IT202100009089A1 - LOCKABLE HYDRAULIC CYLINDER AND LOCKING DEVICE USABLE IN THIS CYLINDER - Google Patents

Description

LOCKABLE HYDRAULIC CYLINDER AND LOCKING DEVICE USABLE IN THIS CYLINDER

DESCRIPTION

Field of application

The present invention ? generally applicable to the technical sector of hydraulic cylinders, and has in particular a lockable double-acting hydraulic cylinder and a locking device usable in this hydraulic cylinder.

State of the art

Hydraulic cylinders are known and in particular the so-called double-acting hydraulic cylinders, i.e. cylinders in which the scroll ? controlled in both piston sliding directions.

In these cylinders the piston ? hermetically inserted into the liner to form two semi-chambers whose volume varies as the piston slides.

For this purpose, the hydraulic cylinder comprises a pair of openings, each connected to an internal half-chamber of the cylinder, so as to allow the inflow and outflow of the oil therefrom.

The movement of the cylinder, that is? the sliding of the piston, ? then controlled from the outside by means of special hydraulic circuits connected to the pair of openings to promote the entry of oil into one or the other chamber.

In particular, these hydraulic circuits include motors and pumps and a plurality of ducts and fittings to connect the latter to the cylinder. Therefore these hydraulic circuits must remain in proximity? of the cylinder resulting particularly bulky and hindering the machining. Furthermore, this solution is not applicable in some machines or systems which do not provide sufficient space.

For this purpose, ducts of relatively high length are generally used so that the overall dimensions in the vicinity? of the cylinder are minimal.

Drawback of this solution? that of presenting a response delay between the command of the hydraulic circuit pump and the movement of the piston.

In particular, if there is the need to block the stroke of the piston in the initial position, final position or in an intermediate position, ? it is necessary that both the inflow and outflow of oil from the half-chambers be prevented. Currently, the external circuits include a plurality? of so-called ?block valves? placed along the ducts. These block valves made in one block have four openings to be connected to the pumps and to the cylinder.

Therefore, these systems have particularly large dimensions, considering that each duct must have a precise minimum bending radius due to the high oil pressures inside the ducts.

Furthermore, the use of these block valves implies the use of a plurality? of fittings each of which must be assembled and closed in the correct manner as well as constantly monitored to avoid leaks. A leak could mean, for example, that a press closes involuntarily, with all the consequent risks.

Finally, these block valves must necessarily be positioned at a certain distance from the cylinder both for safety reasons (it is necessary to prevent an operator or machinery from impacting against these block valves) and for practical reasons. and dimensions, behaving cos? a high response delay between the locking action and the effective locking of the piston.

Presentation of the invention

Purpose of the present invention? that of at least partially overcoming the drawbacks noted above, providing a hydraulic cylinder with high functionality, simplicity? construction and low cost.

Another purpose of the present invention? that of providing a lockable hydraulic cylinder.

Another purpose of the present invention? that of providing a particularly safe lockable hydraulic cylinder.

Another purpose of the present invention? that of providing a lockable hydraulic cylinder of reduced dimensions.

Another purpose of the present invention? that of providing a lockable hydraulic cylinder with reduced response delays.

Another purpose of the present invention ? to make available a locking device of high functionality?, simplicity? construction and low cost.

Another purpose of the present invention? that of making available a blocking device of particularly contained dimensions.

Another purpose of the present invention? that of providing an easily assembleable blocking device.

These purposes, as well as others that will appear more? clearly hereinafter, they are achieved by a hydraulic cylinder and by a locking device in accordance with what is described, illustrated and/or claimed herein.

