Trench shield ladder

• US 6,907,957 B1
• Filed: 12/01/2003
• Issued: 06/21/2005
• Est. Priority Date: 06/25/2002
• Status: Expired due to Fees

• Current Assignee: OLS Incorporated
• Original Assignee: Arthur Allen Couch
• Inventors: Couch, Arthur Allen
• Primary Examiner(s): THOMPSON, HUGH B
• Application Number:
  US10/724,916
• Time in Patent Office: 568 Days
• Field of Search: 182/206, 182/106, 182/194, 182/129, 182/83, 405/272, 405/273, 405/282, 405/283
• US Class Current: 182/206
• CPC Class Codes: E02D 17/08 Bordering or stiffening the sides of ditches trenches or narrow shafts for foundations
• CPC Class Codes: E04G 27/00 Temporary arrangements for giving access from one level to another for men or vehicles, e.g. steps, ramps for scaffolds E04G5/10; gangways B63; lifts B66
• CPC Class Codes: E06C 1/36 Ladders suspendable by hooks or the like ladderhooks E06C7/505
• CPC Class Codes: E06C 9/02 rigidly mounted

Abstract

A trench shield ladder that hangs on the wall of the trench shield to provide workmen safe access to a trench. The ladder is provided with a top platform and hand rails that extend over the platform. The ladder can be adjusted in length by employing an extension portion with hooks that hang the extension on the main rungs of the main ladder. The extension portion is not as wide as the main portion of the ladder so that the legs of the extension rest between the legs of the main portion of the ladder. The ladder and extension are provided with stand off arms that hold the main and extension rungs of the ladder away from the wall of the trench shield. The present invention is designed to fit on trench shields of varying thicknesses.

Claims

1. A trench shield ladder in combination with a trench shield comprising:

two spaced apart trench shield walls, a plurality of support rods attaching between the two spaced apart trench shield walls to hold them apart and forming a working space between the two trench shield walls,

two approximately parallel front legs for removably engaging an inwardly facing surface of a first trench shield wall, spaced apart main rungs extending between the two legs,

a top platform attached approximately perpendicular to upper ends of said legs for engaging said first trench shield wall, hand rails extending over the platform,

at least one rear leg attached approximately perpendicular to said top platform and approximately parallel to said front legs for engaging an opposite outwardly facing surface of said first trench shield wall, said hand rails being continuous with both said front and said rear legs, and each of said front legs and each of said rear legs being rigidly secured relative to said platform.

2. The trench shield ladder in combination with a trench shield according to claim 1 further comprising:

stand off arms provided on the front legs to removably engage an inwardly facing surface of said first trench shield wall to hold the main rungs of the ladder away from the first trench shield wall while still allowing the ladder to be moved relative to the first trench shield wall.

3. The trench shield ladder in combination with a trench shield according to claim 1 wherein the front legs are spaced apart from said at least one rear leg a sufficient distance to allow the front and rear legs to receive trench shield walls of varying thicknesses.

4. The trench shield ladder in combination with a trench shield according to claim 1 further comprising:

an extension portion removably added to the bottom of the front legs, said extension portion having two extension legs with hooks at the upper end of each extension leg for removably hanging the extension portion on the main rungs, and spaced apart extension rungs extending between the extension legs.

5. The trench shield ladder in combination with a trench shield according to claim 4 further comprising:

stand off arms provided on the extension legs to removably engage an inwardly facing surface of the first trench shield wall to hold the extension rungs away from the first trench shield wall while still allowing the ladder to be moved relative to the first trench shield wall.

6. A trench shield ladder in combination with a trench shield comprising:

two spaced apart trench shield walls, a plurality of support rods attaching between the two spaced apart trench shield walls to hold them apart and forming a working space between the two trench shield walls,

a front ladder with two front legs, spaced apart main rungs extending approximately perpendicular to and between said front legs, a top platform attached approximately perpendicular to said front ladder at an upper end of said front ladder, and at least one rear leg attached approximately perpendicular to said top platform and approximately parallel to said front legs and spaced apart from said front legs, hand rails being continuous with both said front and said rear legs, and

each of said front legs and each of said rear legs being rigidly secured relative to said platform.

7. The trench shield ladder in combination with a trench shield according to claim 6 further comprising:

at least one hand rail attached to said platform and extending over the platform.

8. The trench shield ladder in combination with a trench shield according to claim 6 further comprising:

stand off arms provided on the front legs and extending toward the at least one rear leg to removably engage an inwardly facing surface of a first trench shield wall in order to hold the main rungs of the front ladder away from the first trench shield wall while still allowing the ladder to be moved relative to the first trench shield wall.

9. The trench shield ladder in combination with a trench shield according to claim 6 wherein the front legs are spaced apart from said at least one rear leg a sufficient distance to allow trench shield walls of varying thicknesses to be removably inserted between the front and rear legs.

10. The trench shield ladder in combination with a trench shield according to claim 6 further comprising:

an extension portion removably added to the bottom of the front legs, said extension portion having two extension legs with hooks at the upper end of each extension leg for removably hanging the extension portion on the main rungs, spaced apart extension rungs extending between the extension legs.

11. The trench shield ladder in combination with a trench shield according to claim 10 further comprising:

rearwardly extending stand off arms provided on the front legs and the extension legs to removably engage an inwardly facing surface of the first trench shield wall in order to hold the main rungs and the extension rungs away from the first trench shield wall while still allowing the ladder to be moved relative to the first trench shield wall.