FR2675196A1 - EMERGENCY LADDER WITH BUILT-IN ELEVATOR. - Google Patents

Abstract

To allow motor-driven hoisting to the top of the leg of a crane while providing an emergency ladder with good safety characteristics, the crane leg is provided with a ladder (20) having a safety loop (30) (with a size of preferably no more than one metre) inside which a lift cage (40) can travel up and down the ladder, preferably by means of a rack (26) supported by the ladder. The ladder with its rack is preferably mounted on the crane leg with a certain degree of freedom to slide vertically.

Description

EMERGENCY LADDER WITH INCORPORATED ELEVATOR
The invention relates to elevators traveling along guide masts acting as an emergency ladder. Such structures are found in tower cranes, tall gantries, chimneys, mine shafts, antennas, radio relay stations, water towers, bridge piers, steel frame towers, oil platforms etc .... The invention will be described for a tower crane mast, but it is obvious that the use of the invention is possible in other fields. With a crane or for the other fields mentioned, the mast is the vertical metallic structure which supports at its top a device, for example a horizontal boom used to transport materials, objects or another device.

 To access the summit, for example in the case of a tower crane whose driver must be able to reach the control cabin, the mast can be fitted with a ladder or an elevator.

 When the means of access is a ladder, the regulations require that this ladder is surrounded by a crinoline, that is to say a trellis cage, the dimensions of which are such that they prevent the fall of a person on a great height; by falling, the person strikes the walls of the cage and can hang on to the bars of the cage.

 Typically, a crinoline has dimensions of the order of 75 cm side or less.

 Sometimes, to avoid a crinoline, the ladder is arranged not outside but inside the mast, and it is oriented not vertically but obliquely: it goes up in a zig-zag inside the mast with stages at each change of direction. Without being a real crinoline, the crane mast serves as a sort of protective cage.

 When an elevator is provided, it is always outside the crane mast; an emergency ladder can also be provided, in case the elevator is blocked. It is near the elevator and surrounded or not by a crinoline; if it is surrounded by a crinoline, it is dangerous to access the ladder from an elevator blocked at height; if it is not surrounded by a crinoline, it presents the dangers inherent in any scale without crinoline.

 The invention aims to improve the ease and security of access in the upper parts of cranes or gantries, or any other access at height.

 The present invention provides a mast construction in which an elevator runs along a ladder, inside a ladder safety crinoline. By ladder crinoline is meant here not any cage surrounding the elevator, but a protective cage against falls by people, therefore having reduced dimensions making it possible to avoid such a fall; these dimensions are therefore less than about 1 m side or even less (preferably about 80 cm side).

 We thus obtain a possibility of normal hoisting using a small elevator (for one or two people) and a rescue ladder for cases where the elevator is broken or blocked in height.

 With the invention, if the elevator is broken, the user can get out and he is already inside the crinoline of the ladder.

 The ladder in practice serves as a guide for the elevator car; preferably the ladder carries a rack in which is meshed with a drive pinion of a motor carried by the elevator car.

 According to an improvement, the interior of the cabin comprises ladder bars which are in correspondence with the bars of the crinoline ladder; thus, to exit the cabin by a hatch on the ceiling or by a hatch in the floor, the user will use these interior ladder bars which ensure a scale continuity between the interior and the exterior of the cabin. Even supposing that the cabin is blocked at a certain height, the user can always climb to the top of the mast by the emergency ladder, crossing the immobilized cabin, without losing the continuity of the ladder. The internal bars are preferably arranged with the same pitch as those of the external ladder, but it will be understood that this is not compulsory. In any case, the internal bars of the cabin must be located on that of the sides of the cabin sliding along 11 emergency ladders.

 According to another improvement, very important in the case of masts formed of elements placed end-to-end, and containing elements of ladder placed end-to-end, the ladder carrying a rack is fixed to the crane mast with a degree of freedom of sliding along the axis of the mast (in principle vertical). In this way, the scale is not integral with the deformations of the mast, nor with the differences in dimensions between mast elements and scale elements; the different scale portions always rest directly on each other. This is important because of the need to have very precise continuity of the rack elements carried by the ladder, from one section of ladder to another. Any discontinuity causes very significant wear of the pinion or rack teeth, or even the risk of breakage.

 It should be understood that the ladder will be made like the crane mast by successive sections superimposed.

 The ladder is therefore preferably maintained along one side of the mast by lugs which hold it against horizontal movements while allowing longitudinal movement along the axis of the mast.

 The ladder has two lateral uprights, one of which preferably has a U-shaped profile and the other (the one carrying the rack) preferably has an L-shaped profile (to facilitate the fixing of the rack to the 'ladder). Guide rollers mounted on the cabin are supported on these profiles to ensure the maintenance in place of the cabin, the movement thereof without friction, and the maintenance of the drive pinion in firm support against the rack.

