Overhead cranes

• US 4,150,625 A
• Filed: 04/20/1977
• Issued: 04/24/1979
• Est. Priority Date: 04/20/1977
• Status: Expired due to Term

• Current Assignee: J H Carruthers & Company Limited
• Original Assignee: J H Carruthers & Company Limited
• Inventors: Cowan, William G.
• Primary Examiner(s): Oresky, Lawrence J.
• Application Number:
  US05/789,081
• Time in Patent Office: 734 Days
• Field of Search: 212/10, 212/11, 212/18, 238/134, 238/144, 238/148, 238/127, 238/128, 105/143, 105/141, 105/145, 104/119, 104/120, 52/179, 52/177, 52/731
• US Class Current: 104/119
• CPC Class Codes: B66C 6/00 Girders, or track-supporting structures, specially adapted for cranes base supporting structures with legs B66C5/00; girders in general E04C3/02
• CPC Class Codes: B66C 7/08 Constructional features of runway rails or rail mountings of general application E01B

Abstract

In overhead cranes of the kind including a box girder fabricated of elongate plates and torsionally loaded by a trolley running on three rails respectively at three corners of the box girder, the structure of the box girder is usually such that flanges project from the corners thereof and prevent proper support of the rails in optimum corner positions in alignment with the walls of the girder. This problem is now solved by providing a rail with an elongate flange and securing the rail and flange respectively to marginal portions of a pair of adjacent plates of the box girder. In this way the rail can be secured in optimum position at the corner of the girder and forms with the flange a member which encloses the corner flange and serves as a stiffener or reinforcement for the corner. In a preferred construction the rail and flange are the respective arms of a generally V-section elongate member enclosing the corner of the girder.

Claims

1. An overhead crane comprising an overhead box girder fabricated of elongate plates and including elongate corner joints at least two composed of first and second marginal portions of a pair of adjacent elongate plates said marginal portions being so interconnected that the first portion overhangs the second portion to provide a corner flange, a track on the box girder, and a wheeled trolley mounted on the track to convey a load along the box girder, wherein the track includes a rail at one of said corner joints, said rail being connected to the first marginal plate portion of the corner joint and extending laterally outwards beyond the corner flange of the corner joint, and an an elongate flange extending laterally from the outer edge of the rail and connected to the second marginal plate portion of the corner joint so that the flange supports the rail and the rail and its supporting flange together enclose the corner joint including the corner flange further said track on the box girder includes a longitudinally extending channel member accommodating a corner joint including the corner flange of the girder one wall portion of the channel member forming the rail and another wall portion of the channel member forming the rail-supporting flange, and said channel member is of generally V-section, so that the rail-supporting flange slopes inwards from the rail towards the second marginal plate portion of the corner joint.

2. A crane according to claim 1, in which the channel member is attached to the marginal plate portions of the corner joint by lines of welding at the longitudinal edges of the rail and rail-supporting flange.

3. An overhead crane according to claim 2, wherein the first and second marginal plate portions of each joint are interconnected by welding.

4. An overhead crane comprising an overhead box girder fabricated of elongate plates and including elongate corner joints at least two composed of first and second marginal portions of a pair of adjacent elongate plates said marginal portions being so interconnected that the first portion overhangs the second portion to provide a corner flange, a track on the box girder at corner joints of the box girder, and a wheeled trolley mounted on the track so as to load the box girder torsionally, wherein the track includes rails connected respectively to the first marginal plate portions of the adjacent corner joints and extending laterally outwards beyond the corner flanges of said corner joints, and elongate flanges extending laterally from the outer edges of the rails and connected respectively to the second marginal plate portions of said corner joints so that the flanges support the rails and at each of said corner joints a rail and its supporting flange together enclose the corner joint including the corner flange further said track on the box girder comprises a plurality of longitudinally extending generally V-section members respectively enclosing corner joints of the box girder so that one set of walls of the members form rails and the other set of walls of the members form rail-supporting flanges extending inwardly from the rails to the second marginal plate portions of the corner joints.

5. An overhead crane according to claim 4, wherein the V-section members are attached to the marginal plate portions of the corner joints by welding at the longitudinal edges of the rails and flanges of the members.

6. An overhead crane according to claim 5, wherein the first and second marginal plate portions of each corner joint are interconnected by welding.