CA1210644A - Funicular transport apparatus with a double endless cable and speed variation - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

The present invention provides a transport appara-tus of a funicular type, comprising a series of mobile units travelling along a looped path characterised in that each mobile unit is permanently engaged with a first cable which produces a variation in the speed of displacement of a mobile unit which is connected in an intermittent manner to a second cable which provides the traction for the series of mobile units.

Description

~ ` lZ3 (~'644 e present invent;on relates to a variable speed, c~losed ~rcuit transport apparatus.

Transport apparatus comprising a series of permanent-ly attached mobile units has been known since the ~irst tramsways -hooked on to a cable and includes modern cable-carrailways.

These systems today present a major disadvantage:
the mobile units (chair, car, container) which are intended to transport passengers or merchandise must, at the entry to the station, before the slowing down or stopping thereof, be disconnected from the cable or a chain which constitutes - the drive element of the apparatus.
~ c~a~;~ n Consequently, in the embarkation or cl~wing do~J
zones, the mobile unit leaves a programmed motorised arrange-ment and becomes attached to a different arrangement: for ,example the mobil~ unit leaves the cable which embodies the pneumatics and becomes attached to a very slow moving cable.

More recently apparatus has appeared in which the mobile units remain always firmly attached to the basic drive arrangement, that is to say to a variable-speed funicu-lar. These systems have a chain with a link of variable length. The variation in the length of the link assures a variation in speed. Nevertheless such systems are also limited:

- By the fact that the tension on the belt varies in an inverse manner to the speed. For example, if the variation in speed is from 1 to 10 the tension on the belt at low speed will be 20 times as great as the tension at high speed. Consequently, it is necessary to dimension alll the members and the-variation belt for tensions in the speed zones and accordingly, to provide parts over-dimensioned and bulky in the high speed zones.

~ ~ Z~644 - By the fact that in the closed loop circuit the variable element must transmit the orce of traction for the whole length of the circuit, both in the zone of de-celeration and in the zone of high speed.

- By the fact that the apparatus for fixing or clamping a mobile unit to the chain must ~e designed for pulling all the mobile units so that dimensions are propor-tional to the length of the circuit and the number of mobile units.

Apart from the particulars of the case the trans-port systems of the "funicular" type have never been capable of intensive development, as apart from their advantages they present inconvenient drawbacks:

- When the mobile units change cables they jerk upon acceleration and problems of strength and safety arrise due to the repeated connection with and disconnection from the cables.

- When a system employing a chain of links vari-able in length is used, the funicular is at the same time the traction means and speed variation means. There are then the problems of cirulating and tensioning of the cable, the take-up of the drive, the traction and the braking.

The present invention has in view the mitigation of the disadvantages above-mentioned and the provision of an apparatus which preserves the advantages of the kinematics of the funicular.

According to the present invention there is pro-vided in a transport apparatus of the type comprising a series of mobile units constrained to move along a closed path having high and low speed zones, the improvement wherein ''.'',, ,~;~
.~. t.

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the mobile units are permanently interconnected by link means which permi~s the speed of the mobile units relative to each other to change according to whether they are in a high or low speed zone, a continuous extended drive means is arranged along part of the closed path, and means are provided for engaging the mobile units with the extended drive means when they travel along the high speed zones of the closed path.

In a preferred embodiment, the cable which varies the speed is constituted by a device forming a chain having links of variable length which determine the spacing between two successive mobile units, thus permitting the maintenance of the speed of the mobile units of the system. This chain only transmits the tension necessary to draw the mobile units in the zone of variable speed, and not otherwise drive i the units.
i I The invention will now be described in more detail, by way of example only, with reference to the accompanying ¦ drawings, in which:-Figure 1 represents diagrammatically a funicular ! according to the invention comprising a traction cable and a speed variation circuit which make up a mode of transport;

Figure 2 shows a modification of the funicular mode of transport;

Figure 3 is a side elevational view of a system comprising a train of mobile units equipped with pulleys;
, Figure 4 is a side elevational view corresponding to the arrows V-V (Fig. 5) showing a modification of a chain of ~he "deformable link" type;

Figure 5 is a plan view of the modification shown F in Figure 4;
, - lZ~0644 Figure 6 illustrates the general arrangement of - 3a ---- lZlQ649L
~ the funicular;

Figure 7 shows an arrangement for .s$nsing and F regulating the tension in the speed variation ~ , Figure 8 illustrates the regulation by measuring the force applied by a mobile unit on a stationary ramp;

Figures 9 and 10 are perspe~tive views, respectively a side view and a view looking upwards from below of another modification of the circuit;

Figure 11 is a side elevation, partly diagrammatic of a transport arrangement according to a modification of the invention;

Figure 12 is another side elevational view of this arrangement;

Figure 13 is a diagram of the speed related to Figure 12;

Figures 14 and 15 are further elevational views showing a portion -of a further modified transport arrangement according to the invention;

Figure 16 represents a cross-section on line X-X
(Fig. 15);

Figure 17 is another side elevational view of a portion of a further modified transport arrangement;

Figure 18 is a fragmentar~ view on an enlarged scale of a pair of toothed wheels shown in Fig. 19;

Figure 19 is a view showing two pairs of toothed wheels;

lZlU~
- - Figures 20 and 21 are side elevational views of further modified transport arrangements;

Figure 22 is a speed diagram corresponding to Figure 21; and Figures 23 to 26 show portions of further modified transport arrangements.