Brief description of the drawings

Further characteristics and advantages of the invention will become more evident in the light of the detailed description of some preferred but not exclusive embodiments of the invention, illustrated by way of non-limiting example with the aid of the attached drawings where:

FIGS. 1, 2A and 2B are respectively a front, top and side view of a hydraulic cylinder 1;

FIGS. 3, 5 and 7 are a side view in section of the hydraulic cylinder 1 in different operating stages;

FIGS. 4, 6 and 8 are an enlarged view of some details of a locking device 500 in the configurations corresponding to the cylinder configurations of respectively FIGS. 3, 5 and 7;

FIGS. 9, 10 and 11 are respectively a front, top and side view of a different embodiment of a hydraulic cylinder 1;

FIGS. 12, 13 and 14 are respectively a front, top and side view of a different embodiment of a hydraulic cylinder 1;

FIGS. 15, 16 and 17 are respectively a front, top and side view of a different embodiment of a hydraulic cylinder 1;

FIG. 18 ? a sectional side view of a different embodiment of a hydraulic cylinder 1;

FIG. 19 ? a sectional view of an embodiment of the locking device 500 which can be used in a hydraulic cylinder 1;

FIG.20 ? an exploded view of the lockout device 500;

FIG. 21 ? a partially sectioned view of a different embodiment of the locking device 500.

Detailed description of some preferred embodiments A hydraulic cylinder 1 is described with reference to the attached figures.

Essentially, cylinder 1 will be able to therefore comprising a sleeve 10 and a piston 20 inserted in the sleeve 10. The sleeve 10 and the piston 20 will then be able to slide reciprocally.

In the continuation for simplicity? will you do? reference only to the sliding of the piston 20 with respect to the sleeve 10.

The sliding of the piston 20 could be promoted by a working fluid, such as oil, so in itself? known. In particular, cylinder 1 will be able to preferably be a so-called ?double effect? cylinder, that is? can I be effective in both directions of flow.

Shirt 10 can therefore internally comprising a work chamber 30 within which it can? slide the piston 20. The working chamber 30 can? be a chamber fluidically closed, and the oil will be able? enter or exit from it only through appropriate openings and circuits as better explained below.

The piston 20 could? runs along an X axis. In particular, chamber 30 will be able to have a substantially cylindrical shape and you can develop along the same X axis.

The work chamber 30 will be able to therefore comprising a side surface 33 and a pair of bottom walls 31 and 32. known, the piston 20 potr? include a stem 21 that can? be passing through one of the back walls 31. In this case, it could? a closing element 40 coupled to the jacket 10 in a sealed manner may be provided and could cooperate with the same jacket 10 to define the working chamber 30.

The piston 20 could? be inserted hermetically into the working chamber 30 so as to divide the same into at least a first half-chamber 100 and a second half-chamber 200.

The half-chambers 100 and 200 can have variable volume.

For example, piston 20 could scroll between at least one end-of-stroke position in which the half-chamber 100 has the maximum volume and the half-chamber 200 has the minimum volume and at least one start-of-stroke position in which the half-chamber 100 has the minimum volume and the half-chamber 200 has the maximum volume.

FIGS. 3, 5 and 7 show different positions of the piston 20 in the chamber 30. In particular, FIG. 3 shows a position close to the end position, FIG. 7 shows a position close to the stroke start position, while FIG. 5 shows an intermediate position between the previous ones.

The cylinder 1 will be able comprise an opening 111 fluidly connectable with external hydraulic circuits, an opening 112 fluidly connected with the working chamber 100 and a hydraulic circuit 110 extending between the openings 111 and 112. The cylinder 1 can? further comprising an opening 211 fluidly connectable with external hydraulic circuits, an opening 212 fluidly connected with the working chamber 200 and a hydraulic circuit 210 extending between the openings 211 and 212.

Preferably, shirt 10 can include the openings 111, 211 and 112, 212. In particular, the operating chamber 30 may include the openings 112, 212, so that they allow the entry or exit of the oil from the half chambers 100, 200.

The openings 111, 211 can be accessible from the outside so that they can be fluidically connected with an external hydraulic circuit. Possibly, coupling means of a known or standard type could be provided located in correspondence with the openings 111, 211 to allow the connection of the latter with such external hydraulic circuits. Preferably, the openings 111, 211 can be placed on the same face of the jacket 10.

The openings 111, 112 could be placed in correspondence with a side wall of the jacket, i.e. a wall substantially parallel to the X axis.

