WO1996034171A1

WO1996034171A1 - Ladder ramp

Info

Publication number: WO1996034171A1
Application number: PCT/NO1996/000095
Authority: WO
Inventors: Hans Heggen; Alf Skoglund
Original assignee: Raufoss Stigen A/S
Priority date: 1995-04-28
Filing date: 1996-04-24
Publication date: 1996-10-31
Also published as: NO951656L; NO300513B1; EP0821759A1; AU5660896A; NO951656D0

Abstract

A ladder ramp designed for the rapid lowering of a ladder lying on the ramp (5) in ready position is shown. The ramp (5) comprises a swing frame (4) pivotably connected to a support or a base (2), at least one damper means (3) for the swinging movement operative between the base (2) and the swing frame (4), a slide frame (1) lying in the swing frame (4) and capable of sliding along said swing frame (4), at least one damper means (7) for the sliding movement operative between the slide frame (1) and the swing frame (4), a releasable locking device (15) which holds the slide frame (1) in a position of readiness at the starting position, which slide frame (1) forms an angle of inclination (α) with the base (2) and stands in a gravity-actuable state of readiness and, after the release of the locking device, following a predetermined sliding movement, undergoes a tipping/pivotal movement. The tipping movement stops at a predetermined angle corresponding to a certain height above ground for the lower end of the ladder where this end of the ladder may be grasped by personnel at hand level. The slide frame includes elongate, continuous guide means for engagement with guide means on the upper end of the ladder, as said personnel who have grasped the lower end of the ladder begin to transport the ladder away from the slide frame while the upper end is moved downward along the slide frame in the guide means until the upper end is at hand level to be grasped and transported away by additional personnel.

Description

LADDER RAMP

The present invention relates to a ladder ramp designed for the rapid lowering of a ladder lying on the ramp in ready position, which ramp comprises a swing frame pivotably connected to a support or base, at least one damper means for the swinging movement operative between the base and the swing frame, a slide frame lying in the swing frame and capable of sliding along said swing frame, at least one damper means for the sliding movement operative between the slide frame and the swing frame, a releasable locking device which holds the slide frame in a state of readiness at the starting position, which slide frame forms an angle of inclination with the base and stands in a gravity-actuable state of readiness and, after the release of the locking device, following a predetermined sliding movement, undergoes a tipping/pivotal movement.

This type of ladder ramp is designed particularly for rescue purposes, e.g., in the area of life-saving service, such as on a fire truck. The ladder ramp conceivably could also be used in buildings to maintain preparedness in case an emergency situation should arise. As noted earlier, the present ladder ramp has been developed with a view toward rescue operations wherein the time required to rig equipment in place may be of utmost importance. Hence there will always be a demand for tools capable of bringing rescue equipment from a position of readiness to an operative position with ever-increasing speed. It is desirable that this should be done as automatically as possible, i.e. , with an absolute minimum of manual operations.

From Norwegian laid-open patent application no. 169734 there is known a ladder ramp of the type introduced above. Typical for this ladder ramp is the feature that the ladder is brought from a state of readiness on the vehicle to an inclined position behind the vehicle, after which a crew must lift the entire ladder out of the swing frame and the slide frame. It is not uncommon that there are four ladders lying on top of one another in ready position, thus having a considerable weight. Normally, four persons would be required to carry such a ladder set from the vehicle to the place of use. To facilitate this operation whereby the crew is to lift the ladder set out of the slide frame, there have been made some additional improvements on the equipment shown in this earlier publication. What one would now like to achieve is to bring the lower end of the ladder set down to a specific height that conforms to the hand level of the personnel, enabling them easily to grasp the lower part of the ladder. Subsequently the opposite end, or the upper end, is brought down along the slide frame until this end, as well, reaches the hand level of the crew so that the ladder may be easily gripped by additional persons and transported away from the location.

This is achieved with a ladder ramp of the type introduced above, which is characterized in that the tipping movement stops at a predetermined angle corresponding to a predetermined height above ground for the lower end of the ladder where this end of the ladder may be grasped by personnel at hand level, that the slide frame comprises elongate, continuous guide means for engagement with the guide means at the upper end of the ladder, as said personnel who have grasped the lower end of the ladder start to transport it away from the slide frame while the upper end is being guided down the slide frame in the guide means until the upper end is at hand level to be grasped and transported away by additional personnel .