- lZl(,'644 Figure 1 represents a transport system employing funicular kinematics. It comprises an endless chain of links 1 of variable length. Each link carries a mobile unit

2 which is an integral part of the chain. The transport system is completed by a continuous extended drive means, for example, a traction cable 3 loopeed upon itself, and driven at a constant speed (equal to the maximum speed of the mobile units 2) by a motor drive 4 of known type.

While the funicular of Figure 1 may comprise a zone DA of maximum speed and a zone which includes the deceleration section AB, the section BC of lowest speed (or .
standstill) and the acceleration section CD, Figure 2 illustrates a circulatory arrangement whexe the varia~le chain 1 cooperates with several sections of traction cable 5,6,7 each looped on itself. The traction cables leave free between themselves spaces corresponding to the variations in speed of the mobile units between stations g,l0,11.

In the two cases, the traction cables do not extend only into the zones of maximum speed; the mobile units are at that time attached to the two circuits of variation and traction. On the contrary, in the station-ary zones lvariation of speed) the mobile units are dis-engaged from the traction cable, as illustrated in Figures 3 to 5 and 10, when they remain attached to each other.

A primary advantage of a transport system accord-ing to the invention lies in the fact that the motive power is applied simultaneously to each of the mobile units 2 situated in the zones of maximum speed. This tractive effort is assured by the traction cable and not by the chain 1. The elements which join the links of variable length may thus be standarised. In particular they do not have to be adapted to the length of the specific circuit or to be designed for the pull at slow speeds.

,~ - 6 -121~64~

Figure 3 shows a portion of a transport system in which the successive mobile units are constituted by the bogies Bi, Bi~l...whereas the upstream bogie Bi is linked to the precediny downstream bogie Bi+l by a variable transmis-sion cable 8, which runs over the pulleys downstream and up-stream, respectively of the upstream and downstream \ - 6a -Z1~644 bogies. In other respects each pulley has a device for controlling its rotation consisting of plate-carrying rollers 12 and 12a adapted to strike against the ramps 13 fixed to the framework of the system accord-ing to the invention and disposed in the variable speed zones.

The movement of the mobile units which proceeds from left to right (dir-ection of arrow 15) is represented on the drawing (Figure 3) at the beginning of a deceleration zone. Each bogie Bj is mounted on a clamping bracket Pj for its intermittent association, by friction, with the traction cable 3. The mobile unit Bj circulates at a con-stant high speed. It is firmly attached, by its bracket Pj to the cable 3 which moves along at a constant high speed. The bogie or mobile unit Bj~1 downstream has entered the deceleration zone. Its clamping bracket Pj+1 has opened under the action of a control mPchanism of known type, not shown, and placed at the entrance to the station (Figure 6). The bogie Bj~1 is d~sconnected from the cable 3, but remains attached to the funicular assembly formed by the train of bogies and by the variable transmission cable 8.

In this deceleration zone, the pulley bj+1,1 is entrained in rotation in the direction of the arrow 18, by the action of the ramps on the rollers 12 and 12a, the pulley turns the variable transmission cable 8 on itself and the length of the link M defined by the distance between the brackets Pj and Pj+1 diminishes.

In the embodiment of Figure 3 the pulleys upstream and downstream are shown of a bogie which gears them together. In other respects the traction cable 3 passes all the length of the line; it is further seen (Figures l, 6) that this cable may leave free the variable speed zone.

Another construction of a system according to the invention is illus-trated in Figure 4 (medial side elevation) and Figure 5 (plan view).
The traction line 3 runs at an elevated constant speed from left to right . It carries, at regular intervals, means for articulating a pair of dogs tl1 and tj2 mounted on rollers 19 for rolling or sliding on the ramps 20 of the fixed framework of the transport system, and of l'Z~ 644 bearing surfaces 21 which prov;de the members for positive associat;on between the traction cable and a chain of deformable links. The mobile units of the system are the cross pieces Tj which carry in known manner the return rollers for the cables or bands 22, closed on them-sè1ves, each of constant length, as the supporting means on the lateral ramps 23 located in the zones of speed variation. A chain of deformable links Mj (Figure 5) is formed.

