US3533358A - Device for compensating automatically for variations in the tension on and length of cables in appliances for transferring loads between two moving objects by cables - Google Patents

Description

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[56] References Cited UNITEDSTATES PATENTS lnve ntor Pierre Lel enberger,

Nantes, France App]. No. 733,048 1 Filed May 29, 1968 Patented Oct. 13, 1970 1 Assign Societe des Forges et Ateliers du Creusot Paris, France United States Patent end .mwm V CW flan b n 0 ldc m m m m f-In m m W g U H m .m m m okd u m n n mim m m o mm X .n Sti H "0 C m: was mm c mmm.. m 0d nv w u n m m u r H u .ilil liilliulllli [ORE-i rrm e k lfin da h HMBWHM 0g... 3 n i MDPSMB mm DK v m 990 58 n 006666 w 999999 a... meg /HHHHH .nm n 336221 m w W mm 8 0890 E C 5004 78 9 A l. J U Rfi m 56 24 am T .we 11 17.6 m Vl- 9 ,2 n H B r m llllilr 2333 PA Avmww ml U 4 c D l 3 47 2 l 1 mm c i B 6 6 B L .J 3 m l n" 0 n 7 n m a a 2 (v i 3 1 9 L I e l u i 8 m 9, 9 m 1 Q l M 7 m u 0 J 1 Dec. 7, 1967 France L m m Priority AUTOMATICALLY FOR VARIATIONS IN THE TENSION ON AND LENGTH OF CABLES IN APPLIANCES FOR TRANSFERRING LOADS BETWEEN TWO MOVTNG OBJECTS BY CABLES 9 Claims, 20 Drawing Figs.

[54] DEVICE FOR COMPENSATING Patented Oct. 13, 1970 3,533,358

Sheet of 8 Patented Oct. 13, 1970 Sheet 2 018 Patmted Oct. 13, 1970 Sheet Patented Oct. 13, 1970 I 3,533,358

Sheet 5 of 8 Patented Oct. 13, 1970 Sheet Patented Oct. 13, 1970 I 3,533,358

Sheet of a FIG. 19-

DEVICE FOR COMPENSATING AUTOMATICALLY FOR VARIATIONS IN'THE TENSION ON AND LENGTIIOF CABLES IN APPLIANCES FOR TRANSFERRING LOADS BETWEEN TWO MOVING OBJECTS BY CABLES v in the tension'and length of cables due essentially to small divergences in speed and from parallel direction of two ships in motion, and to any rolling and pitching movements to which the shipsmay be subjected.

These cable-transfer appliances generally comprise a carrier cable, stretched between two ships, and on which there runs a carriage supporting the load, and a cable governing the outward and return movements of the carriage along the carrier cable.

It will be understood that it is desirable, in spite of relative movements between the two ships, to maintain substantially constant tension on the one hand on the carrier cable in order to prevent irregular movements of the load in the vertical plane, and on the other hand on the carriage-governor cables in order to be able to keep positive control of the operations of despatching the load from, and bringing it up to, both ships.

Constant tension is automatically maintained on the carrier cable and on the carriage-governor cables in the compensating device to which the present invention relates.

According to the invention, the automatic compensating device comprises winders disposed on the moving object carrying the cable-winches and each assigned to compensating for variations in the length of one of the cables, the winders being interconnected and subjected to the action of a common return force of constant value in the direction of applying tension to the cables.

The invention will be described hereinafter in greater detail with reference to the various forms of embodiment which are illustrated in more or less diagrammatic fashion in'the appended drawing.

FIG. 1 is a diagram showing the principle of an appliance for carrying out transfers between two moving objects by cables;

FIGS. 2, 3 and 4 are diagrammatic views showing a device for carrying out compensation by running the cables through pulley-blocks, as applied respectively to each of the two opposite directions of transfer and to the general case of transfers in both directions;

FIGS. 5 and 6 are diagrammatic views showing two variants in the application of the constant tensioning force to the cables in a device for carrying out compensation by running the cables through pulley-blocks;

FIGS. 7, 8 and 9 are diagrammatic views showing a device for carrying out compensation by mechanically interconnecting the winches, as applied respectively to each of the two opposite directions of transfer and to the general case of transfers in both directions;

