AU2018101227A4 - Emergency Access Ladder - Google Patents

Abstract

Abstract An emergency access ladder has a controlled-release extension portion operated by a latch. The ladder extension portion is mounted to a moveable track. I i 1 [0 ~n 12 fl~: 50 Fig. 1I02 Fig 2 28~ ~~Fg 3 "-2Fg

Description

COMPLETE SPECIFICATION

Invention title:

“EMERGENCY ACCESS LADDER”

Applicant:

BEND-TECH INVESTMENTS 1 PTY LTD

Associated provisional applications: 2018903008 filed 16 August 2018

The following statement is a full description of the invention, including the best method of performing it known to me:

2018101227 24 Aug 2018 “EMERGENCY ACCESS LADDER”

Field ofthe Invention [0001] The present invention relates to an extendible ladder for emergency access, suitable for use on vehicles as well as in industrial environments.

Background to the Invention [0002] Large vehicles used in the mining industry, such as loaders, often have platforms which are elevated from the ground. In order for an operator to gain access to such a platform, the vehicle may be positioned next to an access stairwell. In some cases, the vehicle may have its own outer stair arrangement.

[0003] It is also necessary to provide emergency access for an operator. Such access is generally provided by a ladder which extends downwardly from the elevated platform to a position near the ground. Such emergency access ladders typically are at least partially formed from rubber, which is able to withstand impact. Given the proximity of the base of such ladders to the ground, however, it is difficult to avoid some damage to the ladder during use ofthe loader.

[0004] One alternative which has been proposed has a ladder with a lower section connected by a hinge to an upper section. When access is required, this lower section can be swung into a useable position. Such action is inherently dangerous to any workers in the vicinity.

[0005] The present invention seeks to provide an alternative ladder for use with large vehicles. It will also be understood that the ladder can be employed in other situations, such as in process plants and other industrial environments.

Summary of the Invention [0006] According to one aspect of the present invention there is provided an emergency access ladder, the ladder having a frame for fixed attachment to

2018101227 24 Aug 2018 a base surface, the frame including at least one fixed rung, the ladder including a moveable track connected to the frame and constrained to move in a vertical direction relative to the frame, the ladder also including a ladder extension portion having at least one rung, the ladder extension portion being connected to the moveable track and being constrained to move in a vertical direction relative to the moveable track; wherein the frame includes a latch moveable between a hold position in which it restricts downward movement of the ladder extension portion and a release position in which it permits downward movement of the ladder extension portion.

[0007] Preferably the latch is biased into the hold position.

[0008] The latch may have an associated handle which can be operated to move the latch into the release position. It is preferred that the latch is arranged to permit upward movement of the ladder extension portion when in both hold position and release position.

[0009] It is preferred that the ladder extension portion includes a means to control the rate of downward movement. This control means may be a toothed bar or rack arranged to engage with a toothed wheel or pinion fixed to the frame. The toothed wheel may have an adjustable damping means to allow variation in the rate of descent.

Brief Description of the Drawings [0010] It will be convenient to further describe the invention with reference to preferred embodiments of the present invention. Other embodiments are possible, and consequently the particularity of the following discussion is not to be understood as superseding the generality of the preceding description of the invention. In the drawings:

[0011] Figure 1 is a perspective of a ladder in accordance with the present invention; shown in a stowed position;

[0012] Figure 2 is a reverse perspective of the ladder of Figure 1;

2018101227 24 Aug 2018 [0013] Figure 3 is a perspective of the ladder of Figure 1, shown in a deployed position;

[0014] Figure 4 is a front view of the ladder of Figure 1, with a latch in a hold position;

[0015] Figure 4(a) is a close view of the latch from Figure 4;

[0016] Figure 5 is a front view of the ladder of Figure 1, with the latch in a release position;

[0017] Figure 5(a) is a close view of the latch from Figure 5.

[0018] Figure 6 is a rear view of the ladder of Figure 1, showing a control means; and [0019] Figure 6(a) is a partially cut away view of the control means from Figure 6.

