GB2182909A - A device for vertically adjusting the upright axis of a superstructure turnably and inclinably mounted on an understructure - Google Patents

Abstract

A device (1) for vertically adjusting the upright axis (2) of a superstructure (4) - for example a rescue appliance on a turntable ladder (5) - turnably and inclinably mounted on an understructure (3) comprises two superposed compensators (6, 7) which are shaped like conical rings, are disposed between the turntable superstructure (4) and the understructure (3) and are rotatable in the same or in opposite directions. A first rotary drive unit (8) fastened to the understructure drives via a first pinion (9) a first annular gear (10) of the lower rotatable compensator (7) while a second rotary drive unit (11) fastened to the superstructure drives via a second pinion (12) a second annular gear (13) of the upper rotatable compensator (6). The upper compensator (6) is also provided with a third rotary drive unit (14) fastened to the understructure and driving this compensator via a third pinion (15) in direct mesh with a third annular gear (17) of this upper compensator (6). The third pinion's (15) teeth are- in a cross-sectional axial view thereof- convexly shaped (18) and have an axial extent (1) corresponding to the largest possible inclination (2 DEG C) by which the two compensators (6, 7) are adjustable relative to each other. <IMAGE>

Description

SPECIFICATION A device for vertically adjusting the upright axis of a superstructure turnably and inclinably mounted on an understructure This invention relates to a device for vertically adjusting the upright axis of a superstructure,forexample a rescue appliance on a turntable ladderoron atelescopic or on a hinged mast, tu rnably a nd inclinably mounted on an understructure as set out in the opening part of claim 1.

A device of the kind referred to and including two ring-like compensators- one nested in the other and both being disposed between the turntable superstructure and the understructure and being rotatable in the same or in opposite directions- is already known from, for example, DE-OS No. 23 57 470, part icularlyfrom its Figure 9 and the description related thereto. The ring-shaped compensators render it possible to vertically adjust the upright axis of the turntable ladder mounted on a vehicle if, for ex ample,thelatterstopsonaslope.Theadjustmentis effected by rotating the two ring-shaped com pensators relativeto each otherfrom their normal position; their rotation is brought about witch the aid of separate drive units.

Such a drive unitforthe upper one ofthetwocom- pensators is fastened, in known manner, to the chassis and is provided for its rotary drive with a (third) pinion engaging a hollow gearwheel which in turn meshes with an inclined gearwheel ofthe upper compensator. This hollow gearwheel is arranged inside and concentrically with the lower compensator and rotatably supported through a radially outer ant ifriction bearing on an innerflange ofthe lowercom pensator.The aforementioned hollow gearwheel, the gearwheel in engagement therewith and said antifriction bearing cause the manufacturing costs of the known adjusting device to be relatively high and its overall height to be comparatively large. A cumu- lation ofaltogetherfour backlashes of the drive units must be overcome for the purpose of bringing, for example, an upperturntable ladderoftheturnable superstructure into its (rescue-) operating position.

This is the reason why a fully extended turntable lad der can only inaccurately be brought into or located in the desired operating position.

It is an aim of the invention to provide a device for vertically adjusting the upright axis of a super structureturnably and inclinably mounted on an un derstructure of the kind referred to in the opening paragraph, and to ensure that its construction is simple and compact and, more particularly, that its overall height is low.

This aim of the invention is achieved by thefea- turves set out in the characterizing part of claim 1.

The features of claims 2 to 8 are directed to advantageous embodiments ofthe invention.

Thus, an essential feature of the invention is a spe cial rotary drive unit between the understructure and the upper compensator, for which purposeasep- arate (third) pinion is used which is in direct mesh with a (third) annular gear,the said pinionsteeth being in a cross-sectional axial viewthereof-con- vexly shaped and comparatively long in axial direction so that the largest possible inclination between the two compensators can be obtained if they are rotated relative to one another.Thus, the invention replacestheknown hollow gearwheel, the gear wheel in engagementtherewith andthesupporting anti-friction bearing bythethirdannulargearofthe upper compensator, and this third annular gear is in direct mesh with thethird pinion. The result isthat notonlythe number of components is reduced but also that they are less complicated, and that the overall height ofthe device is low in comparison with the known adjusting device. In addition, the number of backlashes in the rotary drive is reduced by one which renders it possible to position the turntable ladder and, respectively, the rescue appliance more accurately.

Thethird pinion is located, in accordance with an advantageous embodiment of the invention, entirely within the lower, conical ring-shaped, compensator, and this notwithstanding the pinion's concavely shaped teeth and their comparatively long length.

Each annular gear is preferably associated with a respective radially outerjournal bearing located at substantiallythe same level. This will result in particularly good support and torque-transmitting conditions inspite of a comparatively slim construction of the individual components.