Figures 4 and 5 show a deceleration zone. The cross pieces Tj_1 and Ti 9 round at a constant high speed in the direction of the arrow 15A. They are firmly attached by the dogs tj~1 and tj,1 to the traction cable 3 which runs at a constant speed. The cross piece T
has entered a phase of decleration; the dogs tj+1, are open. The cross piece is disconnected from the cable 3, its two opposed cheeks opening apart under the action of the ramp 23 against which ~he rollers 24 come to abut and roll. The mobile unit Tj~1 remains ~oined to the funicular assembly of successive cross pieces by the band 22 which form a link of constant perimeter. In the zone of Figures 4 and 5, the link Mj+1 is deformed by widening out, but becoming shorter, where the cross member Tj+1 slows down.

The advantages of the transport syst~m described are numerous.

- That the mobile unit may or may not be attached to the traction cable, it may be at a constant speed or at a variable speed which may be high or low, it always remains firmly attached to a system of an end-less chain of links of variable 7ength, this system programming invar-iably the spacing of the mobile units with the preceding and following units. Thus, the "pace" of the transport system is automatically preserved, all individual adjustment of the speed or lengthening of the links being afterwards superfluous.

- The mQbile unit need never be free, the safety provisions may be extremely simple.

B

~Z~6~4 , - All the forces concerning the traction, the braking, urgent stopping, adjusbment, are effected on a single l;near traction element, so that the elements of thetchain of links of variable length (which constitute ~ c ~rc ~
1~ the variable b~ ) d~ not have to be oversized, but compact. Moreover.
c~c~ ~
the variable baR~ does not transmit the tension necessary to pull the mobile units in the variable speed zones, this tension being taken up in the zones of high speed, by the endless traction ~}q~, and which may easily be amply dimensioned.

- The funicular system according to the invention does no~ transfer any work or heat with the exterior. The funicular, turning on itself, does not dissipate, except for friction, energy for deceleration of the mobile units, whatever may be their weight and speed. Similarly ;t is capable of accelerating and then decelerating any weight without dissi-pating any energy other than that of friction, the sole requirement being that the weight may leave the system at the same speed as that with which it has been loaded on.
.
The funicular kinematics, looped on itself forms, according to the in-vention, a mechanical assembly susceptable at all points of the loop, to pre-programming of the speed, this assembly proceeding cyclicly through the same stages. A transport system is thus provided in which no incident-of a contingency character is to be envisaged (apart from breakage of a mechanical member or personal accident).

- Each element of the chain is under tension, and a clamp acts only on the mobile unit to which it is applied.

Figure 6 shows the general arrangement of a funicular according to the invention. The mobile units are moving from left to right and they are represented by a train of bogies Bj such as above described, firmly attached to the variable speed chain 1. In this embodiment the features characterising the invention are employed according to which the succ-essive mobile units are disconnected from the traction cables 5 or 6, in the zone 9 of the station, said zone, corresponding to the speed varia-tion. The traction cables 5 and 6, each-being endless, are entrained by motor mæans 25 oF known type, at a constant high speed. They operate ~' .
D g - 121Q64~
only in front of the sections A'A and DD' where the chain 1 circulates at constant high speed, while leaving free between them the zone 9 of speed variation, which means there are three sections:

- a section AB of deceleration;
- a section BC of low speed, or even stoppage;
- a section CD of acceleration.

At the entrance to zone 9 a device for opening the clamps at 16 is provided, and at the exit to zone 9 a device for closing the clamps Pi...Pj+n at 17.
.
The operation and movement of the system in the portion of the circuit illustrated in Figure 6 take place in the following manner:

.
The bog;es Bj_n and Bj_n_2, always in the high speed zone, are firmly attached to the traction cable 5.

On reaching the position of device 16, the bogie Bj_1 is released from the cable 5 (opening of the clamp Pj_1) to enter into the deceleration zone AB. The ramps 13 and the rollers 12 of this bogie cause the up-stream pulley bj~ to turn in the direction of arrow 18 lFigure 3).
The pulley moves the variation cable 8 and the distance between ~i-2 and Bj_l is lessened in step.

The bogies Bj and Bj+l are then in the low speed section BC.
' The bogie Bj+l is shown in the acceleration stage, its pulley bj+2 2 refastened by the variation cable 8 to the preceding bogie Bj+3, wind-ing off the cable under the action of the acceleration ramp.

¦ The bogies Bj+3, Bj+n having cleared the zone M for closure and recovering the high circulation speed of the traction line 6 are refastened to the latter.

Thus, there is not a continuous traction cable, but a series of traction cables formed as closed loops.

B lo 1.

lZlU644 Advantageously such a system avoids an abnormal increase in tension in the variatîon cable 8 at low speed. To this end the traction cable is stopped as soon as the mobile unit is disconnected from it. To the possible anchorages of the clamps P; which intermittently refasten the mabile units to the variation ~ ~ere may be introduced, without di,fficu~ty, a certain increase in tension at high speed in the variation . In fact, one part of this tension in the high speed zone is taken up by the traction cables, on the other hand, the funicular according to Figure 6 comprises a simple regulating device, illustrated in Figures 7 and 8 and having for the object:

- The interconnection of the motor means 25 of each of the looped traction cables.
.
- The individual control of these means so that the tension in the variation cable never exceeds a predetermined value, very low, at the entry to ~ deceleration zone. If this tension is F, the tension at a speed K times smaller will never exceed the value KF, which remains small.
.
In Figure 7 is shown a zone of speed variation between two zones of high speed circulation of the funicular analogous to the representation in Figure 6; The motors 25 of the traction cable loops 5 and 6 are connected to one another by a system of regulation and control which comprises, for each motor:

- A tachometric dynamo 26.
- A device 27 to measure the angular amount out-of-step.
- A speed controller 28 .
- A speed regulator 29 with four quadrants which control one or other of the motors 25.