The openings 112, 212 can be placed in correspondence with the bottom wall 31, 32 of the operating chamber 30. For example, if the half-chamber 100 comprises the stem 21 of the piston 20, the lateral surface 33 of the chamber 30 can understand the opening 112 which potr? be in the vicinity? of the back wall 31. On the other hand, the opposite back wall 32 of the chamber 30 will be able to understand the opening 212.

In other words, the circuits 110, 210 can be inside the jacket 10.

The cylinder 1 will be able therefore comprising means 50 for blocking the sliding of the piston 20. Thanks to these means 50, advantageously, the piston 20 will be able to? be locked in any position. For example in the position of start of stroke, end of stroke or in one or more? intermediate positions.

In general, the blocking means 50 will therefore be able to interact with the circuits 110, 210 so as to selectively allow/prevent the passage of the oil through them and therefore allow/prevent the inflow or outflow of the oil from the half-chambers 100, 200 and therefore allow or prevent (i.e. block) the sliding of the piston 20.

Conveniently, shirt 10 can include the blocking means 50. Preferably, the jacket 10 can? include a seat 15 for the locking means 50. Even more? preferably, the blocking means 50 can be placed in the seat 15 so as to remain substantially entirely contained in the seat 15 and not protrude from the jacket 15 itself.

Seat 15 will be able to then intercept one or both of the circuits 110, 210. In other words, the oil flowing between the openings 111, 211 and 112, 212 will be able to necessarily pass through the seat 15 so as to intercept the blocking means 50.

Seat 15 will be able to then define a work chamber intended to house the blocking means 50. The seat 15 will be able to therefore comprising a pair of openings 113, 114 fluidly connected to the openings 111 and 112 respectively and a pair of openings 213, 214 fluidly connected to the openings 211 and 212 respectively.

Advantageously, therefore, the hydraulic circuits 110, 210, and preferably also the blocking means 50, will be able to remain inside the jacket 10, will not be able to come out of the jacket 10 and will be able to remain substantially inaccessible from the outside.

Thanks to this feature, cylinder 1 will be able to be extremely compact, have small dimensions, and can? be particularly safe. Can you? furthermore, prevent accidental damage caused by an operator or a machine from hitting the pipes of the blocking means, causing the piston to be released with the possible serious consequences deriving therefrom.

Shirt 10 can comprise a hole 16 while the blocking means 50 can be placed in the hole 16. The blocking means 50 can possibly be inserted in the hole 16, preferably but not exclusively in a removable manner. In other words, hole 16 will be able to define the location 15.

Preferably, hole 16 will be able to be substantially cylindrical in shape.

Hole 16 could define an X axis? what can I be preferably, but not exclusively, parallel to the X axis of the chamber 30, as for example illustrated in FIG. 5. Eventually, hole 16 will be able to be configured so that the X axis? is substantially perpendicular to the X axis, as for example illustrated in FIG.18.

The blocking means 50 can be configured in different ways. Essentially, the blocking means 50 can be configured so that, once inserted in the hole 16, they intercept the oil passing through the circuits 110, 210.

The blocking means 50 could therefore include a blocking device 500. Preferably the blocking device 500 could have a substantially cylindrical shape defining an axis Y. In particular, once the locking device 500 has been inserted into the hole 16, the axes Y and X? may substantially coincide.

In particular, as for example shown schematically in FIGS. 1, 9, 12 and 15, the Y axis of the blocking device 500 will be able to be substantially parallel to the sliding axis X and spaced from it in any position, preferably inside the jacket 10.

On the other hand, as schematically illustrated in FIG. 18, the blocking device 500 will be able to be substantially orthogonal to the sliding of the piston 20. In other words, the axis Y could? be substantially perpendicular to the X axis.

The blocking device 500 and the hole 16 can be mutually sized so that the blocking device 500 is at least partially inserted in the hole 16. Preferably, most of the blocking device 500 can be internal to the hole 16. Pi? preferably, substantially all of the blocking device 500 can? be inside the hole 16. Eventually, the locking device will be able? be entirely contained in the hole 16 so as not to come out of the same hole 16.

The blocking device 500 will be able to have a length substantially equal to the length of the hole 16 or slightly greater. In this case, advantageously, can be provided for a portion d? extremity? of the block 500 easily accessible and/or maneuverable by the operator, for example to extract the block 500 from the hole 16.