It is preferableforthethird annulargearto bethe only separate one and to be secured-fast against rotation - by circumferentially disposed countersunk necked-down bolts to the inclined bottom surface on the upper compensator. In contrast, the first and second annular gears are, respectively, an integral part ofthe lower compensator and, respectively, of the upper compensator. Thus, account is being taken of the different transmission forces of the three rotary drive units: the operational load onthefirst and second annular gears including their associated pinions is only small. If at all, it isthethird annular gearwhich issubjecttoaconsiderableloadandthus subject to the risk of wear.It is particularly advantageous,therefore, if the third annulargearis aseparate component which, if need be, can be replaced. The hollow gearwheel including its associated antifriction bearing and the gear of the upper compensator meshing with the former- in the known arrange ment described in the opening partofthisdescrip- tion - are additionally at risk. However, these components are no longer used in a device according to the present invention which, last but not least, contri butts to reducing the manufacturing costs by about 30% and which helpsto reduce the weight and to improve the effìciency of the transmission.

The invention will now be explained in more detail in connection with one embodimentthereof- and compared with a known adjusting device- illustrated intheaccompanying drawings, in which: Figure lisa diagrammatic sketch of an adjusting device serving to make the principle of the invention more easily understood; Figure2 illustrates constructional details ofthe invention; and Figure 3 is a vertical cross-sectional view, similar to that of Figure 2, of a know adjusting device ofthe kind referredto in the opening paragraph.

The diagrammatic sketch of Figure 1 illustrates a device 1 forvertically adjusting the upright axis 2 of a superstructure 4 turnably and inclinably mounted on an understructure 3,the superstructure- in the emb- odiment illustrated - being stationary; alternatively, it may be a vehicle. Theturntable superstructure4 supports an extendableturntable ladder 5. Com- pensators 6 and 7 and the superstructure 4, which are all arranged concentrically within the other and mutually supported by antifriction bearings, can be rotated in relation to each other ifthe understructure 3 as a result of being on a slope is in an inclined position and the upright axis 2 requires, therefore, to be vertically adjusted.The upright axis 2 and hence the turntable ladder 5 are merely rotated if, in the course of carrying out such an adjustment, the outer, ringshaped, compensator 7 is rotated relative to the rotationallyfast understructure 3 and also if the inner, ring-shaped, compensator 6 is rotated relative to the inner superstructure 4 supporting the turntable ladder whereas the inclination of the upright axis 2 is adjusted if the two compensators 6 and 7 are rotated relative to each other. And this adjustment is rendered possible as a result of the antifriction bearing disposed between the two compensators being obliquely mounted.

The outercompensator7 is driven by a rotary drive unit 8 fastened to the understructure,the inner compensator 6 by a lower rotary drive unit 14 also fastened to the understructure and the turnable superstructure 4 is driven, as far as the inner compensator 6 is concerned, by a rotary drive unit 11 fastened to the superstructure.

The specific embodiment of the adjusting device 1 according to the invention illustrated in Figure 2 comprisestheunderstructure3,which is ring shaped, and theturnably and inclinably mounted, and also ring-shaped, superstructure 4,the configuration of both these structures being substantiallythe same. The lower compensator7 shaped like a conical ring is concentrically mounted within the understructure 3 and supported ring is concentrically mounted within the understructure 3 and supported therein byan antifriction bearing 19. The turnable superstructure 4 is likewise supported by an antifriction bearing 20 in the upper compensator 6 which is also shaped like a conical ring.The last mentioned compensator, in turn, is supported through an obliquely arranged antifriction bearing 21 by the lower conical ring-shaped compensator 7.

The lowercompensator7 is provided at the axial level ofthe bearing 19with aninnerintegrally formed-first- annular gear 10 meshing with a first pinion 9 ofthe drive unit 8 fastened to the under structure.As a result, the lower compensator 7 is rotatable in relation to the understructure 3.

The upper compensator 6 is provided, like the lower compensator7, at the level ofthe associated bearing 20with an innerintegrallyformed- secondannular gear 13 meshing with a second pinion 12 of the- second- drive unit 11 fastened to the superstructure 4which, as a result, is rotatable about the upright axis 2 in relation to the uper compensator 6.

The upper compensator 6 is arranged to be driven bythe-third- drive unit 14 which is fastened to the understructure and the drive-transmitting - third - pinion 15 ofwhich is located entirely within the lower compensator 7. This third pinion, and this is an essential feature of the invention, is in direct mesh with athird annulargear 17fastened bycircumferentially evenly distributed counter-sunk necked-down bolts 23 to the inclined bottom surface 16 ofthe upper compensator 6. Thethird annulargeartoo is located entirely within the lower compensator 7 and rotatably supported thereon through the obliquely arranged antifriction bearing 21.The latter is also located substantially at the axial level of the teeth ofthethird annular gear 17.

Afurther essential feature ofthe invention illustrated in Figure 2 is thatthe third pinion's 15 teeth are- in a cross-sectional axial viewthereof- of convex shape 18 and have a marked axial extent 1 corresponding to the largest possible inclination 20e (by which the relatively rotatable compensators 6 and 7 are adjustable.