The regulating system is completed by:

- An indicator 30 of the speed of rotation.
- A sontroller 31 of the angular position.
- A supply circuit indicated diagrammatically at 32.

.

-~ lZ~Q644 The purpose of this regulating system is to limit the tension in the variation cable. The value of this tension is detected by means of the device illustrated in Figure 8. The bogie 13 in the stopping station or low speed zone (corresponding to section BC in Figure 6) is connected to the bogie which follows and the preceding bogie by the variation circuit 8, which runs around pulleys Bi carrrying the rollers 12 and 12a which strike against the ramp 13a which forms part of the stationary structure of the system.
As a result the tension exerted on the variation cable 8 will decrease, recorded and regulated by the force exerted on the ramp 13a, the measure effected by a known device represented at 33, for example, by a pick-up detector. As soon as the force on the ramp exceeds a predetermined value, the regulating system (Figure 7) gives the instruction by a motor Z5 to the txaction cable 5 at the entry of the dece-leration zone AB (Figure 6), to decelerate for a given time or to carry out a supplementary rotation to restore the tension to the desired limit.
From an inspection of Figures 7 and 8 a system of systematic regulation exciting the motor 25 of the traction line 6 at the exit of the acceleration zone may be readily understood, this being for two reasons: First, it is evident that the tension may not be regulated so as each time to increase the speed of cable 5, as this would con-stantly increase the speed of the system. It is necessary to have an interconnection between the motors 25 of the traction cables 5 and 6 to realise an overall regulation at a mean speed for the funicular assembly. Secondly, the transport system of the invention must, conforming to the legal requirements for the security of transport, provide a system for urgently braking stopping. To avoid increasing the tension of the variation cable at low speed there must be, by the regulation, a balance of braking between the traction cables 5 and 6, which practically smooths out all ~ - 12 -braking and stopping forces.

The ~udicious disposition of the loops of the traction cable in the arrangement of the invention avoids all increase of tension in the variation lines besides affording to the system, during its normal operation, braking and urgent stopping facility.

~- 12a -~Z1(.'644 ~ It is readily understood that modifications in detail in the funicular type of transport system according to the invention~ or to its system for regulating the tension in the variation ~ on condition that the re~ulation provides an interconnection between the motor means of the ehdless tension bands, do not depart from the scope of the invention.
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Another preferred embodiment is illustrated in Figures 9 and 10j the station zone (or zones) is provided at the ends of the loops formed by the traction cable. It is seen that the variation chain 1 follows, in the end zones E, a path E1 E2 which substantially avoids that of the traction cable 3 round the motor wheel 4. This condition is allied to that of Figure 1, with the difference that the station zones are located at the extremities of-the track of the system.

It is seen that, conforming to the invention7 the traction cable leaves free the end zone E which is the zone of variation of the speed of the mobile units 2 attached to the variation band 1. The mobile units are each equipped with a clamp device 40 intended to effect their inter-mittent association with the traction cable (Figure 10). If it is con-sidered that the sense of movement of the mobile units as indicated by arrows 41, the clamps are made to open when the mobile units arrive at the entrance to section R1R2 for connection with the variation band. The mobile unit is then unfastened from the traction cable and follows the track of the variation band, passing through a zone of deceleration, a stopping zone or low speed zone and an acceleration zone (in Figure 9 these zones are respectively indicated by letters D, PY, A). Finally Lhe mobile unit arrives at the second section of adjustment R'1R'2 where its clamp is made to close on the traction cable. The mobile unit (2) may then re-enter the high speed zone GY along which it is firmly attached to the two cables of variation and traction (Figures 9 and 10).

In this embodiment there is thus a single endless traction cable and a single variation cable. The paths of these two elements are spaced apart at the ends of the loop which defines the length of the track of the transport system. Only one end zone is shown. The speed regulation at the opposite end of the track may be similar or different according B
_ 13 _ - - to t~e path followed by the variation band (chain) and the mobile units which are attached thereto.
.
In the following description the term "STATI~N" (Figure 11) denotes the path travelled by an attached ~obile unit of a bogie B between the moment when this bogie comes to leave the traction cable 50 and the moment where it is reattached to this traction cable. Between the two mnments, the b wie in question will have travelled succlessiv~ly a deceleration zone 51, a low speed zone 52, and a docol~r ~ zone 53.
On both sides of the station are formed high speed zones 49. Parallel to the layout of the traction cable 50 and variation cable 54 is drawn a diagram 55 of the speeds.