Other characteristics and advantages of the invention will appear on reading the detailed description which follows and which is given with reference to the accompanying drawings in which
- Figure 1 shows a general view of a crane mast portion according to the invention;
- Figure 2 shows a top view of this mast portion;
- Figure 3 shows an enlarged view of the elevator car circulating in the crinoline of the ladder;
- Figure 4 shows a partially exploded view showing the interior of the elevator car;
- Figure 5 shows a detailed top view of the ladder and the pinions and guide rollers of the elevator car;
- Figures 6a to 6c show a use of the cabin with curved ladders
- Figure 7 shows a sliding detail.

 In Figure 1, we see in side view a portion 10 of tower crane mast; its general structure is a classic vertical metal structure with a square or rectangular section. In the figure, which is a side view, we see two of the four vertical uprights 12 which constitute the frame of the mast. Horizontal and / or oblique crosspieces 14, 16 complete the structure.

 Inside the mast is provided according to the invention a vertical ladder 20 of which we can see the vertical uprights 22 and the horizontal bars 24. This ladder rests against one side of the mast, here, the side visible in FIG. 1.

 The ladder is surrounded by a safety crinoline, which is designated by the reference 30 and of which there has been shown in FIG. 1 only two vertical uprights on either side of the ladder.

 This crinoline has the structure and dimensions of a real ladder safety crinoline: it is a cage with bars completely surrounding the ladder except possibly on the side where the ladder rests on the mast, if however the structure mast is dense enough to play the role of one side of the crinoline. The dimensions of the cage are preferably of the order of 80 cm per side. In any case, the crinoline can hardly exceed a meter on one side.

 Inside the ladder safety crinoline there is an elevator cabin 40. This cabin is guided by the ladder; it is preferably driven by a motor carried by the cabin itself.

This motor drives a drive pinion which meshes in the teeth of a rack which is preferably fixed on the scale itself. The engine is an electric motor powered by a cable which descends under the cabin while remaining inside the safety crinoline.

 With regard to this cable, it will be noted that the invention solves the problem that is generally encountered for lifts or lifting platforms of external construction sites: these lifts circulate outside and not inside a mast of hoisting, and the cable swings under the action of the wind with an amplitude such that it is generally necessary to provide cable guidance and retaining systems. These systems hinder the free movement of the lift and do not always work well.

 With the system of the invention, it will suffice to have a cable receptacle under the cabin, inside the crinoline; this receptacle will be a simple cylindrical barrel with possibly inside the barrel a cone facilitating the winding of the cable during the descent. The crinoline will be used as a cable guide over the entire height of the crane.

 FIG. 2 represents a top view corresponding to FIG. 1.

 In Figure 3, there is shown in a more enlarged view the elevator car inside the crinoline of the ladder. The crane mast has not been shown, for the sake of simplification of the representation. It should be understood that the crinoline is fixed either on the mast directly or on fasteners placed regularly along the height of the mast and fixed to the mast.

 The crinoline 30 comprises for example four vertical uprights 32 and horizontal bars 34.

In the example shown, the crinoline completely surrounds the ladder 20 and therefore has four sides; its horizontal section is substantially square; it could be rectangular, or even circular.

The spacing between horizontal bars of the crinoline can for example be of the order of 50 cm.

 The ladder 20 is pressed against one side of the crinoline. We will see later that it is preferable that it is not completely integral with the crinoline and the mast. It is preferably left with a degree of freedom of sliding in the vertical direction.

But it is held against the crinoline in the horizontal direction. In some cases, the crinoline can be replaced by a safety rail commonly called lifeline. In this case, a harness is provided in the cabin.

 Along one side of the ladder 20 is fixed a rack 26, that is to say a vertical toothed bar which extends over the entire height of the ladder.

 The elevator car 40 is driven in vertical movement up or down using an electric motor or geared motor 42 which rotates a toothed pinion 44; the pinion meshes with the rack and therefore has a toothing the same as this one.

 For example, the engine is mounted on the roof of the cabin. It is supplied with electricity by a cable 46 already mentioned, which passes in the cabin and which descends below it in the crinoline.

 The cabin 40 preferably has a lower emergency hatch opening in its floor and an upper emergency hatch opening in its ceiling.

 The upper emergency hatch is visible in FIG. 3 and is designated by the reference 48.

 The elevator also has a side door, not visible in the figures. At the bottom and top of the crane and possibly at various locations spaced along the crane, openings can be made in the crinoline to form exit passages in correspondence with the elevator door. However, these passages are not compulsory, and it can be foreseen that the normal exit mode of the elevator is the passage through the upper exit hatch.

 Moreover, according to a preferred embodiment of the invention, the interior of the cabin 40 is provided with ladder bars; these bars make it possible not only to access the upper hatch but also to enter and exit by the upper hatch or the lower hatch by using both these bars and the bars of the ladder 20 along which the cabin circulates. Thus, the continuity of the ladder is established through the interior of the elevator car regardless of the position of the car in the crane mast.

