Rocker and platform assembly for self-dumping hoppers and the like
United States Patent [1 1 Quinn et al.  
 [ Apr. 22, 1975 [75] inventors: Lawrence R. Quinn, Bloomfield Hills; Max J. Bielenberg, Detroit,  
 both of Mich.  
 [73] Assignee: Roura Iron Works, Inc., Detroit,  
 Mich.  
 [22] Filed: Aug. 2, 1973 21 Appl. No.: 385,216  
  Related US. Application Data [62] Division of Scr. No. 264.652, June 20. 1972, Pat. No.  
 [52] US. Cl. 214/130 R; 72/335 [51] Int. Cl. B66C 23/00 [58] Field of Search 214/130 R; 72/324, 327, 72/332, 333, 336, 335  
 [56] References Cited UNITED STATES PATENTS l.623,325 4/l927 Wetmorc 4. 72/327 2,519,153 8/l950 Roura 2l4/l30 R 2.848.805 8/[958 Brink 72/324 3,494,168 2/l970 Williamson 72/335 3.507.140 4/l970 Tassaro 72/327 Primary liraminer-Robert J. Spar Assistant Eruminer-Kenneth Noland AIIOI&#39;HP). Agent, or Firm-Reising, Ethington &amp; Perry [57] ABSTRACT Hole forming apparatus comprising a punch having a cutting portion at its leading end for cutting and punching a hole in a metal sheet, and a forming portion following said cutting portion for shaping the material of the metal sheet surrounding the hole, the cutting portion comprises a cutter extending from the leading end of the punch and the forming portion in cludes a flared section providing a material deforming shoulder. a cylindrical section having a greater lateral dimension than the cutter, and an outwardly radiused section, and a die which cooperates with the punch for shaping the material of the metal sheet surrounding the hole. Also disclosed is a tooth guided rocker and platform assembly for self dumping hoppers and the like wherein the teeth of the rockers are guided into and out of holes formed by the hole forming apparatus.  
 2 Claims, 5 Drawing Figures ROCKER AND PLATFORM ASSEMBLY FOR SELF-DUMPING HOPPERS AND THE LIKE This application is a divisional of application Ser. No. 264,652, filed June 20, 1972, now US. Pat. No. 3,776,016 issued Dec. 4, 1973.  
  This invention relates generally to apparatus for forming holes in metal sheet material, and is particularly concerned with a punch and die assembly for punching a hole in metal sheet material and extruding the material surrounding the hole to a desired configuration and to apparatus such self dumping hoppers utilizing a platform member having such holes formed therein.  
  US. Pat. No. 2,519,153 discloses a selfdumping hopper having a body supported on a platform for movement between an upright loading position and a tilted dumping position. For controlling the movement of the hopper between positions, teeth or projections on the hopper body engage holes formed in the platform. Each tooth or projection moves into and out of the hole in the platform during movement of the hopper and, consequently, very high stresses are experienced by the material surrounding the holes. Furthermore, the configurations of the holes are important because the teeth must be capable of moving into and out of the holes with a reasonably smooth, uninterrupted rolling motion. An additional requirement for proper operation of the hopper is that the holes in the platform be free of burrs.  
 Heretofore, holes having a substantially cylindrical configuration have proven somewhat unsuitable for application of the general type referred to in the preceding paragraph because the slightest amount of misalignment will cause the teeth to clash against the edges of the holes thereby interfering with the movement of the hopper. To merely make the holes larger would create the possibility of a greater amount of misalignment and would be therefore unacceptable. Additionally, most of the presently available methods and apparatus for forming holes have the disadvantages that burrs must be removed from the material surrounding the holes after the hole forming operation, and the configurations of the material surrounding the holes do not adequately increase the bearing strength of the material so that heavier gauge or higher strength material is necessary merely to prevent failure at the holes. Examples of prior art hole forming apparatus are disclosed in the following US. Pat. Nos. 939,342; 1,979,748; 2,198,986; 2,306,658; 2,887,157; and 3,494,168.  
  An object of this invention is to provide hole forming apparatus for forming a hole in high strength metal sheet material in such a manner that no burrs project into the hole from the surrounding material following the hole forming operation, and wherein the material surrounding the hole is formed into a configuration that will withstand high bearing stresses and that will permit smooth operation of a toothed rocking member on a platform having holes formed therein for receiving the teeth of the rocking member.  
  Another object of this invention is to provide a hole forming apparatus including a punch having a cutting portion at its leading end for cutting and punching a hole in a metal sheet and a forming portion following the cutting portion for shaping the material of the metal sheet surrounding the hole; the cutting portion comprising a cutter extending from the leading end of the punch and a forming portion including a flared section providing a material forming shoulder, a cylindrical section having a greater lateral dimension than the cutter, and an outwardly radiused section; and a die for cooperation with the punch for shaping the material of the metal sheet surrounding the hole.  