In the foregoing a system of ramps and rollers has been described which in the various zones of deceleration or acceleration permit the unwinding or rewinding of the variation cable to carry out whatever programme of speed is predetermined by the construction of the ramps.

The examples of systems for regulating the tensions of the variation cable at low speed have been described thus far involving a member which may be located before the station. These systems may act essentially on the driving motors of the sections of the traction cable.

The novel examples of the arrangements for regulating the tensions given below are peculiar in that they act in the-station itself without influencing what mode of driving motor or motor speed there may be.

One example of such a regulating arrangement is illustrated in Figure 12 which is place in co-relation to the speed diagram of Fisure 13. In this case there is utilised regulating means capable of displacing towards the upstream the position of the point 56 where the bogie is reconnected to the traction cable SO. The bogie Bj is then seen to grasp the traction cable 50 by its clamp 57 before the end of the accel-eration zone 53 where the ramp 58 unwinds the variation cable 54.

The curve 59 of the speed diagram corresponds to the speed variations obtained by the ai~ of the single ramps 58. It is noted that as soon as _ 14 -~Z1~644 the c~amp ~t grasps the traction cable 50, the speed of the bogie is no longer dependent on ~he ramp 58:- the variation of speed then conforms to the new track 60. Assuming that the new track corresponds to a very rapid acceleration such as that of the curve S9, the ramps 58 continue to unwind a certain length of the variation cable 54 after the instant corresponding to the point 56, a slackness is obtained in the section of the variation cable separating the bogie Bj from bogie Bj+l which im~ediately precedes it. This slack takes place to the detriment of the slack present in the variable cable at the level of the station under consideration. Thus, this action enables the variation cable 54 to be stretched again at the level of this station.

In order to detect the sub-tension of the variation cable 54 at the level of the station, any known means may be employed. In particular a detection may be made in the synchronism between the bogies entering a station and those which are leaving.

To obtain a regulation of the instant when the clamp 57 marks the traction cable 50 action may also be taken on the position of the ramp which effects the opening of the clamp 57 since the clamp remains closed until it is subjected to the action of its return spring.

A simple combination of known means permit in this way the desired regulation to be achieved; the detection of the delay of a bogie which leaves a station draws back the ramp intended to maintain ~he clamp open. The greater the delay, the more this ramp is drawn back. The sooner the boie grips on to the traction cable 50, the more the variation cable 54 is tightened in the station concerned.

It is also clear that all slack in the variation cable ~4 entering a station is im~ediately detected, and that the regulating arrangement at once corrects this increase in the slack. There is thus a system of automatic regulation which acts step by step without any modification in the speed of the driving system of the traction cable 50.

According to a variant illustrated in Figure 14, it is advantageous to provide an assembly such that the normal clamping on to the traction cable 50 by the clamp 57 of each bogie has initiated a location 61 fixed - 15 - ~.

~ .

i2~44 in construction before the end of the ramps 58 which control the unwind-ing. The location effective for grasping the traction cable by the clamps may then take the place of the normal or theoretical location 61. To permit this replacement a stationary system is introduced to transfer the slack step by step of one station to the following one, but the act of permitting each clamp to grasp the traction cable 50 downstream-of the theoretical location 61 fixed by construction enables the slack of the traction cable 50 in the station in question to be given in preventing the start of the corresponding amount of slack at the closure of the clamp 57 at the theoretical location 61.

According to another modification illustrated in Figures 15 and 16, the regulating means are constituted by an elastic system such as a spring 62 inserted at the section of the variation cable 54 which separates two consecutive bogies. A predetermined loading is preferably given at each sprin~.

It will be appreciated that an increase in tension which is accumulated little by little in the station will cause compression of the springs 62 in the low speed zone 52 at once at this place the tension in the varia-ation cable 54 will exceed the value of the preloading of the springs 62. Thus a limitation of the tension of the variable cable is obtained.

The system may be improved by associating each spring 62 with two non-return pa~ls 63 adapted to engage in the racks 64. When the pawls are free to act on the individual spring 62 their operative extremities respectively rest in eng~gem~nt with the racks 64 for locking the mechanism and opposing all movement of the spring 62. When the free ends of the p2wls are moved a distance from the racks 64', the pawls are moved a distance from the racks 64 so that the mechanism is unlocked to free the springs for action.

Thus the opening ramps 64' are provided in the low speed zone of each station, but not in the reacceleration zone. The pawls 63 thus prevent the spring 62 from taking its natural position when, in the course of the reacceleration, the tension of the variation cable 43 diminishes in the opposite sense. to the speed. This procedure serves to give slack in the variation cable 54 in the station in question. The ramps are pro-_ 16 -. ~ , ~Zl~6~4 - 'vided at the entry of each station to make the pawls 63 jump at the moment of passing into the deceleration zone. The slack which is given to the variation cable 54 in one station is automatically compensated by an increase of the tension in the same cable in the following station.