Conveniently, can a closing element 570 may be provided to keep the blocking device 500 in the hole 16. For example, the closing element 570 could be? be a threaded cap screwed into the hole 16 that can? include a corresponding counter thread.

Hole 16 could then define a room of work and potr? include the openings 113, 114 and 213, 214. Preferably the hole 16 can be cylindrical and the openings 113, 114 and 213, 214 can be placed in correspondence with the side surface 161 or with the bottom wall 162 of the same.

Advantageously, the wall opposite the wall 162 will be able to be opened to allow the insertion of the locking device 500.

Conveniently, ducts 115, 215 could be provided for fluidly connecting the openings 111, 211 with the openings 113, 213. These ducts could preferably be inside the jacket 10, for example obtained in the jacket body by drilling.

Similarly, ducts 116, 216 could be provided for fluidly connecting the openings 112, 212 with the openings 114, 214. These ducts could preferably be inside the jacket 10, for example formed in the jacket body by drilling.

These openings can be observed in Fig.3 which shows the cylinder 1 in which the blocking device 500 ? disconnected from seat 15.

On the other hand, the blocking device 500 can comprise a pair of circuits 510, 520 which can preferably be fluidly independent of each other.

Conveniently, once the locking device 500 has been inserted in the seat 16, the circuit 510 will be able to be fluidically connected with the circuit 110, while the circuit 520 could? be fluidically connected with circuit 210.

Advantageously, the locking device 500 can then be configured so that when inserted into the hole 16, the openings 113, 114 and 213, 214 are in fluid communication with the circuits 510 and 520.

In particular, the blocking device 500 can therefore comprising at least a pair of openings 511, 512 and a pair of openings 521, 522. Preferably, these openings could be in correspondence with the side surface or the bottom wall of the blocking device 500. The circuit 510 could? include the openings 511, 512 while the circuit 520 could? include openings 521, 522.

Conveniently, once the locking device 500 has been inserted into the hole 16, the openings 113, 114, 213, 214 will be able to remain in fluid communication respectively with the openings 511, 512, 521, 522.

In other words, once the blocking device 500 has been inserted, the circuit 110 will be able to include the openings 111, 112, 113, 114, 511, 521, while the circuit 210 could include openings 211, 212, 213, 214, 521, 522.

The blocking device 500 will be able to be inserted hermetically into the hole 16. In this way the openings 113, 114, 213, 214 and the openings 511, 512, 521, 522 can be in correspondence or can be provided with one or more? interspaces defining fluidic connection ducts between said openings.

Preferably, the locking device 500 can be inserted in hole 16 along the X axis? of the latter with any degree of rotation with respect to the X axis?. The blocking device 500 will be able to be configured in such a way that its operation is independent of the rotation of the same with respect to the X axis?, ie? with respect to the rotation on s? itself along the Y axis.

In other words, the openings 511, 512, 521, 522 can be configured in such a way that they are fluidly connected with the openings 113, 114, 213, 214 regardless of the rotation of the locking device 500 with respect to the axis X?.

Thanks to this feature, the blocking device 500 will be able to be easily positioned in the hole 16. Furthermore, no centering means and/or means are not required to prevent the rotation of the blocking device 500 inside the hole 16.

For example, as shown in FIG. 19, the openings 511 and 521 can be fluidly connected with the openings 113 and 213 by means of a peripheral duct 513, 523 defined by a section restriction of the blocking device. The openings 512 and 522 may remain in correspondence with the opposite bottom walls of the blocking device 500. Preferably the openings 512 and 522 may be substantially coaxial with the Y axis. therefore there is a respective peripheral duct 514, 524 for placing the openings 512 and 522 in fluid communication with the openings 114 and 214.

The blocking device 500 will be able to comprise valve means 515 and 525 acting respectively on the circuit 510 and 520 to selectively allow/not allow the passage of the fluid inside the same circuits 510 and 520. In particular, the valve means 515 and 525 can be selectively opened/closed to allow /do not allow the fluid to pass inside the same circuits 510 and 520.

