Flatstep ladder

• US 3,349,870 A
• Filed: 08/25/1966
• Issued: 10/31/1967
• Est. Priority Date: 08/25/1966
• Status: Expired due to Term

• Current Assignee: George Lieblein
• Original Assignee: George Lieblein
• Inventors: GEORGE LIEBLEIN
• Application Number:
  US04/575,163
• Time in Patent Office: 432 Days
• US Class Current: 182/228.6
• CPC Class Codes: E06C 7/081 Rungs or other treads comprising anti-slip features
• CPC Class Codes: E06C 7/085 achieved by deforming the rung or the stile E06C7/084 takes precedence
• CPC Class Codes: Y10T 29/4992 by flaring inserted cup or tube end
• CPC Class Codes: Y10T 29/4994 Radially expanding internal tube

Claims

1. IN A LADDER, A LADDER RUNG COMPRISING AN ELONGATED HOLLOW METAL EXTRUSION HAVING A FLAT UPPER SURFACE PORTION, A LIMITED PORTION OF SAID EXTRUSION ADJACENT EACH OF THE OPPOSING ENDS OF SAID HOLLOW EXTRUSION BEING SMOOTHLY FLARED INTO A CIRCULAR CROSS SECTION, AN UPSTANDING CIRCULAR BEAD INTEGRALLY FORMED ON EACH OF SAID CIRCULAR CROSS SECTION PORTIONS AT A LOCATION SPACED FROM THE ADJACENT FREE END OF SAID EXTRUSION TO PROVIDE SHORT SUBSTANTIALLY CYLINDRICAL PORTIONS BETWEEN SAID BEADS AND THE OPPOSING FREE ENDS OF SAID EXTRUSION RESPECTIVELY ADAPTED FOR INSERTION INTO CIRCULAR BEARING HOLES IN A PAIR OF LADDER SIDE RAILS, AND ELONGATED INTEGRAL RIBS FORMED ON SAID FLAT UPPER SURFACE PORTION AND EXTENDING SUBSTANTIALLY UNINTERRUPTED ACROSS SAID BEADS AND ALONG SAID SHORT SUBSTANTIALLY CYLINDRICAL PORTIONS FOR PROVIDING A TREAD SURFACE ON SAID FLAT SURFACE PORTION AND FOR SIMULTANEOULSY PROVIDING LOCKING MEANS ON SAID BEADS AND ON SAID CYLINDRICAL PORTIONS ADAPTED TO LOCK SAID RUNGS AGAINST ROTATION WHEN THE OPPOSING ENDS OF SAID RUNGS ARE MOUNTED IN SAID LADDER SIDE RAIL BEARING HOLES.