Access door for cylinder
United States Patent [191 Gordon Apr. 1, 1975 ACCESS DOOR FOR CYLINDER [76] Inventor: Jerry D. Gordon, 10765 E. 11th St., Tulsa, Okla. 74119 [22] Filed: June 21, 1973 [21] Appl. No.: 372,395  
 [51] Int. Cl B65d 45/00 [58] Field of Search 220/25; 138/92 [56] References Cited UNITED STATES PATENTS 291,771 l/l884 Rasgorshek 220/25 564,251 7/1896 Long 220/25 1,759,732 5/1930 Charlot 220/25 2,306,699 12/1942 Johnson 220/25 2,551,827 5/1951 Curtis 138/92 X 3,391,817 7/1968 Shaw 220/25 3,394,834 7/1968 Cigliano 220/25 3,403,703 10/1968 Reimann 138/92 3,624,794 11/1971 Futty 138/92 X Primary Examiner-William 1. Price Assistant ExaminerSteven M. Pollard Attorney, Agent, or FirmWilliam S. Dorman [57] ABSTRACT An access door for a rectangular opening in the cylindrical wall of a cylinder comprising a curved rectangular plate of somewhat larger size than the opening in the cylinder, a gasket surrounding the side edges of the rectangular plate and providing a margin of gasket material along the side edge of the plate against the cylinder; the door also includes an arcuate, but somewhat resilient, locking band of substantially the same length as the rectangular plate; a short rod projects radially outwardly from the center of the locking band and projects through a hole in the center of the curved rectangular plate; on the end of the rod which projects through the curved plate is mounted a pivotal handle which is secured to the outer end of the rod by means of a set pin, the latter being held in place by means of a locking pin; the handle has a curved or cammed portion which bears against the outer curved surface of the curved rectangular plate and the hole in the handle through which the set pin passes is eccentrically positioned with respect to the cammed surface; thus, with the handle perpendicular to the curved rectangular plate, the band is in its maximum position away from the plate; with the handle turned against the curved rectangular plate in the opposite position, substantially 90 away from the position previously described, the band will be drawn to its closest position with respect to the plate; the plate is also provided with a pair of stiffening braces on the interior of the plate to prevent the latter from getting out of shape through mishandling, dropping, etc.; a pair of positioning pins or lugs are located on the interior surface of the plate adjacent the bottom edge.  
 2 Claims, 4 Drawing Figures PATENTS] APR 1 SHEEIlOfZ Fig. 1  
 Fig. 2  
 AIENTEHAPR H975 3; 874.550  
 SE-EET 2 BF 2 Fig. 3  
 Fig. 4  
 ACCESS DOOR FOR CYLINDER CROSS-REFERENCE TO RELATED APPLICATION This application discloses and claims an access door which is partly disclosed, but not claimed, in application Ser. No. 327,063, filed June 21, 1973, and entitled AUTOMATIC BREADING DEVICE.  
 BACKGROUND OF THE INVENTION I. Field of the Invention The present invention relates to an access door for a cylinder and, more particularly, an access door which can be properly positioned and locked in place.  
 2. The Prior Art The feature of providing a curved door for an opening in a cylindrical member is shown to be old by Rasgorshek US. Pat. No. 291,771. Eccentrically mounted handles are also known in the art. The feature of using a gasket on a door is, of course, old. As far as the combination of features disclosed in the present invention, the prior art does not show or suggest the same.  
 SUMMARY or THE INVENTION The apparatus of the present invention involves a substantially rectangular and curved door adapted to fit over a substantially rectangular opening in the curved surface of a cylindrical member. The door includes a curved rectangular plate of somewhat larger size than the opening in the cylinder. The door is also provided with a gasket which surrounds the side edges of the door so as to bear against the cylinder when the door is properly positioned. Slidably mounted on the plate is a relatively rigid, but somewhat resilient, locking band which is arcuate in shape. A rod projects radially outward from the center of the locking band and is adapted to project through a hole in the curved plate. Preferably, the rod and the hole are square in cross section to prevent misalignment of the locking band. At any event, the rod projects through the hole and its outer end engages a handle which is secured to the outer end of the rod by means of a set pin. The set pin passes through holes in the handle and the hole in the rod. A locking pin can be inserted in the end of the set pin to hold the same in place. The holes in the handle are eccentrically positioned so that the handle acts as a cam to force the locking band into locking position when the curved plate is properly set over the opening in the cylindrical member. On the inner surface of the curved plate is mounted a pair of braces which are welded to the plate and which provide reinforcement to p event the plate from getting out of shape through mishandling, dropping, etc. A pair of positioning pins or lugs are located on the interior surface of the curved plate adjacent the bottom edge.  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded and perspective view of the cylinder, door and door components;  
  FIG. 2 is a perspective of the underside of the door without the gasket thereon;  
  FIG. 3 is a partial sectional view through the door and cylinder showing the door as it is inserted into the opening in the cylinder; and  
  FIG. 4 is a partial sectional view of the door and cylinder showing the door locking in position.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in detail, FIG. 1 shows a cylinder 10 having a substantially rectangular opening 12 on the curved surface 14. Also shown is a curved rectangular plate 16 of somewhat larger size than the opening 12, but having substantially the same curvature as that of the cylinder 10. The plate 16 is provided with a gasket 18 which is adapted to surround the side edges of the door and provide a margin of rubber or gasket material along the side edge of the door against the cylinder 10. The plate 16 has a straight bottom edge 17 and an opposite straight top edge 19, both edges being substantially parallel to the central axis of the cylinder 10 when the plate is in position against the cylinder. The plate 16 also has a pair of spaced and curved side edges, both identified by the reference numeral 21, and lying in planes normal to the axis of the cylinder 10 when the plate 16 is positioned over the cylinder 10 as shown in FIGS. 3 and 4. Cooperation with the plate 16 is a relatively rigid, but somewhat resilient, locking band 20 which is arcuate in shape and which is of substantially the same length as the length of the plate 16. A rod 22 having a substantially square cross section, projects radially outward from the center of the locking band 20 and is adapted to project through a square hole 24 in the plate 16, the square hole being of substantially the same size as the cross-sectional size of the rod 22.  
