| 摘要 |
An access device that provides access between a substrate surface and an elevated surface includes a mounting for securing the device below the elevated surface, a first ladder member pivotally attached to the mounting, a second ladder member pivotally attached to the first ladder member, drive mechanism connected between the mounting and the first ladder member, and a guide arm connected between the mounting and the second ladder member to guide movement of the second ladder member as the drive mechanism moves the first ladder member. User operation of the drive mechanism moves the device between an access position, where the first and second ladder members are coaligned and extend angularly outwardly and downwardly from the elevated surface, and a storage position, where the first and second ladder members are retracted and vertically disposed adjacent to the mounting, with the second ladder member inverted relative to the first ladder member. |
| 主权项 |
1. An access device, adapted to provide access between a substrate surface and an elevated surface of a vehicle, including:
a mounting, to support said device below said elevated surface of said vehicle; a first ladder member, a first end of which is pivotally attached to an upper end of said mounting at a pivot point; a second ladder member, a first end of which is pivotally attached to a second end of said first ladder member at a pivotal connection; a drive mechanism, operatively connected between said mounting and said first ladder member, to control the movement of said access device between an access position and a storage position, the drive mechanism including: a rotatable member having three pivotal connectors spaced apart in a triangular arrangement; a first of said connectors attached to an intermediate portion of said mounting via a mounting arm; a second of said connector attached to an intermediate portion of said first ladder member via a control arm; and a third of said connectors attached to an upper portion of said mounting via an extendable arm; and a guide arm, including first and second pivotally connected guide arm members, operatively connected between a lower end of said mounting and an intermediate portion of said second ladder member, to guide the movement of said second ladder member as said drive mechanism moves said first ladder member, whereby user operation of said drive mechanism controls the extension or contraction of said extendable arm to thereby control the operation of said access device between an access position and a storage position, in which, in said access position, each of said first and second ladder members are substantially coaligned and extend angularly outwardly and downwardly from said elevated surface but without contacting said substrate surface, and wherein the extendable arm is in an extended state in the access position; in said storage position, each of said first and second ladder members are retracted in a substantially vertically disposed manner adjacent to said mounting and below said elevated surface, said second ladder member being substantially inverted relative to said first ladder member, wherein the extendable arm is in a contracted state in the storage position, and wherein in the extended state the extendable arm is longer than when in the contracted state, and wherein the pivotal connection is disposed below the pivot point in the access and the storage positions. |
