CA1153723A - Improvement to an hydraulic system used to move bucket conveyors - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

This invention concerns improvements to an hydraulic system used to move bucket conveyors, whereby the bucket conveyors are loaders with scoops and with at least one run substantially parallel to the ground and swivelling around a substantially vertical axis, and whereby the swivelling is governed as regards its manner and strength by the hydraulic group, and whereby the hydraulic system is of any desired type; the improvements comprise in cooperation, a motor, which is supported in a revolving manner on the axle of rotation of one pulley and has its movement defined by at least one limiting protrusion positioned to cooperate in elastic suspension with at least one substantially unmoving limiting arm; at least one transmission means is connected to and governed by the limiting protrusion of the elastic suspension and itself governing at least one regulating valve in the hydraulic system. Bucket conveyors which embody one or more of these improvements are also an object of this invention.

Description

~5;37'23 This invention concerns improvements -to an hydraulic system used to move bucket conveyors.
More particularly, this invention concerns improvements to an hydraulie system which is fitted to bucket conveyors and serves to generate in the bucket conveyor a thrust in the direction and strength desired so that the bucket conveyor can work at the base of the heap of aggregate and can withdraw the aggregate there from in coordinated cooperation with the catenary of buckets.
This invention also concerns an hydraulic system on bucket conveyors and the bucket eonveyors to which this hydraulic system is fitted.
The bucket conveyor is a loader with scoops having at least one run parallel to the ground, and swivelling around a suhstantially vertical axis.
Bucket conveyors are in themselves already known.
Hydraulic systems are also known which serve to create the required thrust of the bucket conveyor towards the heap of aggregate so that the bucket can load the desired quantity of aggregate; these hydraulie systemshave been developed preferentially by using movable rotating partition walls but, as is known, ean also be realized with a plurality of jacks or pistons in one or more cylinders. When the operator in charge of the bucket conveyor begins the work of loading a ~ ~.

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bucket conveyor, he regu].a-tes the pressure or thrus~ of the loader towards the heap of aggregate to be loaded since this adjustment is governed ~y the crumbling or cohesive nature of the aggregate.
The bucket conveyor then swivels sideways in relation to the material being removed until the whole heap is exausted or until it has loaded the quantity which is required or has been decided or can be decided.
Duriny loading, the bucket conveyor always withdraws from the heap the same quantity, depending on the thrust as regulated, so that, for instance, the buckets will be two-thirds of four-fifths or ten-tenths filled or else filled to another value chosen for normal filling.
This constant filling value is ohtained when the heap of aggregate always has the same compact or crumbling or cohesive nature. If, however, the aggregate ln a given part of the heap is more cohesive, then the buckets ga-ther less ma-terial since the thrust of known hydraulic systems always stays constant.
Furthermore, when there is a very big landslide from the heap, the buckets tend to be buried therein at least during the time needed for them to displace them-selves to one side owing to the effect of the opposing thrust which the buckets generate through their desired shape.

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The invention eliminates these shor-tcomings.
Accordiny to the invention, the motor which activates the motive or tugging pulley (or pulleys) that serves to set the catenary of buckets in motion is substan-tially suspended in an elastic manner from at least onestationary limiting arm, one or more springs or equivalent elastic means being interposed between the motor and the limiting arm.
An intermediate element which rests against the springs and is solidly fixed to the motor keeps the motor suspended in elastic equilibrium; it is also connected to a transmission means, which is connected to and controls a regulating valve. The regulating valve serves to regulate the flow (as regards pressure and/or quantity) of the oil into the thrust chamber.
Advantageously, two elastic suspension groups are envisaged, one to the right and the other to the left of the motor; in this way it is possible to provide two transmission and control means, which govern two regulating valves located in the hydraulic system; one of these valves will control a swivelling movement in one direction, and the other a swivelling movement in the other direction.
The invention makes use of the swinging movement which the motor carries out around the axle of the pulleys transmitting motion, dependiny on the ,~