Detailed Description of Preferred Embodiments [0020] Referring to the Figures, there is shown a body 10 of a vehicle, such as a loader, including hand rails 12. A ladder assembly 20 is fixed to the vehicle body 10.

[0021] The ladder assembly 20 has a frame 22. The frame 22 has two vertical posts 24, which are spaced apart by a plurality of fixed rungs 26. The frame 22 includes two generally U-shaped brackets 28 having side arms 30 and a rear bar 32. The side arms 30 are each fixed to respective vertical posts 24. The rear bar 32 is fixed to the vehicle body 10.

[0022] Each of the vertical posts 24 has three forwardly projecting flanges: an upper flange 34, a middle flange 36 and a lowerflange 38. A track member 40 is associated with each vertical post 24, being supported by the forwardly projecting flanges 34, 36, 38. The arrangement is such that each track

2018101227 24 Aug 2018 member 40 is parallel to, and forwardly spaced from, its associated vertical post 24.

[0023] A moveable track 42 is mounted around each track member 40. The moveable tracks 42 are generally H-shaped in cross section, and each is arranged to locate on an inner side of its track member 40. The moveable tracks 42 includes rollers (not shown) to allow each moveable track to easily move along (that is, up and down) its associated track member 40.

[0024] The moveable tracks 42 are constrained to move relative to the track members 40 between a first position whereby an upper end of the moveable track 42 is located within the upper forwardly projecting flange 34, and a second position whereby the upper end of the moveable track 42 is located within the middle forwardly projecting flange 36.

[0025] A ladder extension portion 50 is located on the moveable tracks 42.

[0026] The ladder extension portion 50 has two side walls 52, and a plurality of rungs 54 extending between the side walls 52.

[0027] The side walls 52 are arranged to locate within the inner sides of the moveable tracks 42. The moveable tracks 42 include rollers (not shown) to allow each side wall 52 to easily move along (that is, up and down) its associated moveable track 42.

[0028] The side walls 52 are constrained to move relative to the track members 40 between a raised position whereby an upper end of the side wall 52 is located within the upper forwardly projecting flange 34, and a lowered position whereby the upper end of the side wall 52 is located within the lower forwardly projecting flange 38.

[0029] It will be appreciated that the ladder extension portion 50 is moveable between three positions: a stowed position whereby the ladder extension portion is within the frame 22; an intermediate position whereby the moveable

2018101227 24 Aug 2018 tracks 42 have moved to their second position but the ladder extension portion 50 has not moved relative to the moveable tracks 42; and a deployed position where the moveable tracks 42 are in their second position and the ladder extension portion is in its lowered position.

[0030] The ladder assembly 20 has a latching assembly 60 as is shown in Figures 4 and 5.

[0031] The ladder extension portion 50 has an internally projecting lateral detent 62. The lateral detent 62 extends from one side wall 52 generally towards the other side wall 52. The lateral detent 62 is arranged to rest atop a catch 64 when the ladder extension portion is in its stowed position.

[0032] The catch 64 is formed from sheet material, oriented in a plane perpendicular to the direction of the rungs 54. The catch 64 has an upper portion 66 which is generally right-triangular in shape, and a lower portion 68 which is generally elongate. The arrangement is such that the lower portion 68 is effectively an extension of a side of the triangular shape of the upper portion 66. The upper portion 66 of the catch 64 thus has an upper surface 70 which is generally horizontal when in its hold position as shown in Figure 4; and an under surface 72 which is oriented at about 45° relative to the vertical. The catch 64 is arranged to pivot about a lateral pivot point 74, located within the lower portion 68.

[0033] The latching assembly 60 is mounted to an upper U-shaped bracket 28. The latching assembly 60 includes a pivot rod 80, which is parallel to the fixed rungs 26, and extends from a first end within the frame 22 to a second end outside the frame 22. A handle 82 is mounted to the second end of the pivot rod 80, such that movement of the handle 82 causes rotation of the pivot rod 80 along its axis.