FIGS. 10 and 11 are principle diagrams similar to those of FIG. I, and showing the variations in sag and tension on the cables in the course of a transfer;

FIG. 12 is an overall diagrammatic view, showing a method of interconnecting the winches of the operating cables, and auxiliary tensioners for taking up variations in the length of these cables as a function of the variations in sag of the three cables,

FIGS. 13 and I4 are partial views extracted from FIG. 12, and showing two variants in the interconnection of the winches of the operating cables;

FIG. 15 is a principle diagram similar to that of FIG. I;

FIG. 16 is a diagrammatic view showing a repeater for the positions and movements of-the load;

FIG. 17 is a diagrammatic view showing how the positions and movements of the load are posted in the repeater illustrated in FIG. 16;

FIG. 18 is an overall diagrammatic view showing a variant of embodiment of the interconnection of the winches by dif- FIGS. 19 and 20 are a principle diagram and an overall diagrammatic view respectively of a variant of embodiment according to which the carrier cable takes the form of one of the operating cables.

The principle diagram in FIG. 1 shows an appliance for carrying out transfers between two arrival stations A and B fitted up respectively on two ships spaced from one another by a distance E which may be variable, the said ships being liable to oscillate about two roll axes a and b, themselves moving in space.

A carrier cable C, constitutes the running track of a carriage 1 from which a load P is suspended. The cable C which is secured at 2 to the station B, is linked to a winder D, in the station A. The carriage I is attached at 3 to two opposed operating cables C and C,, which are respectively linked to two winders D and D in the station A, the cable C, passing over two deflector pulleys 4 in the station B.

The movements and positions of the carriage l, and consequently of the load P, depend at each instant on the relative movements between the stations A and B and on the tension on the cables C,, C C determined by the winders D,, D D;,.

It is clear that the tension on the carrier cable C, must remain substantially constant in order to avoid irregular movements of the load P in the vertical plane; likewise, the tension on the operating cables C C must make it possible on the one hand to control the arrival and departure speeds of the carriage at both stations, and on the other hand to keep the carriage in its arrival positions with respect to both stations.

Compensation for variations in the length of the three cables and control of the tension thereon are carried out automatically in a first form of embodiment according to the invention by means of three cable-winders comprising pulleyblocks, as illustrated in FIGS. 2, 3 and 4.

In FIG. 2, there is a limitation to the case of transferring the load with control over the arrival of the load at B.

In the station A, the three cables C C, and C,,, which pass over deflector pulleys 5 and tensioning pulleys6 mounted on a yoke 7 from which a common weight Mis suspended, are attached to three winches T,, T and T respectively.

For the sake of clarity in the drawing, the two groups of pulleys 5 and 6 are illustrated as having separate spindles, but it goes without saying that in each group the pulleys may be mounted on a common spindle.

The three pulley-blocks give a constant sum of the tensions on the three cables, the sum of the tensions being equal to M/2. Pulley-blocks with a plurality of runs of cable may be provided, for example for the operating cables C and C,,, in order to obtain a constant greater tension on the carrier cable C,, the sum of the tensions remaining constant.

The speed at which the carriage I arrives at the station B is easily controllable. If it is assumed that the winches T,, T and T are stationary, the carriage 1 follows the movements of the station B, since the variation in the length of the cables is compensated for by thepulley-blocks in the station A. Under these conditions, if the winch T is caused to wind at a speed equal to the unwinding speed of the winch T,, for example by means of a mechanical coupling between these two winches, this speed which is easily adjustable, constitutesthe speed of arrival at the post B, whatever the direction and amplitude of relative movements between the two stations.

in FIG. 3, there is a limitation to the case .of transferring the load with control over the arrival of the load at A.

In this case, the cable C is directly attached to a winch U,,; the cable C, is attached to a winch U, after passing over a pulley-block pulley 6, while the cable C,, which is attached to a winch U,,, undergoes double blocking by passing over its pulley8, linked to the weight M, and over a fixed pulley 9, the sum of the tensions on the three cables being substantially constant.