effort which the motor exerts. In fact the motor pulls or slackens the thrust on the elastic suspension and thereby transmits a proportioned impulse to the trans-mission means, and the latter in their turn open or partially open or govern to a greater or lesser e~tent the regulating valve and, therewith, the bore for passage of the fluid.
The invention, therefore, pertains to impro-vements to an hydraulic system for bucket conveyors which are loaders with scoops and with at least one run substantially parallel to ground level and swivelling around a substantially vertical axis, whereby the swivelling is controlled as regards direction, manner and strength by the hydraulic system, which can be of any desired type, said invention being characterized by comprising in reciprocal coordination and cooperation:
- the motor, which is supported so as to be ab~e to revolve on the axle of rotation of one pulley and has its movement defined by at least one limiting protrusion positioned to cooperate in elastic suspension with at least one substantially stationary limiting arm, - at least one transmission means connected to and controlled by the protrusion of the elastic suspension and itself controlling at least one regulating valve located in the hydraulic system, - at least one regulating valve in thé hydraulic system and connected to and controlled by at least the trans-mission mean6.
. Another object of this invention is an hydraulic system on.bucket conveyors, whereby the bucket conveyors are loaders with scoops and with at least one run substantially parallel to the ground and swivelling around a substantiall~ vertical axis, whereby the swivelling is controlled as regards direction, manner and strength by the hydraulic system, which can be of any desired type, said hydraulic system being characterized by embodying the improvements of this invention.
A further object of this invention is a bucket conveyor that embodies the improvements of this invention.
With the help of the attached drawings, which are given as non-restrictive examples, a preferential lay-out of the invention will be described.
In the drawings:
Figure 1 gives a side view of a bucket conveyor of a type able to swivel so as to load.
Figure la is ~lenlarged si.de view of a portion of Fig~l Figure 2 shows in a diagrammatic manner an enlarged view of the proposed improvement.
Figure 3 gives a diagram of a hydraulic system embodying ~aid improvement in accordance with two variants.
With reference to the Figures: 10 is genexally the swivelling loader or bucket conveyor 11 lL~53~7~3 is the substantially vertical swivelling axis around which the bucket conveyor swivels owing to the thrust which the hydraulic system 20 generates: 12 is the ground level on which is deposited the heap of aggreyate 25 a~ainst the base of which the buckets 17 work and eat their way during that run of their path which is substantially parallel to the ground 12; at the same time the buckets cause bigger or smaller landslides in the heap and are thus able to gather the aggregate to the extent wished: 13 is the tugging motor pulley or pulleys for the catenary of buckets; pulley 13 can rotate on axle 46, which in the present embodiment also acts as a swinging support for the motor 14 which is connected, in this instance, to the pulley 13 by means of a gear wheel, and has flanged connecting means 47i the motor 14 is fed by an outside source, which is not shown here and is of a known type: 15 is the dixection of forward movement of the catenary of buckets 16-17:
16 is the ring, or rings, which connects, positions, pulls and supports the buckets 17: 17 are buckets of a known type and have a front loading mouth and an upper discharge opening substantially at right angles to the front mouth and substantially parallel to the catenary 16: 18 .is the a~le of rotation of the front lower transmission pulleys 21: 19 is the frame that serves to support the pulleys 13 and 21 and also a rear pulley, ..~

when embodied, which has not been shown in this example:
20 is the hydraulic system, being of a known type, and is connected on one side to the supporting frame 26-126 and has, on the other side, its axis 45 connected by means of the arm 27 to at least one limiting face 28 located on the frame 19: 21 is the front lower trans-mission pulley or pulleys: 22 is the run of the catena-ry substantially parallel to the ground: 23 is the rising run of the catenary: 24 is the run of the path of the catenary wherein the buckets 17 discharge the aggregate they have gathered: 25 is the heap of aggregate deposited on the ground 12, and its base is eaten away by the buckets 17 in the run 22: 26-126 is a supporting frame of any desired type, such as a trestle, legs with arms on which silos are Eitted, etc., and serves to support the frame 19 swivelling around the axis 11: 27 is the arm connecting the axis of the hydraulic system 20 and the unmoving face 28 located on the frame 19: 29 is the motor to activate the pump 31 of the hydraulic system 20 and is fed by an outside source, which is not shown in this example: 30 are the ducts feeding oil to keep the hydraulic circuit always charged: 31 is the feeder pump which, depending on the direction of the thrust to be applied to the bucket conveyor, can rotate clockwise or anti~clockwise: 32 and 132 are respectively the supplying or return ducts