Advantageously the elongate, continuous guide means may consist of rails having a ^'-shaped profile. The guide means on the upper end of the ladder may be rollers or wheels which run in the elongate guide means on the slide frame. Further, the elongate guide means may be adjustable in the transverse direction toward and away from each other.

The slide frame itself may constitute a ladder whereby, after lowering the ladder ramp, the crew may, for example, climb up on a rescue vehicle to fetch equipment.

The swing frame may be attached directly to the vehicle or to the base, but it may be advantageous to include a base frame which in turn is attached to the base.

The slide frame forms an angle of inclination with the base or the base frame in the ready position. This facilitates the lowering of the ladder, which will take place almost automatically with the aid of the actual weight of the ladder and the slide frame together with the displacement of their center of gravity. To further reduce the friction between the slide frame and the swing frame, said swing frame may advantageously be provided with rollers cooperating with the slide frame or the side members thereof.

The various damper means may consist of gas springs, gas cushions or conventional shock absorbers.

Other additional objectives, features and advantages will be apparent from the following specification of a presently preferred embodiment of the invention provided for the purpose of description, without thereby being restrictive, and provided in connection with the enclosed drawings, where:

Figures la-lc are schematic illustrations of a side view of the ladder ramp according to the invention, mounted on a vehicle and in three different positions during the imagined lowering of a ladder (the ladder itself is not shown),

Figures 2a-2c are schematic illustrations of a top view of the ladder ramp according to Figures la-lc in the same positions as in Figure 1, and

Figure 3a is a schematic illustration of a section transverse to the longitudinal direction of the ladder ramp at the level of the support wheel at the upper end of the ladder ramp,

Figure 3b is a schematic illustration of a transverse section through the ladder ramp at the level of the forward roller on the swing frame,

Figure 3c is a schematic illustration of a transverse section at the level of the rear roller on the swing frame.

Reference is made to Figures la-lc showing a rescue vehicle forming a base 2 for a ladder ramp 5 mounted on the roof of the vehicle. A ladder (not shown) or a ladder set consisting of up to four or five individual ladders is intended to lie in ready position atop the actual ladder ramp 5. A ladder set of this type could be of considerable weight, e.g., 150 kilos. Hence, the presence of several persons would be required to carry the set of ladders away from the vehicle and to the place of usage. When the ladder is not in use it will lie in the ladder ramp 5 in a position of readiness on top of the vehicle. The ladder ramp 5 comprises a swing ramp 4 pivotably connected to a base 2, which itself could well be a vehicle, or any type of stationary support serving to store and maintain a ladder set in a state of readiness. Ladder ramp 5 may include a base frame 2b that is attached to the base 2 itself. Swing frame 4 is pivotably connected to base frame 2b by means of an axle 10. At the opposite end of axle 10 are one or more damper means 3 operative between base frame 2b and swing frame 4. The damper means 3 have an attenuating or damping effect on the swinging movement of frame 4 when it swings up and pivots about axle 10. Further, it prevents swing frame 4 from executing an angular movement beyond a predetermined angular inclination such as that indicated in Figure lc. This has been adapted to bring the lower end 12 approximately to hand level for grasping of the ladder set by personnel at a suitable height. There is also included a damper means 7 which restricts the sliding movement between slide frame 1 and swing frame 4. Slide frame 1 runs easily its own longitudinal direction with the aid of rollers 9, 9b permanently mounted on swing frame 4. Also, slide frame 1 is provided at the upper end thereof with support wheels 8 which roll for a certain distance along base 2. There is further included a locking device which may be released and which thereby allows slide frame 1 to begin to move relative to base 2. In the motion of lowering the ladder, when the center of gravity for ladder ramp 5 and the ladder set moves past axle 10, the ladder ramp 5 will undergo a pivotal or tipping movement about axle 10, and support wheel 8 will lift up from base 2, as swing frame 4 and slide frame 1 undergo a tipping movement in relation to base 2. Damper means 3 will to a certain extent prohibit a further tipping movement.