The speed at which the carriage l arrives at the'station A is likewise ,easily controllable. The three winches U,, U,, U,,

being stationary, the carriage 1 follows the movements of the station A; for any variation in the distance between the two stations the distances traversed by the cable C, will be twice as great as those traversed by the cable C the length of the cable C being constant. Consequently, if the winch U is caused to wind at a speed equal to the unwinding speed of the winch U the speed of arrival at the station A will be controlled, and will be that at which the cable C, is wound.

In the foregoing, only the control of arrivals at the stations A and B is described; it goes without saying that the load is controlled in its departure from both stations by the same means, simply by inverting the directions of winding and unwinding on the winches T T (FIG. 2) or U U (FIG. 1).

FIG. 4 applies to the more general case of bringing in and launching the carriage on its own or loaded, at both of the two stations.

As FIG. 4 shows, the station A comprises a pulley-block for the cables C,, C C according to FIG. 2, made up of pulleys 6 and a weight M,, and a pulley-block for the cables C, and C according to FIG. 3, made up of the pulleys 8, 9 and a weight M the cables C, and C being guided between the two pulleyblocks by the deflector pulleys l and 11.

The two weights M, and M are provided with brakes for locking to the respective guides m and m braking being carried out, for example, by means of remote control by electromagnets, not illustrated.

Transfer of the load from the station A to the station B will proceed in the following manner:

At the start of launching the weight M, will be locked by its brake, the weight M, being free. Unwinding the cable C, by the winch U and winding up the cable C by the winch U, will launch the load at the unwinding speed of the cable C In order to bring the load up to the station B, the weight M, will be released and the weight M, will be locked before the load approaches the station B. Controlling the speeds of the winches U, and U determines the speed at which the load arrives at the station B.

Transfer of the load from the station B to the station A will proceed in the same manner, the weight M, alone remaining released at the time of launching; before arrival at the station A, the weight M, will be locked and the weight M released.

The operations of locking and releasing the two weights may be combined so as to take place in fully automatic fashion.

The pulley-blocks for the three cables in the station A may be of the type comprising multiple runs of cable, so as to limit the movements of the weightsM, and M and to make the sums of the tensions on the cables different while these weights are of the same value.

Likewise, instead of using weights such as M in order to determine the tensions on the cables, recourse may be had to elastic return forces, exerted for example by a spring or by a pneumatic or oleopneumatic device; the return members M may be inserted either between the pulley-block yokes 7 and a fixed point 13 (FIG. and work in tension, or between the pulley-block yokes 7 and a fixed yoke 7a supporting the fixed pulley-block pulleys 6a (FIG. 6), and work in compression.

[n a second form of embodiment according to the invention, compensation for variations in the lengths of and tension on the cables is provided by means of three winders comprising mechanical differentials, as illustrated in FIGS. 7, 8 and 9.

In FIG. 7, there is a limitation to controlling the load in its arrival and launching at the station B (FIG. 1).

In the station A, the cable C, is attached to a winch t, driven by a reversible constant-torque motor F,; the cables C and C are attached to two winches t and 2;, respectively, each linked to one of the planetary gears q, of a differential Q whereof the other planetary gear q is linked by a pinion q, to a pinion q, fast with the shaft of the winch t,.

The cages q of the two differentials are linked respectively by gears e and e, to the motors F and F The ratios between the diameter of the winch t1 and the diameters of the winches t r, on the one hand, and between the diameter of the pinion q and the pinions q, on the other hand, are made such that when the motors F and F are stationary the winding and unwinding speeds of the cables C,, C, and C are equal. 1

The relative speed of the load upon arriving at the station B is easily controllable. The motors F and F being stationary, they lock the cages q of both differentials Q. The three cables are allowed to wind and unwind as a result of relative movements between the two stations, and the load follows the movements of the station B. The motors F and F being linked to one another by a mechanical or other coupling, not illustrated, the cable C is caused to unwind at a speed equal to the winding speed of the cable C this speed being the desired speed of arrival or launching at the station B.

In FIG. 8, there is a limitation to controlling arrival and launching at the station A (FIG. 1).