  A handle 26 is secured to the outer end of the rod 22 by means ofa set pin 28 which passes through holes 30 in the handle and a hole 32 in the rod 22. A round washer 33 having a square hole in the center is mounted on the rod 22 between the handle 26 and the curved surface of the curved rectangular plate 16. A locking pin 34 can be employed to hold the set pin 28 in place, if desired. With the handle in-the position shown in FIG. 3, the band 20 is in its maximum position away from the concave surface of the plate 16; with the handle 26 in the folded-down position as shown in FIG. 4, the band 20 is drawn to its closest position with respect to the plate 16.  
  As best shown in FIG. 2, a pair of braces 36 are welded to the interior of the plate 16 for the purpose of providing reinforcement to prevent the plate from getting out of shape through mishandling, dropping, etc. The major straight portions of these reinforcing braces 36 are substantially chordal with respect to the central axis of the cylinder 10 when the plate 16 is in the closed position shown in FIG. 4. A pair of positioning pins 38 are also located on the interior surface of the plate adjacent the bottom edge 17.  
  The handle 26 has a cam member 40 formed by a first relatively flat portion 42 connecting with a second relatively flat portion 44 by means of the rounded portion 46. The holes 30 in the handle 26 are closer to the flat portion 44 than they are to the flat portion 42 to effect the camming action to be described below.  
  Turning now to a consideration of FIG. 3, the door 16, with gasket 18, band 20, handle 26, etc., attached, is inserted into the opening 12 by tipping the lower end of the plate 16 slightly upwardly as shown by the arrow 48 so that the upper edge 19 of the plate is outside of the cylinder 10 and the upper end of the locking band 20 is inside the cylinder. The door is moved upwardly (towards the right as shown by the arrow 50) from this position until the lower end of the locking band 20 can pass beyond the lower edge 52 of the opening 12. At this point, the lower end of the door 16 is moved radially inward towards the cylinder opposite to the direction of the arrow 48 so that the door now lies flat against the curved surface 14 of the cylinder. The door is now moved downwardly (towards the left) until the positioning lugs 38 comes to rest against the lower edge 52 of the opening 12. At this point, the door is properly positioned and the handle 26 is rotated clockwise to lock the door in position as shown in FIG. 4. The locking action takes place, of course, by virtue of the fact that the ends of the locking band 20 are urged against the inside of the cylinder adjacent the centers of the upper and lower edges of the opening 12.  
  The locking action is effected by the cam 40 on the handle 26. The cam 40 bears against the convex surface of the rectangular plate 16, or more properly, against the washer 33 which is interposed between the handle and the plate. Since the holes 30 in the handle 26 are closer to the flat portion 44 of the cam, when the handle is turned clockwise until the flat portion 42 is against the washer 33, the rod 22 will be drawn out radially to its maximum extent and the locking band 20 will be at its closest position with respect to the concave surface of the curved rectangular plate 16.  
  Whereas the present invention has been descrived in particular relation to the drawings set forth herein, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention.  
 What is claimed is:  
  1. An access door for a rectangular opening in the cylindrical wall ofa cylindrical member comprising a substantially rectangular and curved plate having substantially the same curvature as that of the cylindrical wall and having a size somewhat larger than the opening in the rectangular wall, said curved rectangular plate being further defined by a pair of spaced and straight end edges parallel to the axis of the cylindrical member and a pair of curved side edges spaced from each other and lying in planes normal to the central axis of the cylindrical member, a curved and resilient locking band radially slidably mounted against the concave face of said curved rectangular plate and being disposed generally parallel to the curved side edges of said locking plate, said curved locking band having a length substantially equal to the distance between the end edges of said plate, a substantially radial rod connected to the center of said locking band and passing through a hole adjacent the center of said plate, a handle mounted on the outer end of said rod adjacent the convex surface of said plate, said handle being mounted on said rod by means of a set pin passing through suitable holes in said handle and said rod, said handle having a cam member adapted to bear against the convex surface of said plate, said holes being mounted eccentrically in said cam member, a gasket surrounding the edges of said curved rectangular plate and adapted to be positioned between said plate and said cylinder when said plate is in position, a pair of stiffening braces secured to the concave surface of said plate and being spaced from each other, said stiffening braces being substantially chordal with respect to the central axis of said cylindrical member and a pair of positioning lugs projecting radially inward towards the central axis of said cylindrical member and being located adjacent one edge of said curved rectangular plate.  
  2. An access door for a cylindrical member as set forth in claim 1 wherein the rod is substantially rectangular in cross section and wherein the central hole in said curved rectangular plate is square and of substantially the same size as the cross sectional size of said rod.