FR2708584A1 - Device for selectively controlling the simultaneous or synchronised telescopic movement of two constituent elements of a telescopic jib for a crane - Google Patents

Abstract

- Crane with telescopic jib - The device is characterised in that the locking means (30) comprises: on the reference element (10) . a drive unit (31) . and a mobile lock (32) controlled by the said unit and including a head (46) for locking onto the endless chain (20) . a shoe (50) defining a lug capable of accommodating the locking head of the bolt and an installation for remotely controlling the drive unit. - Application to self-propelled mobile cranes.

Description

SELECTIVE TRAVEL CONTROL DEVICE
SIMULTANEOUS OR TELESCOPIC SYNCHRONIZED OF TWO COMPONENTS OF A TELESCOPIC FLANE OF CRANE
The present invention relates to the technical field of telescopic jib cranes, whether installed in a fixed position or carried by self-propelled mobile structures or not.

 In the above technical field, the telescopic jibs are, most generally, mounted on a turret orientable in azimuth relative to a load-bearing structure and on which turret is articulated in elevation an arrow generally constituted by at least three separate telescopic elements . The first element is said to be basic, the second intermediate element and the third extreme. These three elements are intended to allow the length of the boom to be adjusted so as to vary the distance between the elevation adjustment axis and a boom head pulley on which a cable wound or unwound from is guided and deflected. '' a basic winch to vary the vertical distance of a load suspended from the part of the cable extending beyond the jib head pulley.

 As a general rule, the telescopic elements are extended or retracted by means of at least one hydraulic cylinder which can be supplemented, for the extreme segment, by a selective drive device.

 The maximum length of such a boom is determined by the extension of the various telescopic elements which, in a certain number of applications, do not have to be developed all in a synchronized telescopic manner.

 This is the reason why it is generally planned to use a telescopic jack for development between the base element and the intermediate element only. A loop chain system is then interposed between the intermediate element and the extreme element carrying the head pulley, so as to make possible, by a locking system, either the simultaneous exit without relative extension of the intermediate element and of the end element, or even the proportional synchronized telescopic outlet of the end element relative to the intermediate element.

 Such a principle can be retained, and is frequently it, in the cases of construction involving more than three elements for the constitution of the arrow.

Indeed, the problem is exactly of the same order when it is necessary to reason for an extreme element which can be a segment number 4 or number 5 compared to the intermediate element which is attached to it and which carries it.

 In all known cases of the prior art, the selective control device, provided between the end element and the intermediate element, is constituted by a locking-unlocking mechanism by means of an axis, a pin or a spindle that must be mounted or removed manually, requiring the operator to physically move it to the affected components.

 Thus, whenever it is necessary to pass from one functional state to another, that is to say to provide for the simultaneous exit of the extreme element and of its intermediate element or on the contrary the synchronized telescopic exit, it it is necessary to interrupt the process of using the crane, so as to place the boom in a spatial situation compatible with physical access to act manually on the locking system and / or unlocking.

 It is understandable that such a subjection is not likely to bring together the safety factors imposed in this type of activity and requires a significant downtime in the process of using the crane to place it in a neutral position or stable position allowing intervention on the unlocking system.

 The object of the invention is to remedy the above drawbacks by proposing a device for selective remote control of the simultaneous or telescopic synchronized movement of two components of a telescopic boom of a crane.

 The object of the invention is to provide a device adaptable to any telescopic crane boom regardless of the number of elementary telescopic segments it comprises and whether it is of the fixed or mobile station type.

To achieve the above objective, the control device according to the invention is characterized in that the locking means comprises:
- on the reference element
an engine block
and a movable lock controlled by said block and comprising
a locking head
- on the loop chain:
a shoe defining a snap capable of receiving the head of
lock lock.

 - and a remote control unit for the engine block.

 The invention also relates to a telescopic jib crane, of the fixed or mobile station type, equipped with a control device according to the invention.

 Various other characteristics emerge from the description given below with reference to the appended drawings which show, by way of nonlimiting example, an embodiment of the subject of the invention.

 Fig. 1 is a schematic view illustrating the field of the invention.

 Fig. 2 is a schematic view showing the constituent elements according to the invention.

 Fig. 3 is a perspective showing the installation of the device on a crane boom.

 Fig. 4 is an exploded perspective view illustrating two constituent elements of the subject of the invention.

 Fig. 5 is a diagram of a supply circuit for one of the motor elements of the device.

 Fig. 6 is an elevation similar to FIG. 2 but illustrating an example of operation.