The cable C is attached to the winch u which is directly driven via the gears e by the motor F The cable C, is attached to the winch 14 which is linked via the differential Q to the motor F by the gears 6 and to the pinion (1;, in mesh with the pinion q fast with the shaft of the winch u,. The ratio between the pinions q, and q, is chosen sothat when the motors F and F, are stationary the winding and unwinding speed of the cable C will be twice as great as the winding and unwinding speed of the cable C,. The load follows the movements of the station A; the speed of winding the cable C and unwinding the cable C by the two motors F and F coupled to one another will be the speed of arrival or launching at the station A.

FIG. 9 applies to the general case of arrivals and launchings at both stations by means of a particular combination of the devices comprising winches and differentials according to FIGS. 7 and 8.

The winch u, for winding the cable C, is linked by the pinion q,, and the two pinions q to the differential Q of the winch a and to the differential Q of the winch u On the shafts of the planetary gears q of the differentials Q and Q there are clutches p and p respectively, enabling these planetary gears to be disconnected from the corresponding pinions q;,.

The shaft of the planetary gear q of the differential O is furthermore equipped with a locking brake f while the shaft of the planetary gear q of the differential Q carries a pinion q in mesh with a pinion q, keyed to a shaft q which is linked by way of a clutch p, to the shaft of the winch 11. The ratio between the pinions g and q is half the ratio between the pinions q and q,,.

For arrivals and launchings at the station B, the brake f is released, the clutches p and p, are engaged, and the clutch p is disengaged. The operation is then that described for the case of FIG; 7.

For arrivals and launchings at the station A, the brake f is locked, the clutches p p are disengaged, and the clutch p is engaged. The operation is then that described for the case of FIG. 8.

The use of winders comprising mechanical differentials according to FIG. 7, 8 and 9 has the advantage of allowing for continuous variations, of any desired value, in the distance between the two moving objects while an operation of transferring a load from one moving object to the other is in progress.

The devices for compensating for variations in the lengths of cables which have just been described, comprising pulleyblocks for the cables or comprising differentials, may be completed in accordance with the invention by auxiliary members for compensating for variations in the lengths of and tensions on the operating cables due to the variable sag of the carrier cable under the action of the load being transferred.

FIGS. 10 and 11 are views extracted from FIG. 1, showing respectively the load P in the vicinity of the station A and in the middle of the span between A and B.

It will be understood that the loop closed by the operating cables C and C will be larger in the case of FIG. 11 than in the case of FIG. 10. When the load P is displaced from A towards the middle of the span, the cable C retards the descent, and the tension on the cable C must be sufficient to limit the free sag of this cable. Likewise, when the load P goes from the middle of the span towards the station B, the cable C becomes the driving cable, and the tension on the cable C must be sufficient to limit its sag. The tensions on the cables C and C, may naturally reverse their directions as from any other position on the span, from the bottom point of the load, as a function of the differences in level between the two moving objects.

A reversing device, whereof different variants of embodiment are illustrated in FIGS. I2, 13 and 14, ensures that minimum tensions are maintained on the operating cables C and C not tensioned by the load. In these FIG., the members for compensating for cable-lengths have not been illustrated in detail for the sake of clarity in the drawing, and are designated As FIG. 12 shows, the two winches U and U for winding and unwinding the cables C, and C driven by two motors F and F are linked to one another by a reversing gear N; on the shaft of the winch U (or of the winch U there is a clutch S enabling the two winches to be disengaged. The cables C and C are equipped with auxiliary tensioners H and H, of any type, calibrated to the desired minimum value of tension on these cables when they are not tensioned by the load.

Displacements of the tensioners H H are limited by upper safety abutments h,, h; and lower safety abutments b b When the clutch S is disengaged, the two winches can operate separately, which facilitates placing the cables C and C, in position during preparation for a transfer operation.

The clutch 8 being engaged, and power being supplied to the two motors F F in parallel, the winding and unwinding speeds of the two cables are the same.

When the load leaves the station A for the station B (FIG. 10), the cable C is tensioned by the component of the load P greater than the tension imposed by the tensioner H and the latter is brought into contact with the upper abutment '1 the cable C being tensioned only by the tensioner H,,, which approaches its lower abutment b,,. When the load approaches the bottom point of the span, the tension on the cable C decreases, and as soon as it is lower than the tension defined by the tensioner H the latter leaves its upper position h During this phase, the two motors F and F have been acting as holding brakes.

