110  is provided as part of the apparatus  1000 . It can be seen from the drawing that when the bending component  1200  and the second base called the Slide table  1400  are in a down position (the plane defined by the handle is parallel to the plane defined by the base of the restraining component  1100 ), the handle block  1210  is contiguous and aligned with the mounting block  1110 .  FIG. 1A  shows the arrangement of the handle block  1210  and the mounting block  1110  when the bending component  1200  and second base  1400  is in the down position. 
   The tool is used by: (1) positioning the bending component such that the tops of the handle blocks and the surface of the restraining base lie in a plane; (2) placing a workpiece on the surfaces of both the restraining base  1100  and the lifting bar of the bending component  1200 , and the top surface of the second base  1400  if it has been mounted in the tool, and (3) restraining the workpiece to lie flat in a fixed position on both surfaces, which are initially aligned by the hinge  1300  in a common flat plane. After the workpiece is constrained to the surface of the restraining base  1100  and the (4) the clamp bar  1500  is operated to hold the workpiece to the surfaces, by fastening the clamp bar  1500  down against the workpiece, the clamp bar  1500  attached to the restraining base  1100  by a mounting attachment  1510  on the clamp bar  1500 . (5) The bending component  1200  is operated so the second base  1400  is rotated upward. When the bending component  1200  is so operated the two surfaces no longer occupy a common plane, but now occupy two planes intersecting at an angle, the two planes intersecting along the line defined by the hinge  1300 , which is parallel to the line made by the contact of the clamp bar  1500  with the workpiece. Since the workpiece is simultaneously constrained by the clamp bar  1500  to the plane of the surfaces of the restraining base  1100  and to the plane of the second base  1400 , the workpiece is bent along the line made by the clamp bar  1500  contacting the workpiece, which is a line parallel to the hinge  1300 , and the lifting bar  1200   
   The bases of the bending component, restraining component and stabilizing components are preferably constructed from metal or from plastic or wood that is laminated with metal surfaces. 
   One example of the use of the second base occurs when a rectangular workpiece is bent according to an angle other than parallel to the edge of the workpiece. In this case the workpiece will require constraints provided by pegs placed in holes drilled in the second base. 
   With reference to  FIG. 1B  the tool  1000  is shown in an assembled form ready to receive and bend a workpiece. The restraining base  1100  is rotatably attached by the (hidden) hinge to the bending component  1200 . The handle  1250  is received and held fixed in the first hole  1220  of the handle block  1210  by the handle pin  1270 . The second base  1400  is optionally received by and held between the handle blocks  1210  by the base pin inserted into the handle block hole  1260 , the pin passing into a hole  1410  in the second base. 
   With reference to  FIG. 1B  the clamp bar  1500  is shown locked down by the cam handle  1520  having a pin or screw passing through the mounting attachment  1510  to immovably fix the clamp bar  1500  to the restraining base  1100 . It will be appreciated that in this locked position, a workpiece will be held and pressed down against the surfaces of the restraining base and the top of the bending component the Lifting Bar  1200 . If more surface area is required to support the workpiece, the second base  1400  may be inserted between, pinned and held by the handle blocks  1210 . 
   With reference to  FIG. 1C  the apparatus  1000  is shown in a position as it appears after a workpiece  1050  is bent. The workpiece is held flat to the surfaces of the restraining base  1100  also to the Slide table  1400  and the bending component  1200 . 
   Detailed Description of Operating the Metal Bending Tool 
   With respect to  FIG. 2A , the tool  2000  is operated by a person who places a metal workpiece  2050  on the flat surfaces of both the base of the bending component which could consist of the Lifting Bar  1200  FIG.  1 A and the other base the restraining base  2100 ; the tops of both surfaces lying in a single plane when the tool is ready to receive a workpiece. If more surface area is required of the bending component, the second base  2400  the slide bar can be inserted between the handle blocks of the bending component, and fixed by a pin or some other fastening means. 