 Fig. 7 is an exploded perspective similar to FIG. 4 but showing one of the constituent elements of the invention in another characteristic position.

 Fig. 8 is a schematic view similar to FIG. 6 but illustrating a different functional phase.

 Fig. 1 shows an example of application of the object of the invention to a crane of the mobile and self-propelled type. Such an example is only given by way of illustration because the object of the invention could be implemented just as well on a crane installed at a fixed station.

 The crane, according to fig. 1, comprises a platform or a chassis 1 carried by rolling bodies 2 constituted, for example, by several power steering trains. The platform or the chassis 1 comprises a driving and control cabin 3 housing or not housing one or more engine and / or propulsion units.

Lateral stabilizers 4 are provided on the chassis 1 substantially in line with the front and rear parts to provide a stable attitude when the crane is put into service.

 The platform 1 also comprises a turret 5 which is orientable in azimuth on an axis x-x '. The turret 5 carries by an axis 6 an arrow 7 which is orientable in site by means of a jack 8. Traditionally, the arrow 7 is constituted by telescopic elements, for example, four in number, called base for element 9, intermediates for elements 10 and 11 and end for element 12 which is provided with an arrow head pulley 13. The arrow 7 is completed by at least one cable or the like 14 wound or unwound from a winch 15 and passing over the pulley 13 beyond which it is designed to suspend a load 16.

 In a conventional manner, the arrow 7, formed from four telescopic elements, is provided internally with a system 17 of telescopic cylinder (fig. 2), designed to control the extension and retraction telescopic synchronized or not of the elements 10 and 11 with respect to element 9. Such a jack system, pertaining to the prior art, is not described further in the following because, strictly speaking, it does not fall within the object of the invention. The same applies to all of the additional control, relative adjustment or sliding members which must be considered to be within the reach of those skilled in the art.

 The turret 5 also supports a control cabin 18 reserved for maneuvering mainly means for actuating the boom, such as the jack 8, the winch 15, the jack 17 and the engine for orienting the turret in azimuth.

 The selective control device according to the invention is designed to cause the synchronized simultaneous or telescopic movement of the element 12 and of the element 11 relative to a reference element which is in this case the element 10. The device illustrated schematically in FIG. 2, involves, between the end segment 12 and the intermediate segment 11 which carries it and the guide, a closed loop link 20 which is established around idler rollers 21 and 22, respectively carried by the rear and front parts of the intermediate element 11.

The roller 22 is adapted to the part of the element 11 which is located in all the configurations of the boom outside of the element 10. The link 20 is generally constituted by two types of chains, one 20a so-called telescoping out and the other 20k called booster. The chain 20a responsible for the relative synchronized telescopic output between the elements 12 and 11, has mechanical resistance characteristics far superior to those of the chain 20b. The two chains 20a and 20b constitute the loop 20 which, preferably but not exclusively, also passes over inflection and guide rollers 23 and 24 which are mounted on the top of the element such as 10 carrying the element 11 .

 The loop 20 is, moreover, made integral with the rear end portion of the end element 12 by a fixing 25 which may consist of any suitable means capable of establishing a fixed but nevertheless removable connection between the loop 20 and the end element 12.

 The selective control device according to the invention comprises, as is apparent from FIGS. 3 and 4, a means 30 known as locking between the loop 20 and the base element which can be element 9, in the case of a three-element arrow, or element 10, in the case of an arrow with four elements of the type shown.

 The locking means 30 comprises a motor unit 31 and a movable lock 32 which can be constituted in the form of a unitary assembly, in the case of a three-element boom, the basic one of which then carries said unitary assembly. In the case of a four-element boom, it can be provided, as illustrated in the drawings, to constitute the motor 31 and the latch 32 in the form of two independent elements respectively adapted on the element 9 and on the element 10. Such an adaptation may be preferred to arrange the motor 31 on a fixed element and thus facilitate the establishment of the energy supply link.

Different possibilities of structural organizations can be retained, as well as different choices of drive components and locks.

 In the example illustrated, the lock 32 is of the rotary type and the engine block 31 of the pneumatic type. It must, however, be considered that an electric or hydraulic engine block 31 could also be envisaged.

 In the construction example illustrated by FIGS. 4 and 5, the engine block 31 comprises a jack 33, of the double-acting type and with a straight stroke, the rod 34 of which, for example common to two pistons, is provided with a rack capable of driving a shaft in rotation motor 35 able to cooperate with latch 32.