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when pressure is exer-ted in -the portion 35 of the cham-ber, whereas their functions are inverted when pressure is exerted in portion 37 of the chamber: 33-133 are two valves that serve to regulate the maximum pressure in the delivery circuit and act independently during the regulating and are also cut out independently: 34-134 are two valves to regulate the flow: 35 and 37 are two half-chambers separated by a movable rotating partition wall 36; the thrust pressure is exerted in one of the half-chambers: 36 is the movable rotating partition wall, being solidly fixed to -the shaft 45, around the axis of which it rotates, and in -the example shown it receives the thrust of the hal~-chamber 35:
38 is the return-flow valve, which only works in the duct 32-132 when the duct is used for the return flow, whereas the valve remains closed in the duct 32~132 when the latter is used as a delivery line: 39 is the container to govern the oil level and comprises a lid 139 with a level-control stick and a filter 239: 40 is a small piston operated b~ the pressure in the half-chamber 35 and 37 and independently puts the half-chamber not under pressure (37 in this example) into communication with the container 39: 41-141 are the discharge ducts and receive oil under pressure from the chamber to which they are connected, and convey it to press against the corresponding small plston 142-42:

o3~3 g 42-142 are small pistons to regulate thrust and over-loading and are resisted in an elastic manner by the springs 49 and 149, which can be regulated mechanically by means of ~8-148, and are resisted in a hydraulic manner by the ducts 44-144, which have a small section and allow the oil present behind the small piston 42-142 to flow at a given time when there is a thrust greater than that realized by the springs 49-149, as can be seen in Fig. 2: 43-143 are discharge duc-ts which are left clear by the small pistons 42-142 when the latter retreat backwards: 47 are flanged connec-t-ing means which have at least one protrusion 50 but which, according to the invention, are envisaged with two protrusions, one on each side; as an example, the protrusion has solidly fixed toitself an axially non-deformable or substantially non-deformable cable 53, and its movement is resisted by at least one spring 52-152 and by at least one spring on each side of it;
where wished, the springs can be adjustable: 53 is the connecting cable that transmits angular displacement to the motor, the angular displacement being resisted by the spring 52, depending on the effort which pulley 13 has to undergo so as to drag the catenary 16-17 forwards: the suspension axle 46 rotates: 54 is the outside sheath: 55 is a plunger that is solidly fixed on one side to the cable 53, whereas on the other side ~ ~, ; 3 7 2 .3 it resists the spring 49-149 (in the example shown in Fig. 2): 56 is the regulating elemen-t which, by pressing against the sheath 54, serves to adjust the tension of the cable 53 and therefore performs a func-tion like the one carried out on bicycles with cablebrakes.
Fig. 3 shows two variants of the solution of FigO 2, and the improvements are envisaged respectively as being applied to oneof the pressure-regulating valve~ (33 in the example) and to one of the flow-regulating valves (34 in the example).
If one or the other of the variants of Fig. 3 should be embodied, it i5 clear that the corresponding valves will be involved.
According to the invention, on the plate 47, which can be an integral part of one of the components of the motor~pulley group, two protrusions 50 are visualised, one on each side, so as to enable two cables 53 to be fitted and, therefore, so as to be able to control both the two circuits of the hydraulic system so that the reversing of the working of the hydraulic system may find the adjustment already ready and operating.
According to another varian-t, instead of the regulator 56, an auxiliary spring may be envisaged as being between the plunger 55 and the regulating screws 7~