  Another object is to provide a platform member for a rocker and platform assembly comprising a load supporting and carrying surface having holes formed therein, wherein the material at the periphery of the holes includes a first section bounded by the platform member and substantially in the plane thereof and a second section comprising a reinforcing collar extending from one of the surfaces of the platform member for increasing the thickness of the material surrounding the holes; the first section having a substantially arcuate inner surface and the second section having a substantially cylindrical inner surface and substantially arcuate outer surface.  
  Other objects and features of the invention will become apparent from the following description taken in connection with the accompanying drawings wherein:  
  FIG. 1 is a cross sectional view of hole forming apparatus including a punch and die assembly constructed in accordance with the instant invention;  
  FIG. 2 is an elevational view of the punch of the punch and die assembly of FIG. 1;  
  FIG. 3 is a cross-sectional elevational view of the die of the punch and die assembly of FIG. 1;  
  FIG. 4 is a partially cut-away perspective view of a structural member having a hole formed therein with the material surrounding the hole having a configuration according to the invention; and  
  FIG. 5 is an elevational view, partly in cross-section, of a toothed rocker member and a platform formed with a series of holes for guiding the teeth of the rocker member.  
  In the drawings, a hole forming apparatus is illustrated including a punch and die designated collectively by reference numerals 11) and 12 respectively.  
  The punch 10 includes a cutting portion comprising a cutter 14 at its leading end for cutting and punching a hole in a metal sheet. Following the cutter 14 is a forming portion indicated at 15 for shaping the material of the metal sheet surrounding the hole. The forming portion 15 includes a flared section 20 providing a material deforming shoulder which has the general configuration of an inverted truncated cone. The flared section 20 flares outwardly and merges into a cylindrical section 18 which has a greater lateral dimension than the cutter 14, that is, the diameter of the cylindrical section 18 is larger than the diameter of the cutter 14. The cylindrical section 18 meets the terminal section of the forming portion 15 which is an outwardly radiused section 22. Following the radiused section 22 is a built up or enlarged section 26 which provides strength to the radiused section 22 while the punch 10 is used. The punch 10 also includes a shank 28 for mounting the punch 10 in any appropriate force generating mechanism such as the mechanical press generally indicated at 30.  
  The die 12 is designed to cooperate with the punch for shaping the material of the sheet metal surrounding the hole. The die 12 includes an upper surface 34 having a cylindrical recess 38 formed therein for receiving at least a portion of the material surrounding the hole, and a channel or bore 36 in communication with the recess 38 for receiving the cut material from the metal sheet. An areuate shoulder 40 defines the outer periphery of the recess 38 and aids in shaping the material of the metal sheet surrounding the hole during a hole forming operation. The channel 36 also includes a pilot portion 37 for guiding at least a portion of the forming portion of the punch 10 to the die 12. An annular flange 42 is included at the base of the die 12 for mounting the die in axial alignment with the punch 10.  
  The platform member 16 includes a load supporting and carrying surface having holes 62 formed therein by utilization of the punch 10 and die 12 as shown in FIG. 4. The platform member 16 is especially suited for use in the type of self dumping hopper disclosed in US. Pat. No. 2,519,153. because the configuration of the holes provide for smoother operating of the hopper as is set forth below. Furthermore, the holes are formed in such a manner that no burrs project into the holes from the surrounding material, and the material surrounding the holes is thickened so that they will withstand higher bearing stresses exerted by the teeth or projections on the hopper thereby permitting a lighter gauge steel sheet to be used while maintaining the same strength at the holes afforded by a steel sheet of heavier gauge.  
  The material at the periphery of the hole 62 includes a first section 64 having a substantially areuate inner surface bounded by the platform member 16 and substantially in the plane thereof, and a second section 66 having a substantially cylindrical inner surface and formed by a reinforcing collar 68 projecting beneath the plane of the member 16 for increasing the thickness of the material immediately surrounding the hole 62. The reinforcing collar 68 also includes a substantially areuate outer surface 69.  
  One of the primary purposes of this invention is to utilize the platform member 16 in an assembly as best shown in FIG. 5. The assembly generally shown at 70 includes an arcuate rocker member 72 and the platform member 16 which elements may be described as a section of the curved rocker portion of the hopper and a section of the platform of the type disclosed in US. Pat. No. 2,519,153. Accordingly, the arcuate rocker member 72 is adapted to rock across the surface of the platform member 16. The areuate rocker member 72 includes a plurality of projections 74 in the form of truncated conical teeth, and the platform member 16 includes a plurality of holes 62 therein having the configuration as described for receiving the projections 74 and thereby guiding and retaining the arcuate member as it moves over the platform member 16 with a rolling motion. The projections or teeth 74 are normally arranged linearly on the arcuate member at spaced intervals to mesh with the similarly spaced holes 62 on the platform member 16.  