Conventionally, such an alternative rectilinear stroke motor comprises two limit switches making it possible to supply signals corresponding to one and the other of the two extreme stable positions capable of being occupied.

 Fig. 5 shows an example of pneumatic supply to the jack 33 by means of a pneumatic distributor 37 which is controlled by two solenoid valves 38 and 39 connected in bypass on a circuit 40 for supplying pneumatic fluid under pressure.

 The engine block 31 and the latch 32 are associated in the example illustrated by a separable control link 41 comprising a yoke or the like 42 presented by the shaft 35 and a tenon 43 formed by the rear part of the latch 32.

 The lock 32, which is of the rotary type, is mounted in a bearing 44 whose axis is parallel to the direction of travel of the loop 20, in particular as regards its upper strand. The latch 32 therefore includes a body 45 able to cooperate with the bearing 44 and a head 46 which forms at least and preferably two diametrically opposite shoulders 47. The rotating body 45 of the lock 32 is, moreover, equipped with indexing means 45a able to cooperate with a blocking member 48 which is automatically controlled as soon as the telescoping function of the elements of the boom intervenes. The means 45a can consist of two notches presented by a flange of the body 45 and corresponding to the two positions of the lock in a locking and unlocking state as described in the following. The blocking member 48 can be completed by a position sensor.

 The locking means 30 moreover comprises a shoe 50 which is adapted to the loop 20. Preferably but not exclusively, the shoe 50 is provided to ensure the connection between the chains 20a and 20k in the part of the latter between the pulley 22 and the pulley 24, in a state of maximum retraction of the telescopic elements. The shoe 50 is constituted by a massive piece comprising, in the front central end part, a comb 51 for connection with the telescoping chain 20a and in the rear part two branches 52 respectively provided with a comb 53 for the connection with a component strand of the reminder chain 20k.

 The massive piece defines by the branches 52 a sort of snap defining a corridor 55 (fig. 7) which opens into a housing 56 at the base of which are formed, in the border area with the corridor 55, two stops 57 reserved for the cooperation with the shoulders 47 of the head 46.

 The device described above operates in the following manner.

 On the basis of fig. 2, the various constituent elements of the arrow 7 are in the mutual retraction position obtained by the corresponding suitable control of the telescopic jack 17.

 In this state and on the basis of fig. 4, the head 46 of the latch 32 is disposed in the housing 56 so that the shoulders 47 cooperate with the stops 57. In this state, the body 45 is immobilized in the position indexed by the member 48 and the information is transmitted to the cabin 18 at least by the corresponding sensor of the engine 33.

 The locking device 30 thus establishes a positive connection between the loop 20 and the reference element which is either the base element 9 or the intermediate element 10 depending on whether it is a three or four arrow elements.

In such a situation, if the telescopic jack 17 is supplied to control the extension of the boom 7, the elements 10 and 11 are moved relatively in telescopic extension with the effect of displacement, in the direction of the arrow fi (fig. 2 ), of the pulley 22 relative to the element 10. Since the loop 20 is secured to the element 10 by the latch 32, the movement in the direction of the arrow fi of the pulley 22 causes the winding of the chain 20a in the direction of arrow fz, which causes, due to the connection 25, the corresponding movement of the end element 12 in the same direction. Such a displacement causes the chain 20k to wind around the idler pulley or the chain wheel 21, as the corresponding output from the intermediate element 11 progresses. (Fig. 6)
Thus, when the locking device or means 30 links the loop 20 with the element 10 or 9, as the case may be, the supply of the telescopic jack 17 causes the synchronized telescopic output of the extreme element 12 intervening at the same time as that other intermediate elements 11 and 10 relative to the base element 9 in the case of a four-element boom, which is produced by the supply of the jack 17. It must, of course, also be considered the case where the jack 17 or its technical equivalent is provided to allow a supply in order to cause a sequential operation of the elements 10 and 11 by independent control.

 A reverse operation to that which has just been described is established when the telescopic jack 17 is supplied in the opposite direction to cause the re-entry of the various elements corresponding to the retraction stroke of the boom 7.

 it can be considered that, in the state according to fig. 2, the locking means occupies, on the contrary, the position according to FIG. 7 in a stable state indexed by the member 48. Such a position is obtained by controlling the engine block 31 to rotate the shaft 42 so as to place the head 46 of the lock 32, not in the plane of the solid part 50 constituting the snap, but perpendicular to the plane of the latter. In such a state, the head 46 is then free to move relative to the interior of the housing 56 and of the corridor 55.