   Both the slide table  2400  and the restraining base  2100  have a plurality of holes  2140 ,  2440 , each of which receive pegs or stops  2145  and  2445  for holding the workpiece  2050  in place while being bent. As previously described, holes are drilled according to two patterns, which are described in more detail below. It will be appreciated that by placing pegs in holes drilled into the bases of the bending component  2400  or the restraining component  2100 , that the workpiece will be prevented from slipping or sliding on the surface and therefore marring the fidelity or angle of the bend to be performed by the operator. 
   The workpiece is held flat against the surfaces of the bending component base  2400  and the restraining component  2100  by the clamp arm  2500 . The workpiece can be cut or bent at this point. To cut, a sharp edge is run along the face of the clamp arm  2500 . The lifting component  2200  has the slide table  2400  secured to its bases. On the slide table ends a pull back bar  2600  is connected at slots  2601 . This parallel action snaps the material at the mar. 
   With reference to  FIG. 2B  the operator of the apparatus pulls up on the handle  2250 , causing the bending component  2200  to rotate into the base of the restraining component  2100 . Since the workpiece  2050  is constrained by pins or pegs  2145  in the base of the restraining component  2100 , and by the clamp arm  2500 , the workpiece  2050  is bent by the action of the operator. 
   The bend is performed by the operator first grasping a handle  2250  attached to the handle block of the bending component  2200 , then pulling upward to cause the bending component  2200  to rotate with respect to the restraining base  2100 . The workpiece is held to the surfaces of the bending component  2200  and the restraining base  2100  by a clamp arm  2500 . By the combined restraining force exerted on the workpiece by the retraining base and the bending component and by the additional constraining action of the clamp arm  2500 , and in response to the force applied by the operator causing the bending component  2200  to rotate, the metal workpiece is bent upward. It can be seen from  FIG. 2B , that the downward force of the clamp arm  2500 , in reaction to the upward rotational force applied by the operator to the bending component, causes the workpiece to be bent upward along a line defined by the geometry or shape of the clamp arm  2500 . 
   It will be appreciated that the clamp arm  2500  contacts the workpiece along a sharp, straight line; and as a result of the geometry of contact the clamp arm causes the workpiece to be bent along a well defined and sharp or narrow line defined by the geometry or shape of the clamp arm. The stops or pegs act like jigs that are drilled holes in parts  2100  and  2400 . 
   By reference to  FIG. 2B , it can be seen that the workpiece  2050  can be bent at almost any desired angle up to approximately 120 degrees, then removed from the tool by lifting the workpiece  2050  from the surfaces of the bending component  2200  and the restraining base  2100  after loosening or removing the clamp arm  2500 . 
   An examination of  FIG. 3C  shows the clamp arm  3500  to have a tapering base  3505  that creates a knife-like edge that runs parallel to the edge of the restraining base  3100 . The knife-like edge of the tapered base  3505  of the clamp arm  3500  engages the workpiece as it is bent upward by the rotational movement of the bending component  3400 , and because of the geometry of the contact with the workpiece, causes a precise and sharp line of bending. 
   With reference to  FIG. 3A , the apparatus  3000  is shown with more detail regarding the positional relationships among the restraining base  3100 , the bending component  3200 , the slide table  3400  and the clamp arm  3500 . The clamp arm  3500  is attached by a fastening means  3550  to the base of the restraining base  3100 . 
   The manner and position of attaching is such that the an edge of the clamp arm  3500  runs parallel and flush with the edge of the restraining base  3100 . In this position, the knife-like edge of the clamp arm  3500  will engage the workpiece as the workpiece is forced upward by the rotational motion of the bending component  3400 . 
   Again with reference to  FIG. 3A  the clamp arm has a portion thereof  3510  that accepts a fastening device for the purpose of holding the clamp arm  3500  against the surface of the restraining base  3100 , and at the same time by immovably holding a workpiece flat against the restraining base  3100 . 
   In an exemplary arrangement, a pin having a cam handle  3550  is passed through the clamp arm at  3510 , and is attached to the restraining base  3100 . The pin with cam handle is made with threads, which are accepted by a properly threaded hole in the restraining base  3100 . The pin with cam handle  3550  is screwed into the threaded hole in the restraining base  3100  at both ends of the clamp arm  3500 . 