The driving shafts ofthe rotary drive units 8 and 14 run parallel with each other, as shown in Figure 2, and both extend parallel with the axis of rotation of the lower compensator 7. The driving shaft ofthe upper drive unit 11 which is fastened to the superstructure 4 runs parallel with the upright axis 2 thereof.

Compared with the invention as illustrated in Figure 2, a chassis-mounted rotary drive unit 14 of the known adjusting device is provided with are lativelysmall pinion 15 meshing with a hollow gear wheel 26 which is rotatably supported through an additional antifriction bearing 22 by the lowercompensator7. The hollow gearwheel'steeth,which are lengthened, also mesh with an obliquely arranged inner gearwheel 27 secured by bolts 28 to the upper compensator 6. The latter has an annular recess 29 which affords ample free space forthe operation of the teeth ofthe gearwheel 27 and ofthe upper axial extension of the hollow gearwheel 26.

It is evident from Figure 3 illustrating the known adjusting device that its upper compensator's 6 rotary drive unit comprises more component parts than the drive unit according to the invention, that is to say the additional antifriction bearing 22, the hollow gearwheel 26 and the gear wheel 27. Moreover, there is in the rotary drive unit ofthe upper compensator an additional backlash between the gearwheel 27 and the hollow gear wheel 26. This additional backlash impairsthe accuracy of positioning theturntable ladder 5 mounted on the superstructure 4. A further comparison makes clearthat the known device, due to the recess 29 in the upper compensator 6 and to the comparatively small pitch circle diameter of the gear wheel 27, is suitable only for transmitting relatively low torques, the reason being that in operation of the hollow gearwheel 26, the gearwheel 27 and the upper compensator 6 of the known adjusting device are subjectto high stresses and thus susceptible to premature wear.A final comparison makes clearthatthe invention, according to an advantageous em bodiment thereof, usesforthecompensators 6 and 7 innerannular gearswhich are formed integ ral Iy therewith - in con- trastto the known state ofthe art which uses sep- arate component parts. The construction ofthe two last mentioned drives can be relatively weak but that ofthethird rotary drive unit 14 must be a sturdy one.

All new features referred to in the description andl or illustrated in the drawings are materially intrinsic ones ofthe invention, beitbythemselvesorin rational combination - even if they have not been expressly claimed in the claims.

Claims (8)

1. Adevice (1 )forvertically adjusting the upright axis (2) of a superstructure (4)for example a rescue appliance on a turnable ladder (5) or on a telescopic oron a hinged mast-turnablyand inclinablymounted on an understructure (3), the device comprising two superposed compensators (6,7) which are shaped like conical rings, are disposed between the turnable superstructure (4) and the understructure (3) and which are rotatable in the same or in opposite directions, in which a first rotary drive unit (8) fast ened to the understructure driving meshes via a first pinion (9) with a first annulargear (10) ofthe lower rotatable compensator (7), in which a second rotary drive unit (11) fastened to the superstructure drivingly meshes via a second pinion (12) with a second annular gear (13) ofthe upper rotatable com pensator (6), and in which a third rotary drive unit (14) fastened to the understructure is driving con nected via a third pinion (15) to the uppercompensa- tor (6), characterized in that said driving connection is completed by a third annular gear (17) secured fast against rotation - to the inclined bottom surface (16) ofthe uppercompensator(6),thatthethird an nulargearis in mesh with the third pinion (15), and in that the third pinion's (15) teeth are- in across- sectional axial view thereof- convexly shaped (18) and have an axial extent (1) corresponding to the lar gest possible inclination (2 ) by which thetwo com- pensators (6,7) are adjustable relative to each other.

2. A device according to claim 1 or claim 2, char acterized in that the third pinion (15) is located within the lower compensator.

3. A device according to claim 1 or claim 2, char acterised inthatthethird pinion (15) andthethird annulargear(17) arestraight4oothed.

4. A device according to any of the claims 1 to 3, characterized in that each annular gear 13,17) is associated with a respective radially outerjournai bearing (19,20,21) located atsubstantiallythe same level.

5. A device according to any of the claims 1 to 4, characterized in that the first and second annular gears (10,13) are, respectively, an integral partofthe lower compensator (7) and, respectively of the upper compensator (6).

6. A device according to any of the claims 1 to 5, characterized in that the third annular gear (17) isfastened by circumferentially disposed counter-sunt necked-down bolts (23) to the inclined bottom sur face (16) of the uppercompensator.

7. A device according to any of the claims 1 to 6, characterized inthatthethird pinion (15) and the third annulargear(17) are each made of a highly wear-resistant material.

8. Adevice according to anyoftheclaims4to7, characterized in thatthejournal bearings (19,20,21) are antifriction thrust bearings.