In the case where there is a continuous diversion, due for example to a - steep incline in an interval between two stations; the regulating device to be described is less advantageous than those already described: the correction in length is not so quick taking into account the fact that the variation obtained is divided with respect to the extreme speeds.
This device is, on the other hand, advantageous when it involves not more than one weak deviation many times repeated~ but of a rough excess which has caused an objectionable delay of a bogie or a number of bogies.

A numerical example may enable an assessment of the system to be made:
Suppose that a foreign body introduces to the station, on a bogie, a delay of L metres. Suppose moreover that R = Y represents the relation between the h;gh speed V of the high speed zones'49 and the low speed v represents that of the low speed ~one 52. In this case the delay of L metres of the'bogie again in the zone near to the high speed zone is translated immediately by an elongation equal to L of the elastic ~ystem situated at this instant in the low speed Rone 52. Thus the only excess tension of the variation cable 54 which will result in an excess tension corresponding to the excess tension of the elastic system ~or elongation equal to L and the excess tension will be easily lowered.

On the o~her hand the return to normal will only be by fractions of the value L at each bogie passage.

According to another modification illustrated in Figures 7 to 9 the problem of the excess tension of the variation cable 54 may'also be solved, not by play on local variation in the length of the cable, but in locally releasing the variation cable in favour of an entrainment force derived directly from the traction cable by the intermediary of a friction mechanism:

, Th7s type of solution is advantageous, for example, if a mechanical accident such as a roller seizure or the introduction of a foreign body into the mechanism causes a permanent breakdown on a bogie. In this case the extent of the breakage is increased when the bogie begins a deceleration at the entrance to a station, and when this bogie has reached the low speed zone, the excess tension in the variation cable ~4 wlll then be multiplied by the relation R of the speeds of the high and l~w zones.

In practice~ each bogie is provided with two members for connection with the traction cable. The first connecting member is that which ~ttaches the bogie tD the traction cable in the high speed zones, and which may consist, for example, of a pincer-like clamp. The second connecting member is adapted to ensure the frictional entrainment with a variable degree of slip. The intensity of the friction may be requlated according to the excess tension to compensate in such a way that the compensation takes place by a supplementary entrainment force supplied by the traction cable. The term "friction" is used here in its largest sense: in the case of the example illustrated in Figures 17 to 19 a system is found, for example, which clamps the traction cable between two pulleys 65 with a variable intensity of tightness, or a breakage will affect the pulleys on a driving shaft 66.

More precisely, éach pulley 65 comprises two complementary half-pulleys65a and 65b substantially identical and mounted to revolve on the same transmission shaft 66 firmly secured on the bogie Bj under consider-ation. This shaft 66 is non-rotatably mounted on the bogie Bj and a spring actinQ on the upper end of the shaft 66 holds permanently as a slipping clutch between ~he bottom head 67 of the shaft 66 and the friction disc SO. This spring 70 is adjacent to a clevis 71 carrying a roller 72 adapted to act on the ramps 73. A captive device 74 connected with a mechanism for positioning the ramps 73 and the force sensors 75 positioning the ramps 73 so as to counteract more or less the clamping force exerted by the spring 70.

It is understood that in the absence of abnormal excess tension the sensors 75 do not'detect any force sufficiently intense to cause dis-placement of the ramps 73. These ramps remain sufficiently low to 121~644 - 'loosen the half-pulleys 65a and 65b. On the other hand in case an excess tension occurs in the variation cable 54, the ramps 73 are raised more or less so as to leave the springs to act on the mounting to effect an entrainment by friction.

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It is noted that the pulleys 65 preferably carry teeth 76 on their peripheries. The meshing of these teeth ensures a balance of the forces of friction transmitted by the two pulleys.

According to a further example illustrated in Figurès 20 to 22, contrary to the case of Figures 12 to 14 where a regulat;on of tension on the variation cable 54 is obtained by making a kind of connection of the elements of variation cable to the traction cable with an adjustable setti'ng, it is also possible to effect a variation of the setting while leaving unaltered the position of the ramps 77 controlling the closi'ng of the clamps 57. For this it is sufficient, beforehand, ts adjust the set of the variable cable by known means such as variation of the diameter of the winding pulleys of the bogies, variation of the orient-ation or position of the humps and/or the ramps 78 which limit the length of the variation cable unwound.

As may be seen from Figure 22 all this results in very easy modification of the scheme of speed corresponding to the curve 59 either by way of timing corresponding to the curve 79 or by more continuity, conforming to the curve 80.

The mèans for regulating the tension of the variation cable to the invention enables partial saving of the variation cable in avoiding subjecting the cable to very high speeds locally, and on the other hand avoiding sudden jerks in the entrainment of the mobile units, parti-cularly at the moment when each of the units is being reconnected to the traction cable.

The regulation systems which have been described herein entirely protect the low speed zone from excess tensions in the case where the sliding hazards of the clamps may cause the "consumption of the band", that is to say in the case~where between the points of entry and exit to the B

12~Q644 .
station the length of the variation cable available will be much less than the length of the traction cable.