When the load P has passed the bottom point of the span, the cable C becomes the driving cable. Under the action of the component of the load P, the tension on the cable G, exceeds the value imposed by the tensioner H,,, which comes into contact with its upper abutment h while the tensioner I-I of the cable C drops towards its lower abutment b and maintains the minimum tension provided for on this cable.

FIG. 13 is a partial view extracted from FIG. I2, showing a first variant of embodiment of the link between the two winches U, and U Besides the clutch S on one of the shafts of the winches U and U there are clutches S and S, on the shafts linking these winches to their motors F and F,,. This arrangement is more particularly applicable in the case in which it is difficult to put the two motors in parallel,

When the clutch S is disengaged and the clutches S and S, are engaged, the two winches are independent, and allow the cables C, and C, to be easily placed in position. The clutch 5 being engaged, and only one of the clutches S and 5,, being engaged, only that motor which is not declutched from its winch drives the two winches for winding and unwinding the cables C, C I

FIG. 14 is likewise a partial view extracted from FIG, 12, showing a second variant of embodiment of the link between the two winches U and U The two winches, driven by the motors F, and F are linked to the planetary gears g, and g, of a differential C whereof the cage S, is equipped with a locking brake g,. According to whether the brake g, is released or applied, the two winches can operate independently or, if the two motors are coupled in parallel, the said winches can unwind and wind the two cables simultaneously. This arrangement can exhibit the advantage with respect to arrangements using clutches that the combination of movements is controlled with respect to a fixed element belonging to the brake.

The different-arrangements according to FIGS. l2, l3 and 14 may be used in compensating for variations in length of the cables by differentials according to H057, 8 and 9, the auxiliary tensioners H and H, for the cables C, and C, being disposed where the cables enter the unit K containing the members for compensating for cablelengths at the station A; the declutchable reversing mechanism is then inserted between the two motors F 2 and F FIGS. l5, l6 and 17 relate to a repeater for the positions and movements of the load between the two moving objects.

The appliance for carrying out transfers between two moving objects A and B shown diagrammatically in FIG. 15 comprises a carrier cable C, on which there moves a carriage l supporting a load P, and two operating cables C C attached in opposition at 3 to the carriage 1.

On the moving object A, the three cables are attached to three winches U,, U, and U respectively; the governor station for the winches on the moving object A comprises, as described above, a device (K) for compensating for variations in length of the three cables due to relative movements of the two moving objects, a device (N) for interconnecting the two winches U U of the operating cables C C and a device H for compensating for sag in the cables. On the moving object B, the carrier cable C, is secured at 2, and the operating cable C, is guided over two pulleys 4.

The number of revolutions carried out by the winch U, in order to secure the cable to the moving object B gives an indication of the instantaneous distance E, between the two moving objects; likewise, the number of revolutions carried out by the winch U while the carriage 1 is moving towards the moving object B gives an indication of the instantaneous distance E between the station A and the load P. The distance is the image of the distance to be traversed by the load until it arrives at the moving object B.

The distance E,, and consequently the distance E,E being variable as a function of the relative movements of the two moving objects, it is necessary to know the instantaneous distance E,E for the purpose of accurate and possibly automatic control of the speeds of arrival at the moving object B,

knowledge of the distanceE being itself useful in controlling arrivals at the moving object A.

FIG. 16 shows one particular form of embodiment of a repeater according to the invention, enabling an indication to be given at any instant of the true distance to be traversed by the load before it arrives at one or other of the two moving objects.

The repeater illustrated is applicable to the case of compensation for variations in the lengths of the cables by means of a link via differentials between the winch of the carrier cable and the two winches of the operating cables (FIG. 9).