 FIG. 4 represents a partially exploded view of the cabin 40, with internal bars 50 situated on the cabin wall which is placed against the ladder 20. The upper hatch is shown open, without closing cover, so that one can see the internal bars 50. The crinoline 30 has not been shown in this figure.

 It will be understood that this continuity of scale makes it possible, when the two hatches of the cabin are open, to pass through the cabin if the latter is broken down.

 The elevator car is conventionally provided with automatic braking means (not shown), compulsory in any elevator system.

 In Figure 5, the preferred way of holding the ladder in the crane mast is shown. FIG. 5 is a top view of the ladder 20, of its fixing, and of the connection mechanisms between the ladder and the elevator car 40.

 The crane mast is not shown precisely in FIG. 5 but the reference 60 designates a bar secured to the crane mast and which will be used to maintain the ladder and moreover also its crinoline. Such a bar is provided from place to place along the height of the mast to hold the ladder and the crinoline from place to place.

 It is particularly advantageous that the ladder remains free to slide vertically. This is why provision is made, for example, for the ladder to comprise two vertical uprights 62 and 64 having shapes of profiles such that they can be retained by lugs 66, 68 fixed to the bars 60. It can be seen in FIG. 5 that the legs 66 and 68 prevent the horizontal movements of the ladder without preventing its vertical movements.

 The horizontal bars 24 of the ladder extend between the uprights 62 and 64.

 Furthermore, the vertical uprights of the ladder are also profiled so as to serve as raceways for rollers which guide the elevator car in its vertical movement.

 Finally, one of the uprights, here the upright 64 is profiled so that the rack 26 can be attached to it with which the drive pinion 44 driven by the motor 42 cooperates.

 In the preferred example shown, the upright 62 is U-shaped. The bars of the U are parallel to the bars of the ladder; the U bar which is closest to the bar 60, and which is designated by 621 is retained by the tab 66; the one which is farthest, 622, serves as a raceway for guide rollers 70 and 72, carried by a support 74 secured to the elevator car. The rollers 70 and 72 are supported for example each on a respective face of the bar 622. These rollers allow the rolling without friction of the elevator along the scale; they prevent any movement of the cabin perpendicular to the general plane of the ladder.

 Other rollers integral with the cabin could bear, for example on the central bar of the U to prevent horizontal movements in the plane of the ladder. They are not represented.

 Furthermore, it should be understood that several rollers such as 70 and 72 can be superimposed, for example a torque 70, 72 at the top of the elevator car, and another at the bottom.

The other amount of the ladder, 64, is preferably an L-shaped section. One of the bars of the L, similar to the bar 621 of the U, is retained by the lug 68. The bars of the ladder are stretch between the other bar of the
L and the central bar of the U. This other bar of the L is used to support the rack 26.

 The rack 26 is for example bolted every 20 cm to the upright 64, at the end of the bar of the L. The teeth of the rack are here turned towards the cabin taking into account the position and the orientation of the pinion d attack 44, but other arrangements could be considered. The rear of the rack 26 (on the other side of the teeth) can serve as a raceway for a reaction roller 76 which has the function of preventing the drive pinion 44 from coming out of the teeth of the rack.

 The pinion 46 and the roller 76 are therefore mounted on the same plate 78 at a fixed distance from each other and with little play over this distance.

 Again, other guide rollers can be provided and mounted for example at the bottom of the cabin.

The reason why it is preferred that the ladder is mounted with a degree of freedom of vertical sliding is as follows
In principle, the crane masts are assembled in overlapping pieces and bolted to each other. They will include the necessary crinoline and ladder elements, and of course the rack fixed on the ladder.

 When there is wind or any other cause of deformation of the crane mast, the mast elements play relative to each other; the ladder elements could tend to disjoin if they were each secured to a respective mast element. And then, the corresponding rack elements would no longer be contiguous. This is very dangerous because it causes a risk of breakage (and in any case very significant wear) of the rack teeth or of the teeth of the drive pinion when the latter passes over an area where the pitch of the rack is not more exactly what it should.

 By leaving the ladder free, the ladder elements rest on each other by their own weight and this regardless of the deformations of the mast elements with which they are no longer integral.

 If the mast elements have imprecise heights, which is inevitable, there is moreover no risk of lack of continuity of the pitch of the rack.

 When assembling the crane mast elements one above the other, the ladder and crinoline elements are in place inside the mast elements. The ladder is then preferably prevented from sliding vertically relative to the mast, this thanks to a temporary fixing. For example, a pin 80 passes horizontally through two holes 82 and 84 facing each other, one in an upright (64 for example) of the ladder and the other in the fixing lug (68 ) who retains this amount. The pin may also pass through the bar 60. This pin is removed as soon as the mast element which carries it has been fixed to the crane. The ladder then falls by a few centimeters at most to come to rest on the next lower ladder element.