48-148.
The operation of the invention will now be described, bearing in mind that the functioning o~ the bucket conveyor 10 and of the hydraulic system as such is already known and is therefore overlooked here as regards their overall form.
~ s e~amples, two possible cases are described:
namely a first case where the motor is subjected to a moderate effort owing to the presence of rather cohesive material, and the other case where the motor has to undergo a considerable effort owing to the occurrence of a landslide of a noteworthy size of aggregate.
The example of the method of working is given with reference to Fig. 2 but could be easily transposed by a technician in the case of variants.
In the first of the two foregoing cases, as the buckets 17 are less full, the motor 14 labours less and presses more on the spring 152 and the~efore on the spring 49-149, which thrusts against -the small piston 42-142, which in its turn exerts a greater resistance to the flow of oil to the empty half-chamber of the hydraulic s~stem. The outcome of this is -that a greater thrust must develop in the half-chamber under pressure before the small piston 42-142 retreats, and this greater thrust is transmitted to the arm and enables the catenary 16-17 in its run 22 to press more heavily towards the ~.

heap 25 and thereby enables the buckets to be filled to a greater extent, thus restoring the desired equilibrium of usage.
In the second of the two cases the buckets 17 are overloaded, as said earlier, owing to a heavy land-slide. Under such conditions the motor labours more heavily, and this causes the protrusion 50 to compress the spring S2. In this way the protrusion S0 pulls the cable 53, which in its turn releases the spring ~9-149.
This spring lessens the thrust against the small piston 42-142, thus enabling the latter to open the way more easily for the pressure of the oil, which can now be discharged into the half-chamber 37, as shown in the example.
By reducing -the pressure in the half-chamber 35, the thrust of the bucket conveyor towards the heap of aygreyate .is reduced; the material of the landslide cooperating in a known manner with the particular shape of the buckets repels the arm and, as a result, the buckets gather a smaller load until the desired equilibrium is restoredO
There has been described some preferential variants here, but others are possible for a technician in this field. Thus the proportions and sizes can be varied and parts can be added or integrated; the hydrau-lic system shown can be replaced with another one that 2~

performs the same function, for instance, with opposed cylinders; it is possible to replace the metal cable with an electric transducer or with a hydraulic duct;
both the regulating valves could be governed by one single transmission means; the transmission means could be adjusted independently, and so on. These and other variants are all possible for a technician ln this field w.ithout departing thereby from -the scope of the idea of the solution.

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Claims (9)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Improvements to an hydraulic system used to move bucket conveyors mounted for rotation about pulleys, said bucket conveyors being loaders with scoops and with at least one run substantially parallel to ground level and swivelling around a substantially vertical axis, said swivelling being governed by said hydraulic system, said improvements being characterized by comprising, in reciprocal coordination and cooperation:
- a motor supported in a revolving manner on the axle of rotation of one of said pulleys and having its movement defined by at least one limiting protrusion positioned to cooperate in elastic suspension with at least one substantially unmoving limiting arm, - at least one transmission means connected to and governed by said protrusion of said elastic suspension, - and at least one regulating valve in said hydraulic system and connected to and governed by at least said transmission means.

2. Improvements to an hydraulic system as defined in Claim 1, characterized in that one valve to regulate pressure is located at least in a delivery circuit of said system.

3. Improvements to an hydraulic system as defined in Claim 2, characterized in that said regulat-ing valve and a valve to govern flow are located at least in said delivery circuit.

4. Improvements to an hydraulic system as defined in Claim 2, characterized in that said regulat-ing valve and a valve to govern thrust and overloading are located at least in said delivery circuit.

5. Improvements to an hydraulic system as defined in Claim 1, characterized in that said regulat-ing valve is regulated independently.

6. Improvements to an hydraulic system as defined in Claim 1, characterized in that said trans-mission means is regulated independently.

7. Improvements to an hydraulic system as defined in Claim 1, characterized in that the elastic suspension located between the limiting protrusion and the substantially unmoving limiting arm is regulated independently.

8. An hydraulic system for bucket conveyors, embodying the improvements defined in Claim 1.

9. A bucket conveyor having the control of its swivelling realized with a hydraulic system embody-ing the improvements of Claim 1.