Only the link via a differential Q between the winch U, of the carrier cable C, and the winch U of the operating cable C is illustrated, the cable C being the cable which returns the load to the station A. The diameter of the winch U, is twice that of the winch U The shaft of the winch U, is linked via a reversible reduction gear L, to the planetary gear v, of a differential V whereof the planetary gear v is linked via a train of reduction gears L to the shaft of the winch U The cage of the differential V carries a posting disc R, cooperating with a fixed pointer r,. A posting disc R cooperating with a fixed pointer r,, is centered on the shaft of the planetary gear v so as to be capable of rotating on this shaft. This disc is driven via gearing L,, at half the speed of the planetary gear v The reduction ratios in the gearings L,, L and L,, are so chosen that the angular movements of the discs R, and R are equal for the same lengths of winding and unwinding the cables C, and C,. A clutch P, enables the winch U, to be disengaged from the winch U, for the purpose of preparing for a transfer operation.

Posting of the movements and positions of the load P with respect to the two moving objects is shown in FIG. 17.

The discs R, and R bear scales in distances whereof the zeros are opposite to the pointers r, and r when the cables are fully withdrawn by the winches U, and U that is to say before preparing for a transfer.

Before a transfer. the carrier cable C, is unwound, and the pointer r, indicates on the disc R, the length E, unwound, and also any variations which there may be in this length, the zero of the scale on this disc being at 0,. The zero of the scale on the disc R has remained opposite to the pointer r When the load is launched towards the moving object B, the disc R, is driven in the reverse direction by the winch U the load is arriving at the moving object B when the zero on the disc R, has returned opposite to the pointer r,, stoppage of the operation having been kept under control by observation of the decreasing angular displacement between the zero of the scale and the pointer r,. At the same time, the disc R has rotated through the same angle and in the same direction as the disc R,, and the pointer r indicates the instantaneous distance E, on the scale on the disc R whereof the zero is then at O For an operation in the opposite direction, displacement of the load is controlled while observing zero on the disc R returning towards the pointer r arrival corresponds to zero on this disc coming opposite to the pointer r,; the pointer r, again indicates the instantaneous distance E, on the disc R,.

This method of posting is independent of the amplitude and duration of variations in the distance E, since every variation reacts instantaneously on the angular displacement of zero on the disc R, for transfers of the load to the moving object B, and on the angular displacement of zero on the disc R, for transfers in the opposite direction.

The repeater furthermore makes it possible to fix the start of deceleration of the load before it arrives at the two moving objects.

For this purpose, fixed or adjustable markers such as k, and k are arranged on the disc R, and R so as to be at definite angles such as a, and a,, which may or may not be equal, to the zeros of the scales on these discs.

The arrival of these markers opposite to the respective pointers r, and r will indicate that the desired periods of deceleration should be started.

The repeater described above is applicable to a transfer device wherein compensation for variations in length of the cables is provided by pulley-blocks on the cables. In order to take into account the lengths of cable in the pulley-blocks, the positions of the pointers r, and r may then be adjusted in order to bring them opposite to the zeros of the scales on the two discs.

Such a possibility of adjusting the positions of the pointers r, and r furthermore enables account to be taken of slight variations in the length of the cable C due to the compensator H for sag in the operating cables.

Instead of the provision of angular posting on discs such as R, and R the relative angular movements of the cage v, of the differential V and the angular movements of the disc R may be transformed, for example by means of toothed racks, into rectilinear movements of the two scales with respect to the reading pointers.

Likewise, instead of posting by directly reading the relative positions of the disc R, and R by means of the pointers r, and r these two discs may take the form of cams cooperating with angular-position detectors such as d, and d of any type transmitting instruction pulses to a regulator R which groups the manual or automatic control members for the successive operations of launching, transfer and arrival.

FIG. 18 relates to a variant of embodiment making it possible to simplify the operations intended to make the appliance work under the conditions required for the operations of arrival at the two moving objects.

Management of the winches u and 14,-, of the operating cables C and C is as described above for the case in which compensation for variations in cable-lengths is carried out by means of differentials intended to apply to each of the two winches a definite fraction of a constant torque for tensioning the three cables which is applied to the winch of the carrier cable C The winch u of the operating cable C which acts in the direction of returning the load towards the moving object carrying the winches, is linked to the planetary gear q, of the differential Q whereof the satellite-carrier cage q is driven by the motor F Likewise, the winch of the operating cable C,, which acts in the direction of displacing the load towards the other moving object, is linked to the planetary gear q, of the differential Q whereof the satellite-carrier cage q is driven by the motor F Finally, the winch u, of the carrier cable C, is linked to a torque-motor F, which applies a constant torque to it.