 In such a state, the supply of the telescopic jack 17 produces, as said previously, the telescopic movement of the intermediate element 11 and, consequently, the corresponding movement in the direction of the arrow fi of the pulley 22 which, this time , carries with it the loop 20, since the chain 20b is no longer linked to the element 10 or 9 by means of the locking means 30 (fig. 8). Indeed, in such a case, the shoe 50 is driven in displacement at the same time as the element 11, while the latch 32 remains immobilized on the carrier element 10 or 9 as the case may be.

In such a situation, the loop travels relative to the return rollers 23 and 24 without relative movement of the chains between the rollers 21 and 22. Thus, the displacement at the outlet or extension of the intermediate element 11 occurs without causing synchronized telescopic movement concomitant of the extreme element 12 which remains in the relative retracted position which it occupies with respect to the intermediate element 11. (fig. 8)
When feeding the telescopic jack 17 in the opposite direction, the retraction of the intermediate element 11 brings the shoe 50 in relative presentation relative to the head 46 of the lock 32, which engages relatively in the passage 55 to be brought inside the housing 46. Such a state is noted for example by a bar or other member 60 carried by the solid part 50 and capable of influencing a sensor, not shown, controlling the supply of the motor 31 to rotate the head 46 in engagement behind the stops 57.

 It must, of course, be considered that technical means equivalent to those described above can be provided with regard, in particular, to the members of the locking means 30. Thus, the catch provided in the context of a twist lock can define a simple closed housing in which it can be provided to ensure the engagement of the head of a lock which would then be tiltable.

 Figs. 3 and 4 show that the solid part 50 is advantageously provided with lateral pads 70 which provide a guiding and alignment function to cooperate in particular with the top of the element 10 at the end of the retraction stroke and thus favor the relative engagement between the head 46 and the passage 55 and the subsequent cooperation between the shoulders 47 and the stops 57.

 The invention is not limited to the example described and shown since various modifications can be made thereto without departing from its scope.

Claims (11)

CLAIMS:  1 - Device for selective remote control of the simultaneous or telescopic synchronized movement of two elements (12 and 11) constituting a telescopic boom (7) of a crane and called respectively extreme and intermediate with respect to at least a third element ( 10) said reference, arrow comprising a system (17) of telescopic jack, a chain or the like (20) established in a closed loop on idler rollers (21, 22) carried by the intermediate element, and fixed on the end element and means (30) for locking the chain with respect to the reference element.  characterized in that the locking means (30) comprises:  - on the reference element (10)  an engine block (31)  and a movable lock (32) controlled by said block and  having a locking head (46)  - on the loop chain (20)  a shoe (50) defining a snap suitable for receiving the head of  lock lock  - and a remote control unit for the engine block.  2 - Device according to claim 1, characterized in that the latch (32) is of the rotating type.  3 - Device according to claim 1, characterized in that the lock is of the tilting type.  4 - Device according to claim 1, 2 or 3, characterized in that the lock comprises a head (46) provided with at least one shoulder (47) able to cooperate with a complementary stop (57) presented by the catch.  5 - Device according to one of claims 1 to 4, characterized in that the lock is mounted rotating in a bearing whose axis is parallel to the running direction of the chain.  6 - Device according to one of claims 1 to 5, characterized in that the lock is of the type with two stable positions of engagement and release respectively with respect to the shoe catch (50) and comprises means (45a) indexing capable of cooperating with a locking member (48) in one and the other of these positions.  7 - Device according to claim 1, characterized in that the shoe (50) is constituted by a solid piece linked to the ends of the looped chain (20).  8 - Device according to claim 7, characterized in that the solid part comprises a front central part (51) linked to a chain (20au telescoping output and two rear branches (52) linked to two chains (20b) of return.  9 - Device according to claim 1, 7 or 8 characterized in that the shoe (50) defines, between the two rear branches, the snap which defines a housing (56) for engaging the locking head (46).  10 - Device according to claim 9, characterized in that the housing (56) is of the open type and communicates with a passage (55) of entry-exit of the head, such a corridor delimiting with the housing two stops (57) of engagement of the two shoulders (47) of the head of the lock.  i1 - Device according to claim 1 or 9, characterized in that the shoe is provided with pads (70) for guidance and alignment promoting, at the end of the retraction stroke, cooperation with the head of the lock.  12 - Crane with telescopic boom comprising a device according to one of claims 1 to 11.