   With reference to  FIG. 3B  after a workpiece is passed under the clamp arm  3500  and laid flat on the apparatus, the cam handle  3550  is lifted up and due to the action of the cam the clamp arm  3500  is forced downward to cause the workpiece to be held tight against the surface of the bending tool. 
   With reference to  FIG. 4A , the tool  4000  is shown with the handle  4250  withdrawn from the handle blocks  4210 , whereby the tool is ready for use. 
   With reference to  FIG. 4B  the tool is shown with the handle  4250  inserted into the handle blocks  4210 , and further into the mounting blocks  1110  of the restraining base  1100  as shown in FIG.  1 A. When the handle  4250  is inserted into the mounting blocks of the restraining base, the handle can be fixed in this position by a pin or peg that passes through a hole drilled in the handle block  4210 , the hole aligned with a similar hole in the handle  4250 . 
   With reference to  FIG. 4C , the tool is shown with the handle  4250  inserted and held by a peg or pin. In this arrangement, the tool can be carried about or transported. 
   Patterns of Holes and Pegs to Hold the Workpiece 
   A workpiece is held in the tool by placing the workpiece on the surface of the tool, then placing pegs in the appropriate holes. If complex bending angles are required the template is used. Complex bending angles comprise the set of angles that are not parallel or perpendicular to an edge of the workpiece. 
   Tool Template 
   With reference to  FIG. 5A  the template has holes  5140  made in the restraining base  5100 ; the template  5140  having a pattern of holes drilled in the form of a protractor, the protractor for the purpose of positioning a workpiece so that a bend can be made that is not parallel to workpiece edge pinned on the restraining base  5100 . 
   It will be appreciated that several arrangements of holes in the template  5140  can be made to provide a variety of bending angles ranging from 20° to 90° in increments of 5°, 10°, for example. It will also be appreciated that the template  5140  can be formed separately and inserted into or fastened to the surface of the bending component or the surface of the restraining component using any well-known fastening or holding means.  FIG. 5A  also displays the working storage position  5160  where the stops are placed when not in use. The carrying storage position for the stops is under the slide table placed in the bending component  1200  FIG.  1 A. 
   With reference to  FIG. 5B , the tool is shown with a workpiece  5050  that has been passed under the clamp arm  5500 . The workpiece  5050  is shown flush against two pegs  5145  that have been placed in holes of the template. In this case, the holes have been selected so that the bend (along the knife edge of the clamp arm  5500 ) will be orthogonal to edges of the workpiece  5050 . While in this position, the cam handle will be operated to clamp the workpiece  5050  down against the surface of the tool so that the desire bend can be made. 
   With reference to  FIG. 5C , the pegs  5150  have set into holes along the lines of the template protractor so that a non-orthogonal bend can be made. 
   It will be appreciated that from the description given, the tool can be easily and economically made, and can be operated by a single person. The apparatus is compact and, therefore, can be easily transported from place to place. 
   Using the Tool to Cut a Workpiece 
   With reference to  FIGS. 6A ,  6 B and  6 C the tool is shown equipped with a pullback bar  6600 . 
   With reference to  FIG. 6A  the pullback bar  6600  is removably attached to the bending component  6400 , whereby a workpiece  6050  is placed under the pullback bar  6600 , and is then prepared for bending as previously described. 
   With reference to  FIG. 6B , the workpiece  6050  is scored with a sharp or pointed instrument. 
   With reference to  FIG. 6C , the bending component  6400  is operated by moving the bending component  6400  up and down repeatedly. It can be seen that the pullback bar  6600  causes the workpiece  6050  to be constrained to the surface of the bending component  6400  during the repeated up and down motion. It will be appreciated that after several iterations of up and down bending, the workpiece  6050  will separate cleanly, in a cut, along the line scored. 
   SUMMARY OF THE DISCLOSURE 
   The tool has been described and depicted through drawings with typical components and arrangements. It will be appreciated that other variations in component size, capacity and arrangement are possible and will be obvious in view of the preceding disclosure. 
   Therefore the scope and limitation of the present invention are most suitably provided though and by the following claims.