Retractable access system ladder and work machine using same

• US 7,870,932 B2
• Filed: 09/27/2004
• Issued: 01/18/2011
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Lapke, Robert A., Scheidenhelm, Kurt J., Beaupre, Eric J.
• Primary Examiner(s): Mitchell; Katherine W
• Assistant Examiner(s): Quinn; Colleen M
• Application Number:
  US10/950,956
• Publication Number:
  US 20060070804A1
• Time in Patent Office: 2,304 Days
• Field of Search: 162/21, 162/42, 162/44, 163/54, 16/54, 161/95, 162/01, 16/71, 16/79, 182/86, 182/97, 182/127, 248/210, 248/309.1, 248/316.4, 248/316.5, 224/405, 224/324, 224/325, 224/326
• US Class Current: 182/127
• CPC Class Codes: B60R 3/02 Retractable steps or ladders, e.g. movable under shock B60R3/005 takes precedence
• CPC Class Codes: E02F 9/0833 Improving access, e.g. for maintenance, steps for improving driver's access, handrails
• CPC Class Codes: E06C 5/02 with rigid longitudinal members
• CPC Class Codes: E06C 5/04 capable of being elevated or extended ; Fastening means during transport, e.g. mechanical, hydraulic

Abstract

A work machine and work machine access ladder assembly are provided. The work machine includes a work machine body having an operator platform. A hinge mechanism is coupled to the work machine body and defines a hinge axis oriented diagonally with respect to a vertical line. The ladder may be rotated about the hinge axis between a use and a stowed position.

Claims

1. A machine access ladder assembly comprising:

a ladder having first and second side rails that terminate at a top end of the ladder, and a plurality of steps connected between the first and second side rails below the top end;

a hinge mechanism having a first hinge portion mounted to said first side rail closer to a top step than the top end of the ladder, and a second hinge portion pivotably coupled to said first hinge portion via a pin, said pin being fixed to one of the first hinge portion and the second hinge portion, said second hinge portion including mounting features for mounting the same to a machine;

said pin of said hinge mechanism being spaced a distance away from said first side rail in a direction perpendicular to the first and second side rails, and said pin defining a hinge axis oriented diagonally with respect to said rails such that the ladder flips front to back and vertical to horizontal when rotated by the hinge mechanism from a deployed position to a stowed position; and

an actuator disposed to engage a toothed collar of said pin, wherein the actuator is operable to rotate the pin and the one of the first hinge portion and the second hinge portion relative to the other of the first hinge portion and the second hinge portion;

wherein said actuator is operable to torque said first and second hinge portions one against the other.

2. The ladder assembly of claim 1 wherein said actuator is a rotational actuator, said actuator including at least one of a hydraulically, pneumatically or electrically powered actuator.

3. The ladder assembly of claim 1 wherein said actuator is a linear actuator.

4. The ladder assembly of claim 1 wherein said toothed collar is disposed proximate a center of said pin and rotatable within a space defined by at least one of said first and second hinge portions.

15. The ladder assembly of claim 1 further comprising a cradle disposed to secure an end of the ladder remote from hinge mechanism and configured to engage the first and second side rails to restrain the ladder in the cradle when the ladder is in the stowed position.

16. The ladder assembly of claim 15 wherein the cradle includes a cradle actuator configured to move the cradle between an open position and a closed position.

17. The ladder assembly of claim 16 wherein the actuator is a hinge actuator;

and

further comprising an electronic control system configured to control the hinge actuator and the cradle actuator, wherein when the ladder reaches the cradle, the electronic control system halts the actuator and activates the cradle actuator to secure the ladder in the stowed position.

5. A machine access ladder assembly comprising:

a ladder having first and second side rails and a plurality of steps connected between the first and second side rails to define a front face, a back face, a first side face and a second side face;

a hinge mechanism having a first hinge portion mounted to one of said first side face and said second side face, and a second hinge portion pivotably coupled to said first hinge portion via a pin, said pin being fixed to one of the first hinge portion and the second hinge portion, said second hinge portion including mounting features for mounting the same to a machine;

said pin of said hinge mechanism being spaced a distance away from said first side rail in a direction perpendicular to the first and second side rails, and said pin defining a hinge axis oriented diagonally with respect to said rails such that the ladder flips front to back and vertical to horizontal when rotated by the hinge mechanism from a deployed position to a stowed position; and

a cradle configured to engage the first and second side rails to restrain the ladder in the cradle when the ladder is in the stowed position;

wherein said hinge mechanism comprises an actuator operable to torque said first and second hinge portions one against the other.

6. The ladder assembly of claim 5 wherein said actuator is a rotational actuator, said actuator including at least one of a hydraulically, pneumatically or electrically powered actuator.

7. The ladder assembly of claim 5 wherein said pin includes a geared collar disposed proximate a center thereof and rotatable within a space defined by at least one of said first and second hinge portions.

8. The ladder assembly of claim 5 wherein the hinge axis is positioned and oriented such that the ladder rotates through a 90 degree angle from the deployed position to the stowed position.

18. The machine access ladder assembly of claim 5 wherein said cradle includes a latch movable between an open position and a closed position by a cradle actuator.

9. A machine access ladder assembly comprising:

a ladder having first and second side rails and a plurality of steps connected between the same;

a hinge mechanism having a first hinge portion attached to cover a portion of said first side rail, and a second hinge portion pivotably coupled to said first hinge portion by a pin, said second hinge portion including mounting features for mounting the same to a machine;

said pin of said hinge mechanism being spaced a distance away from said first side rail in a direction perpendicular to the first and second side rails, and said pin defining a hinge axis oriented at a diagonal with respect to said rails such that the ladder flips front to back and vertical to horizontal when rotated by the hinge mechanism from a deployed position to a stowed position; and

a cradle configured to engage the first and second side rails to restrain the ladder in the cradle when the ladder is in the stowed position, wherein the cradle is disposed to secure an end of the ladder remote from hinge mechanism;

wherein said hinge mechanism comprises an actuator operable to torque said first and second hinge portions one against the other.

10. The ladder assembly of claim 9 wherein said actuator is a rotational actuator, said actuator including at least one of a hydraulically, pneumatically or electrically powered actuator.

11. The ladder assembly of claim 9 wherein said actuator is a linear actuator.

12. The ladder assembly of claim 11 wherein:

said actuator is mounted to one of said first and second hinge portions and includes a plurality of gear teeth disposed thereon;

the other of said hinge portions includes a geared member connected therewith and engageable against said actuator; and

said actuator being operable to rotate said geared member to pivot the connected hinge portion relative to the other of said hinge portions.

13. The ladder assembly of claim 12 wherein said geared member comprises a pin coupling said first and second hinge portions together, said pin including a geared collar disposed proximate a center thereof and rotatable within a space defined by at least one of said first and second hinge portions.

14. The ladder assembly of claim 9 wherein the hinge axis is positioned and oriented such that the ladder rotates through a 90 degree angle from the deployed position to the stowed position.

19. The machine access ladder assembly of claim 9 wherein said cradle includes a latch movable between an open position and a closed position by a cradle actuator.