The winch u, is linked to the satellite-carrier cage w, of a differential W by gearing w, whereof the step-up ratio is equal to the ratio between the diameter of the winch u, and the equal diameters of the winches 14,, u,,. The planetary gear w of this differential is linked on the one hand via a shaft w, to the planetary gear q: of the differential Q and on the other hand by way of a clutch P to a shaft W5 linking the planetary gear W6 of the differential W to the planetary gear qof the differential 0 this shaft being equipped with a locking brake 1",. On the shaft w, there is a clutch w enabling the differentials W and Q to be disengaged from one another.

In order to place the carrier cable C, in position between the two moving objects, the brake F is locked and the clutch w, is disengaged in order to enable the cage w of the differential W,, and consequently the winch u, of the carrier cable, to rotate freely. The winches u, and u; may be used separately in order to place the operating cables C and C in position and under tension.

When the carriage supporting the load has arrived at the moving object carrying the winches, the brake f remaining applied, the clutch p being disengaged and the clutch w being engaged, the cables C, and C are allowed to vary in length, due to relative movements of the two moving objects, by the cable C being unwound or wound up twice as much as the cable C,. At the time of launching the load by the cable C, being unwound and the cable C being wound up by their respective winches u and u the effects of variations in the length of the cables are cancelled out by play in the differentials W and Q,,, the load moving at the speed regulated by the winches a and u The same applies when the load is arriving at the moving object under consideration.

In order to bring the load up to the opposite moving object, the clutch I is engaged and the brake f, is released; the planetary gears w and w of the differential W then being fast with one another, the shafts w and w, are driven in the same direction by any rotation which the cage w of the differential W may carry out, and play in the differentials Q and 0,, allows the load to follow relative displacements of this moving object. The speed of arrival will therefore be that regulated by the winches u and u,,. The same will apply to launching the load from this moving object.

The working conditions of the clutch p and the brake f for arrivals and launchings at both moving objects may be reversed with the load substantially half-way in both directions, without for that reason interrupting displacement of the load by the winches u, and u This reversal may be carried out automatically by means subject to control for example by the winches u, and u The arrangement described above thus enables loads to be brought up to each of the two moving objects simply by combined operation of the brake f and the clutch p independently of variations in the length of and tension on the cables in the course of an operation.

FIGS. 19 and 20 relate to a variant of embodiment for a transfer appliance comprising two cables.

The diagram in FIG. 19 shows the two winches u u of the two operating cables C and C attached in opposition at 3 to the load-carrier carriage l which runs on the cable C The two winches u and u; are carried by the moving object A, and the moving object B carries the deflector pulleys w for the cable C The winch u is linked to the planetary gear q, of a differential Q whereof the cage q is driven by a motor F by way of gearing L and a nonreversible worm mechanism l the winch u is linked to the planetary gear q, of a differential Q whereof cage (1 is driven by a motor F by way of gearing L1; and a nonreversible worm mechanism i The planetary gears q of the differentials Q and Q are linked by shafts W and W respectively to the planetary gears w and w of a differential W whereof the cage is linked by gearing w to a torque-motor F,.

The shaft w is equipped with a brake f and a clutch p which enables it to be made fast with the shaft w,, itself equipped with a clutch w The shafts n and n of the two worm mechanisms l and are linked to one another by a reversing gear N,, the shaft n being equipped with a clutch S In order to place the cable C in position between the two moving objects A and B, the clutch w is disengaged and the brake f is applied; as a result of play in the differential the winch u which is then free, allows the cable C to unwind.

The load-carrier carriage being on the moving object A carrying the winches, the torque-motor F, applies tension to the cable C; by way of the winch u the clutch w-, being engaged, the clutch P being disengaged, and the brake f remaining applied. Variations in the distance between the two moving objects will have the effect of causing the winch u to wind up or unwind the cable C to the extent of twice the variations in distance. I

For operations of launching the load P by the moving object A, the two winches u, and u are driven via the differentials Q and 0 by the motors F and F interconnected by the clutch 5 the distance between the load and the moving object A remains that governed by the winches, whatever the variation in distance between the two moving objects. The same applies I as regards operations of bringing the load up to the moving object A.