  One of the important advantages achieved by utilizing a platform member 16 having holes 62 of this configuration is that the projections or teeth 74 are guided into the holes 62 by the arcuate surface 64 thereby allowing a smoother rocking motion between the arcuate member and the platform member. In other words, the inner surfaces of the first and second sections 64 and 66, respectively, form a substantially bell-shaped opening having a substantially flat bottom surface 68 spaced from the plane of the sheet 16 whereby the teeth on the rocker are guided into and out of the holes when the teeth engage the arcuate surface of the first section. Furthermore, the arcuate section 62 increases the size of the entryway into the hole, therefore, misalignment problems are not as critical as those encountered with holes of a more conventional configuration. Even though the size of the holes are increased at the entryway there is no additional misalignment problem involved because the size of the major portion of the hole 62 remains unchanged.  
  In operation, the punch 10 and die 12 are mounted in a mechanical press 30 as shown in FIG. 1. The mechanical press 30 includes a vertically movable head 46 and a tool chuck 48 for receiving the shank 28 of the punch 10. The dic 12 is mounted on a worktable or other support designated by reference numeral 44 in axial alignment with the punch 10 and is held securely in position by block 50 which is fastened to the worktable 44 and tightly clamps against the annular flange 42 on the die 12.  
  The platform member 16 is inserted in the press 30 and abuts stop 45 which is mounted on the worktable 44 by fasteners 47. A vertically movable guide head 52 moves into engagement with the platform member 16 and clamps it in position against the upper surface of the block 50 on the worktable 44. When the press 30 is actuated the punch 10, mounted in vertically movable head 46, moves downwardly and is guided in bore 54 of guide head 52 to engage the platform member 16.  
  Initially the cutter 14 engages the platform member 16 to cut and punch a slug of metal from the platform member 16 to form a hole. The cut slug (not shown) passes through the channel 36 formed in the die 12 and enters a discard channel in the worktable 44 which conveys the cut slug away from the work area to a discard area.  
  After the cutter has formed a hole 62 in the platform member 16 the flared section 20 engages the material surrounding the hole and begins to force or extrude it downwardly into the recess 38 of the die 12. Continued downward movement forces more of the metal into the recess 38 until the radiused section 22 engages the platform member 16 to complete the forming operation. Consequently, the hole takes on the configuration as shown in FIG. 4, that is, the areuate section 64 formed by the radiused section 22 on the punch 10 is formed on the upper surface of the platform member 16 and the second section 66 .having a cylindrical surface formed by the cylindrical section 18 of the punch 10. The reinforcing collar 68 is formed within the recess 38 of the die 12 and includes an arcuate outer surface formed by areuate shoulder 40 disposed about the periphery of the recess 38 on the die 12. No burrs project into the hole because the edge of the hole as initially punched out by cutter 14 is turned 90 away by the forming portion as indicated at 68 and is forced into engagement with the surface of recess 38.  
  During the forming operation the punch 10 is held in axial alignment with the guide 12 by means of the pilot portion 37 included in channel 36 which engages the cylindrical portion 18 of the punch 10 as the punch 10 moves to the die 12. Furthermore, the punch 10 is prevented from lateral misalignment during the initial stages of engagement with the platform member 16 by means of the lower 54 in the die head 52.  
  Following the formation of the hole 62 in platform member 16 the punch 10 is retracted from the die as the vertically movable head 46 draws the punch upwardly to the interior of the press 30. Coordinated with this movement is the upward movement of the guide head 52 which removes the clamping pressure on the platform member 16 which has held it in place against the block 50 on the worktable 44. Following the retraction of the guide head 52 and punch the platform member 16 is lifted slightly upwardly to clear the die and is then removed from the press 30.  
  While a specific embodiment of the invention has been described and illustrated in the foregoing specification and accompanying drawings. it should be understood that the invention is not limited to the exact construction shown. Alterations and modifications, all falling within the scope and spirit of the invention. will be apparent to those skilled in the art.  
  The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
  1. In a tooth-guided rocker and platform assembly for self dumping hoppers and the like wherein a toothed rocker is supported on a platform of high strength material having a plurality of linearly spaced holes therein whereby the teeth on the rocker move into and out of the holes with a substantially rolling motion as the rocker rocks across the surface of the platform for guiding and retaining the rocker on the platform, the improvement comprising the configuration of the material adjacent the periphery of each of said holes including a first section bounded by the platform and substantially in the plane thereof, and a second section comprising a reinforcing collar which defines inner and outer surfaces extending from the lower surfaces of the platform opposite the rocker supporting surface for increasing the thickness of the material surrounding said hole; said first section having a substantially cylindrical inner surface; said inner surfaces of said first and second sections forming a substantially inverted bellshaped guiding surface surrounding said opening whereby the teeth on the rockers are guided into and out of said holes when the teeth engage said arcuate surface of said first section. said arcuate outer surface of said second section extending from the lower surface of the platform, and a flat bottom extending between said inner and outer surfaces of said second section, said flat bottom lying in a plane perpendicular to the axis of the opening and spaced from the lower surface of the platform.  
  2. An assembly as claimed in claim 1 wherein the teeth have a substantially truncated conical configura