 The ladder elements are the same length as the mast elements, or of submultiple length.

 It can be expected that the elevator car is made up of several floors, with hatches to communicate between these floors. The cabin can be modular, with a standard element carrying the drive mechanism and variable elements according to needs to constitute the passenger cabin itself.

 The cabin can be fitted with a false ceiling, if it is preferred that the engine remains inside; the engine is then placed on the false ceiling. There could also be a raised floor, the engine being under the raised floor.

 The ladder crinoline can be fitted with retractable rest bearings, which are plates mounted on hinges and which can be folded down either in the storage position (vertical) so as not to impede the passage of the cabin, or in the position of use (horizontal). The user can rest on these plates if necessary, by folding them in a horizontal position. There can be, for example, every 10 meters.

 Since the elevator car occupies practically all the space available inside the crinoline, with the exception of the space occupied by the ladder, various means can be provided to prevent the car from getting stuck in case of deformation of the crinoline.

 For example, the edges of the cabin are bevelled.

 Also, the crinoline can be provided with sensitive bars, capable of controlling the stopping of the engine of the cabin, these bars being mounted on the crinoline in the immediate vicinity of the passage of the cabin and being found in its passage in the event of excessive deformation of crinoline. The bars can also be mounted on the cabin and be activated if they hit the crinoline in the event of its deformation.

 In another improvement, the cabin can be suspended from a carriage 90 by means of a pin 91 (FIG. 6c). This provision allows the installation of an elevator in a section with non-constant alignment (atmospheric refrigerant or mine shaft for example). The section is thus curved downwards then straight upwards (Figure 6b). In this case, the bottom of the cabin 40 can also be held against the ladder 22 by a lower carriage (not shown). The carriage 90 then preferably carries the gearmotor 42 as well as a parachute device 92 which is opposite it opposite, so that the two pinions are as close as possible to each other to favor the taking of curve. In practice, with pinions 4 cm in radius, a clearance of about 2 mm is left between these pinions. This play should not exceed 10 cm. Given the size of the device 92 of the parachute and the size of the motor 42, it has in fact been found that placing these devices 92 and 42 on either side of the rack made it possible to bring the pinions together.

 The U-shaped profile of the upright 62 can be replaced by a special profile shown in Figure 7 where one of the branches of the U, instead of being flat, has a hollow shape. The rollers 721 and 722, the profiles of which are adapted to this hollow shape are supported there. They then prevent movement of the cabin, or the carriage, in any direction contained in a plane perpendicular to the plane of the ladder.

Claims (12)

 1. Ladder (20) emergency (30), characterized in that it comprises an elevator car (40) running in support along the ladder.  2. Ladder according to claim 1, characterized in that it comprises a crinoline inside which circulates the elevator.  3. Ladder according to claim 1 or claim 2, characterized in that it carries a rack (26) in which comes to mesh a drive pinion (44) of a motor carried by the elevator car.  4. Ladder according to one of claims 1 to 3, characterized in that it is fixed to a crane mast with a degree of freedom of sliding along the axis of the mast.  5. Ladder according to one of claims 1 to 4, characterized in that the interior of the cabin comprises ladder bars (50) which are in correspondence with the bars of the crinoline ladder.  6. Ladder according to one of claims 1 to 5, characterized in that the ladder has two lateral uprights, one of which (62) has a shape of a U-shaped profile and the other (64) a shape of a shaped profile. L.  7. Ladder according to claim 6, characterized in that guide rollers (70, 72, 76) mounted on the cabin bear on the profiles to ensure the holding in place of the cabin, the movement thereof without friction , and maintaining the drive pinion in firm support against the rack.  8. Ladder according to one of claims 6 to 7, characterized in that it is provided with fixing lugs (66, 68) integral with the crane mast and shaped so as to retain the amounts of the ladder against a horizontal movement and allow it to slide vertically.  9. Ladder according to one of claims 1 to 8, characterized in that the elevator car is provided with an exit hatch at the top and / or an exit hatch at the bottom.  10. Ladder according to one of claims 1 to 9, characterized in that the cabin is held against the ladder by means of an axis (91) which links it to a carriage (90).  11. Ladder according to one of claims 1 to 8, characterized in that it comprises a motor unit and a parachute provided with reduction gears sufficiently close to each other to be able to adapt to breaks and / or within a radius of curvature of the ladder, the motor and the parachute being placed on either side of the rack on which the pinions mesh.  12. Use of the ladder according to any one of claims 1 to 11 in gantries, chimneys, refrigerants, machines, antennas, radio relay stations, water towers, bridge piers, towers in steel frame, oil platforms, or mine shafts.