Before operations of arrival at the moving object 8, the brake f is released and the clutch 1:2 is engaged. The tensioning torque is then distributed to the two winches a and u by the differential W, and variations in the distance between the two moving objects have the effect of causing the two cables C and C to be simultaneously wound up and unwound to the same extent; the distance between the load and the moving object B remains that governed by the two winches. The same applies to operations of launching the load from the station B.

When the load-carrier carriage has arrived at the moving object A, disengagement of the clutches w 1 and S enables the motor F1, to rewind on to the winch u the unwound length of the cable C between the two moving objects.

if the winding capacity of the winch u: is made twice that of the winch 14,, and if the winch 14 is used for placing the cable C in position between the two moving objects and for returning this cable to the moving object A, all the operations of a transfer may be carried out without any need for readjustments to windings on the two winches.

lclaim:

1. Device for compensating automatically for variations in the tension and length of cables for transfer of loads between a moving sending ship and a moving receiving ship having a carrier cable extending between said ships, a trolley moving on said cable, said trolley carrying the load, an outhaul cable, an"

inhaul cable, said outhaul and said inhaul cables controlling the movements of said trolley respectively between said receiving and said sending ships, a winch for each of said cables, a motor for each of said winches for rotating the respective one of said winches in both directions, said winches for said inhaul and said outhaul cables being rotated in opposite directions and at equal speeds for control of the movement of the load and means for compensating for the length and tension on said cables, said winches, said motors, and said compensating means being mounted on said sending ship, said compensating means including a first mechanical control device for control of the position of said trolley with respect to said receiving ship controlling the winding in and the paying out of said carrier cable and of said inhaul and of said outhaul cables to lengths substantially equal to the changes of the distance between said stations, a second mechanical control device for control of the position of said trolley with respect to said sending ship controlling the winding in and the paying out of said carrier cable to a length substantially equal to the variations of the distance between said stations and to a double length of said outhaul cable, means for selectively blocking said control devices, each of said control devices including separate means for winding in and for paying out each of said cables controlled directly by the variations of the distance between said ships independently of the movement of said trolley, said winding in and said paying out means of each of said control devices being conjugated and subjected, in the directions of the tension on said cables, to a common constant value return force.

2. A device as described in claim 1, said control devices including a pulley for and receiving each of said cables and a constant cable-tension load on said pulleys,

3. Device as described in claim 1, said control devices including two'differentials coupling said winch for said carrier cable to said winches for said operating cables, said differentials applying to each of said winches for said operating cables a definite fraction of a constant torque for tensioning said cables, said constant torque being applied to said carrier cable winch by a reversible torque motor.

4. A device as described in claim 3, said winches for said operating cables being interconnected by a reversing mechanism declutchable for individual movements of each of said operating cables.

5. Device as described in claim 3, including an auxiliary tensioner for each of said operating cables providing a minimum tension on the respective one of said operating cables when not under tension by the load during transfer, each of said auxiliary tensioners being disengaged by tension on the respective one of said operating cables.

6. A device as described in claim 3, said winches of said operating cables being each coupled to a differential, a satellite carrier cage for each of said differentials driven by the motor of the respective one of said winches, said differentials being coupled to a third differential, a satellite-carrier cage for said third differential coupled to said winch of said carrier cable, planetary gears for said first named differentials connected by a clutch, a locking brake for said planetary gear of said differential of said winch for said operating cable which moves the load toward said sending ship, said clutch and said brake being interconnected for selective operation at arrival of the load.

7. A device as described in claim 6, including a clutch disposed between said differential coupled to said carrier cable winch and said differential of said winch for said cable displacing the load away from said sending ship.

8. A device as described in claim 7, including a repeater for the positions and movements of the load, said carrier cable winch and said winch of said cable moving the load toward said sending ship being respectively coupled to two planetary gears of a differential, a cage for said last named differential, a scale actuated by said last named cage posting the instantaneous distance from the load to the receiving ship and a second scale actuated by the rotation of said operating cahle winch posting the instantaneous distance from the load to the sending ship.

ferential, said two differentials being connected to said third differential and a torque motor connected to said third differential applying a torque for tensioning said cables.

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