According to the present description the low speed zone is protected from high tension which may have results such as:

- Important multiplication in the rat~o of extreme speeds.
- Excessive friction or seizure of a roller.
- Force due to the condition "chain sag" in the position of the varia-tion cable lying between two successive mobile units.

In this case the invention provides a system for protection of which the working principle may be enunciated as follows: it is arranged for a mobile unit in deceleration always to pull on its trailing cable, or upstream portion, but never on its leading cable, or downstream portion, beyond a certain predetermined limit.

The following examples illustrating the principle of operation above described are given as being non-limitative.

Figure 23 shows portion of a circuit comprising a high speed zone 81, a deceleration zone 82, a low speed zone 83 and an acceleration zone 84, the zones 82, B3 and 84 constituting a station 85. To permit the mode of operation described above the zone of deceleration has been constructed with a downward slope, while the zone of acceleration has been made with an upward slope.

When a mobile unit is in zone 82 the component of the force of gravity 86 obtained by projection of this force on the plan of the circuit is a force 86a directed so as to set up a pull on the mobile unit by its rear cable, this pull relieving some of the tension in the cable in front.
Without the presence of the slope the tension in the cable in front will be found to be mwltiplied in the low speed zone.

Figure 24 shows the same principle applied, but at the level of the end of a looped circuit. The station 87 is located on an inclined ground which confers on t~e deceleration zone 88 a descending slope and to the acceleration zone 89 an ascending slope.

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~ 121Q64~

According to another example in Figure 25, the inertia of the mobile units 90 may be increased either by directly increasing their mass or by indirectly giYing each mobile unit at least one loosely attached inertia wheel for rotation with the roller members 91 of this mobile unit.

In this case it is evident that in each deceleration zone the kinetic energy of the unit, or the wheels contribute to the acceleration of the mobile units in causing a tension in their leading cable, the reverse phenomenon being produced in the acceleration zones.

In the case of the example illustrated in Figure 26 there is arranged all along the zones of deceleration 92 or on part of these zones a linear motor 93 of the type in which the pulleys 94 are located in the fixed part whereas induction means without pulleys is located in the mobile unit 95.

It is to be understood that instead of using a linear electric motor any system of traction may also be used, mechanical, hydraulic, pneumatic, magnetic, electrical or other known type capable of exerting on the mobile units in deceleration a thrust which may driYe either in the sense of motion or which is sufficient at least to balance all accidentals and contingencies of breakage which may show themselves.

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~ ~ - 21 -

Claims (36)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLU-SIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a transport apparatus of the type com-prising a series of mobile units constrained to move along a closed path having high and low speed zones, the improve-ment wherein the mobile units are permanently interconnected by link means which permits the speed of the mobile units relative to each other to change according to whether they are in a high or low speed zone, a continuous extended drive means is arranged along part of the closed path, and means are provided for engaging the mobile units with the extended drive means when they travel along the high speed zones of the closed path.

2. A transport apparatus according to claim 1, wherein said link means comprises a mechanical assembly made up of links of variable length.

3. A transport apparatus according to claim 1, wherein the extended drive means comprises at least one endless cable, conforming to a defined path and travelling at a constant high speed equal to the highest speed of the transport apparatus.

4. A transport apparatus according to claim 3, wherein the extended drive means is formed by several por-tions of cable, each being looped upon itself and being disposed in the high speed zones of the mobile units.

5. A transport apparatus according to claim 4, wherein the successive loops of the extended drive means leave free between them gaps along the path of the mobile units corresponding to station zones, which are zones of low speed or of standstill.

6. A transport apparatus according to claim 1, wherein each mobile unit is provided with connecting means for engagement with the extended drive means, said connec-tion means only being engaged in the high speed zones.

7. A transport apparatus according to claim 6, wherein power is applied simultaneously by the extended drive means to each of the mobile units located in the high speed zone.

8. A transport apparatus according to claim 1, wherein the link means is of the type having drums for winding or unwinding connecting cables extending between adjacent mobile units.

9. A transport apparatus according to claim 1, wherein the link means is an endless chain looped upon it-self, with deformable links of constant perimeter defined by an endless cable.

10. A transport apparatus according to claim 1, wherein the link means is always engaged with every mobile unit along the whole length of the closed path and deter-mines at each point the gap which separates one mobile unit from the adjoining units, the speed of the units following at each point a pre-programmed function.

11. A transport apparatus according to claim 6, wherein the means for connecting a mobile unit to the ex-tended drive means comprises friction clamps which re-spectively disengage the mobile unit concerned from the extended drive means at the entrance to a deceleration zone and re-engage the mobile unit at the exit from an acceleration zone.

12. A transport apparatus according to claim 6, wherein the means for connecting a mobile unit to the extended drive means comprises pairs of blocks articulated to and carried by the extended drive means.