Figures 2a-2c show the positions corresponding to la-lc viewed from the top. As is clearly apparent from these figures, ladder ramp 5 comprises elongate, continuous guide means 6, here in the form of rails, designed to carry guide means, e.g., in the form of wheels, provided on the ladder set. These are brought into function when ladder ramp 5 has been swung down to its lowered position and the personnel have taken hold of the ladder set at the lower end thereof and will be pulling the rest of the ladder set with them, down to the grasping level. Ladder ramp 5 thus serves as a downwardly inclined plane for the upper end of the ladder set, which then is guided by means of rollers in the guide rails 6 down to the lower end 12 of ladder ramp 5, where still another personnel team may grasp the other end of the ladder set and lift it up and out of ramp 5 and transport it away. In this manner, a convenient lifting height has been obtained for both the first and the second team of personnel, at the same time as a finely tuned distribution of weight is afforded during the entire lowering operation. Figure 3a shows a section through ladder ramp 5 at the level of support wheel 8. Here is also shown a support wheel 14 which is mounted on the ladder set. These wheels may be substituted with gliders or slide pads, for example, although wheels would be a practical means.

Figure 3b shows a section through ladder ramp 5 at the level of the front wheel set 9. As is apparent, the elongate, continuous guide rails 6 are adjustable by means of screws 11 toward and away from each other as required or desired.

Figure 3c shows a corresponding section at the level of the rear pair of the wheel 9b and thus near the pivot axle 10 of ladder ramp 5.

As is apparent from Figures 1 and 2, there are also included damper means 7 operative between swing frame 4 and slide frame 1 to suppress the movement of slide frame 1 in relation to swing frame 4 when slide frame 1 approaches its end position. The sliding movement is initiated as a result of the angle α between the base 2 and the horizontal plane.

Claims

P a t e n t C l a i m s

1.

A ladder ramp designed for the rapid lowering of a ladder lying on the ramp (5) in ready position, which ramp (5) comprises a swing frame (4) pivotably connected to a support or base (2), at least one damper means (3) for the swinging movement operative between the base (2) and the swing frame (4), a slide frame (1) lying in the swing frame (4) and capable of sliding along said swing frame (4), at least one damper means (7) for the sliding movement operative between the slide frame (1) and the swing frame (4), a releasable locking device which holds the slide frame (1) in a state of readiness at the starting position, which slide frame (1) forms an angle of inclination ( ) with the base (2) and stands in a gravity-actuable state of readiness and, after the release of the locking device, following a predetermined sliding movement, undergoes a tipping/pivotal movement, c h a r a c t e r i z e d i n that the tipping movement stops at a predetermined angle (p) corresponding to a certain height above the ground for the lower end (12) of the ladder where this lower end (12) of the ladder may be grasped by personnel at hand level, that the slide frame (1) comprises elongate, continuous guide means (6) for engagement with guide means (14) on the upper end of the ladder, as said personnel who have grasped the lower end (12) of the ladder transport the ladder away from the slide frame (1) while the upper end of the ladder moves downward along the slide frame (1 ) in the guide means (6) until the upper end is at hand level for to be grasped and transported away by additional personnel.

2.

A ladder ramp in accordance with claim 1 , c h a r a c t e r i z e d i n that the elongate, continuous guide means (6) are rails having a U-shaped profile.

3.

A ladder ramp in accordance with claim 1 or 2 , c h a r a c t e r i z e d i n that the guide means on the upper end of the ladder are pads, rollers or wheels (14) which run in the elongate guide means (6) on the slide frame (1).

4.

A ladder ramp in accordance with one of the claims 1 to 3 , c h a r a c t e r i z e d i n that the elongate guide means (6) are adjustable in a transverse direction toward and away from each other.

5.

A ladder ramp in accordance with one of the claims 1 to 4 , c h a r a c t e r i z e d i n that the slide frame (1) itself constitutes the ladder.

6.

A ladder ramp in accordance with one of the claims 1 to 5 , c h a r a c t e r i z e d i n that the base or support (2) is a base frame (2b).

7.

A ladder ramp in accordance with claims 1 to 6 , c h a r a c t e r i z e d i n that the swing frame (4) is equipped with rollers (9) cooperating with the slide frame (1).

8. A ladder ramp in accordance with claims 1 to 7 , c h a r a c t e r i z e d i n that the damper means (3, 7) comprises a gas spring, gas cushion or conventional shock absorber.