[0034] Two linkages 84 extend between the first end of the pivot rod 80 and the upper portion 66 of the catch 64. The arrangement is such that rotation of the handle 82 in a direction towards the vehicle body 10 is transferred through

2018101227 24 Aug 2018 the linkages 84 to result in rotation of the catch 64 about the pivot point 74, in a direction towards the vehicle body. This moves the catch 64 into the release position shown in Figure 5.

[0035] A spring 86 and a stop 88 are provided to bias the catch 64 into its hold position.

[0036] The ladder assembly 20 also includes a control means arranged to allow relatively slow release of the ladder extension portion 50 from its stowed position into its deployed position. This control means includes a toothed bar 90 which is fixed to one of the side walls 52 of the latter extension portion 50.

[0037] The frame 22 includes a housing 92 located at a lower end of one vertical post 24, corresponding to the side wall 52 on which the toothed bar 90 is positioned. Within the housing 92 is located a toothed wheel 94. The toothed wheel 94 has a radial damper associated with it, such as a radial damper sold under the trade mark DICTATOR.

[0038] The toothed wheel 94 is arranged to engage with the toothed bar 90 in a rack-and-pinion style arrangement. The radial damper associated with the toothed wheel 94 acts as a brake on the toothed bar 90, and thus on the ladder extension portion 50.

[0039] The radial damper is arranged for a one-way operation, such that it applies a braking action to the toothed bar as it descends, but not when it is moved upwards.

[0040] When deployment of the ladder assembly 20 from its stowed position is required, the handle 82 is pushed towards the vehicle body 10. This causes movement of the catch 64 into its release position, in which the upper surface 70 of the upper portion 66 moves towards the vehicle body 10 and releases the lateral detent 62.

2018101227 24 Aug 2018 [0041] With the release of the lateral detent 62 gravity is able to act on the ladder extension portion 50, causing it to move into its deployed position. Under the action of the radial damper, this movement is relatively slow and controlled, greatly reducing entrapment or impact risks to the user or to others in the vicinity.

[0042] When a user wishes to stow the ladder extension portion 50, this can be done simply by pushing up on the lowest-most rung 54. The ladder extension portion 50 can be raised without impediment by the radial damper. When the lateral detent 62 reaches the catch 64, the action of the lateral detent 62 on the under surface 72 causes the catch 64 to pivot until the detent 62 has passed. At that point the bias of the spring returns the catch 64 to its hold position beneath the lateral detent 62.

[0043] It will be appreciated that while the ladder assembly 20 is connected to a vehicle bodylO in this embodiment, it could readily be connected to a different base surface.

[0044] Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.

2018101227 24 Aug 2018

Claims (5)

1. Claims

   1. An emergency access ladder, the ladder having a frame for fixed attachment to a base surface, the frame including at least one fixed rung, the ladder including a moveable track connected to the frame and constrained to move in a vertical direction relative to the frame, the ladder also including a ladder extension portion having at least one rung, the ladder extension portion being connected to the moveable track and being constrained to move in a vertical direction relative to the moveable track; wherein the frame includes a latch moveable between a hold position in which it restricts downward movement of the ladder extension portion and a release position in which it permits downward movement of the ladder extension portion.
2. 2. An emergency access ladder as claimed in claim 1, wherein the latch is biased into the hold position.
3. 3. An emergency access ladder as claimed in claim 1 or claim 2, wherein the latch has an associated handle which can be operated to move the latch into the release position.
4. 4. An emergency access ladder as claimed in any preceding claim, wherein the ladder extension portion includes a means to control the rate of downward movement.
5. 5. An emergency access ladder as claimed in any preceding claim, wherein the base surface is part of a vehicle.

   BEND-TECH INVESTMENTS 1 PTY LTD

   By its Patent Attorneys

   ARMOUR IP

   P2284AU01

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