13. A transport apparatus according to claim 6, comprising a fixed structure equipped with inclined ramps at least in zones where the speed of the mobile units changes and in the low speed zones, said ramps acting on elements of the group of mobile units in order to produce speed variations.

14. A transport apparatus according to claim 13, wherein the extended drive means is provided with driving members for drawing it along at a constant speed which can be regulated.

15. A transport apparatus according to claim 14, comprising a control system for regulating the tension in the link means, said system assuring an interconnection between the driving members and the drive means.

16. A transport apparatus according to claim 15, wherein the control system comprises one or several sensors of the strain taken up by the ramps of the fixed structure in the zone or zones where the tension of the bands is at a maximum.

17. A transport apparatus according to claim 16, wherein the value of the torque applied to the ramps of the fixed structure is detected by means of rolling or sliding members carried by the mobile units.

18. A transport apparatus according to claim 17, wherein a maximum tension of very low value is displayed on the control system, which applies an appropriate signal to driving members of the drive belt means in order to maintain within the said value the tension in the link means.

19. A transport apparatus according to claim 1, comprising safety means for braking or affecting emergency stops, and means for starting off, the strain and tension caused by the action of these means being almost entirely taken up by the extended drive means.

20. A transport apparatus according to claim 1 wherein said drive means comprises a single drive cable and said link means comprises a single variable link cable, each being formed in a loop, the path of the variable link cable diverging from the path of the drive cable at opposite extremities of the closed loop in order to define two zones of travel at high speed and two stationary zones at the extremities of the closed-loop path.

21. A transport apparatus according to claim 1, comprising control means for controlling the tension in the link means in a zone where the mobile units are disengaged from the extended drive means.

22. A transport apparatus according to claim 21, wherein said control means varies in a controlled manner the position of the point at which the mobile unit re-engages with the extended drive means.

23. A transport apparatus according to claim 22, wherein a servo control device is provided to control the means of varying the position of the point of re-engagement as a function of the tension in the link means detected at the level of the relevant station.

24. A transport apparatus according to claim 23, wherein means are provided for connecting the mobile units to the extended drive means, said connecting means comprising a friction clamp capable of engaging the extended drive means by closing under the action of a return spring or of disengaging the drive means by opening under the action of a control ramp, and the servo control device is adapted to control the position of the control ramp as a function of the delay of the mobile units leaving the station.

25. A transport apparatus according to claim 24, wherein the link means comprises a chain with links having drums for winding or unwinding connecting cable, and the normal seizure of the extended drive means by the clamp of each mobile unit occurs at a location fixed relative to the end of the ramps controlling the unwinding.

26. A transport apparatus according to claim 21, wherein said control means comprises means capable of causing a variation in pre-programmed speed.

27. A transport apparatus according to claim 26, wherein the link means comprises a chain with links having drums for winding and unwinding a connecting cable, and means capable of causing a variation in a pre-programmed speed are provided which act on the position of the ramps, which limit the length of the unwound cable.

28. A transport apparatus according to claim 21, wherein said control means comprises an elastic member disposed on the section of the link means which connects two adjacent mobile units.

29. A transport apparatus according to claim 28, wherein each elastic member is associated with a system of catches which allows the movement of the said member only in the zone of deceleration and in the low speed or stationary zone.

30. A transport apparatus according to claim 21, whereln each mobile unit comprises two members for con-nection with the drive means, that is a first connection member which engages the or each mobile unit to the drive means in zones of high speed, and a second connection member capable of effecting entrainment by friction with a variable degree of slip.

31. A transport apparatus according to claim 30, wherein the second connection member comprises, for each mobile unit, a pair of holding pulleys which clamp the traction cable between them, each holding pulley being comprised of two complementary half-pulleys mounted for rotation about a shaft rigidly fixed to the mobile unit, wherein the two half-pulleys are packed with friction discs, whilst the means allowing the packing to be held on each shaft is a function of the overtension in the link means.

32. A transport apparatus according to claim 1, wherein safety systems are provided such that on deceler-ating a mobile unit always exerts a tension on a cable in front of it, that is up the line, but never on a cable behind or down the line, beyond a certain pre-determined traction force, while on accelerating the mobile unit always exerts a pull on a cable behind it but never on a cable in front of it beyond a certain predetermined traction force.

33. A transport apparatus according to claim 32, wherein the safety systems consist of means for increasing the inertia of the mobile units by directly increasing their mass.

34. A transport apparatus according to claim 32, wherein the safety systems consist of systems capable of exerting on the mobile units upon deceleration a thrust directed in the sense of movement, this thrust being suf-ficient to balance at least all the causes of accidental and contingency braking which may arise, the said systems enabling the use of any suitable method of traction.

35. A transport apparatus according to claim 35, wherein the systems consist of linear electric motors having stationary coils located along said closed path, armatures therefore being located in the mobile units.

36. A transport apparatus according to claim 32, wherein the safety systems consist of means for increasing the inertia of the mobile units by utilizing the kinetic inertia connected with the rotation of rotating members of the mobile units.