Pi? in detail, the circuits 510 and 520 could comprise a fluid passage opening 516, 526 interposed between the openings 511 and 512, 521 and 522. The valve means 515 and 525 could act on the respective openings 516, 526 to selectively allow do not allow fluid to pass through them.

The valve means 515, 525 can preferably be of the normally closed type.

Conveniently, can the valve means 515, 525 comprise a shutter 515? 525? and elastic means 515?? 525?? agents on the shutter 515? 525? to keep the latter closed, the cio? so that it closes the passage of the respective openings 516, 526 as described above.

Suitably, the circuits 510, 520 could include a respective working chamber 517, 527 which could house the respective shutters 515? 525?. Possibly, the work chamber 517, 527 will be able also house the elastic means 515?? 525??.

The working chamber 517, 527 of one or both circuits 510, 520 may have a development substantially coaxial to the Y axis. The working chamber 517, 527 of one or both circuits 510, 520 can? be essentially cylindrical.

According to a particular preferred but not exclusive embodiment of the invention, the shutters 515? 525? and the elastic means 515?? 525?? they can be mobile along the Y axis.

Possibly the openings 516, 526 could define the openings 511 and 521 or the openings 512 and 522. In any case, the openings 516, 526 could be fluidly connected to the openings 511, 512 and 521, 522.

Preferably, the openings 512 and 522 may be in close proximity to the of the extremities? 501, 502 of the blocking device 500, while the openings can be spaced from the ends along the Y axis. In other words, the circuits 510 and 520 will be able to develop along the Y axis.

Preferably, the valve means 515, 525 can be configured to operate in a substantially opposite way, i.e. elastic means 515??, for example a spiral spring, could force the? shutter 515? towards the? extremity? opposite 502 while the elastic means 525??, for example a spiral spring, can force the? shutter 525? towards the? extremity? opposite 501.

The circuits 510 and 520 may be fluidically independent.

Conveniently, when the valve means 515, 525 are closed, it will be possible to prevent the passage of the oil through the respective openings 516, 526 and therefore through the respective circuits 510, 520, while when the valve means 515, 525 are open it will be possible to allow the oil to pass through the respective openings 516, 526 and then through the respective circuits 510, 520.

According to a preferred but not exclusive embodiment, the valve means 515 could be configured to open when the oil enters the opening 511 to therefore allow the passage of the oil from the opening 511 to the opening 512, while they can be configured to remain closed when oil enters the opening 512 to therefore prevent the passage of oil from the opening 512 to the opening 511. Similarly, the valve means 525 can be configured to open when of the oil inlet in the opening 521 in order not to obstruct the opening 526 and therefore allow the passage of the oil from the opening 521 to the opening 522, while they can be configured to remain closed when the oil enters in the opening 522 to block the opening 526 and therefore prevent the passage of oil from the opening 522 to the opening 521.

In other words, the flow of oil will be able overcome the action of the spring 515??, 525?? in order to promote the sliding of the shutter 515?, 525? inside the chamber 517, 527 to move it away from the opening 516, 526 and therefore allow the oil to pass through it.

Although in the continuation it will be done? With reference to this configuration described above, it is however understood that the valve means 515, 525 could be configured in the opposite way, i.e. so that the flow of oil coming from the openings 512, 522 allows the opening of the valve means 515, 525 and therefore the passage of oil from the openings 512, 522 to the openings 511, 521 while they can prevent the passage of oil from the openings 511 , 521 to the openings 512, 522 without thereby departing from the scope of protection of the present invention.

To allow the oil to pass from the opening 512 and/or 522 to the opening 511 and/or 521 through the respective circuits 510 and 520, it will be possible to selectively act on the respective valve means 515, 525 so as to selectively open the same and thus allow the passage of the fluid through the opening 516, 526 from the respective opening 512, 522 to the respective opening 511, 521.

The locking device 50 can therefore comprising a slider element 530 configured to act on one or both of the valve means 515, 525 to selectively open the latter.

Conveniently, the cursor element 530 can be configured to act alternately on one or the other of the valve means 515, 525.

For example, the 530 cursor can be interposed between the valve means 515, 525 and could? therefore be movable between at least one operating position in which it interacts with the valve means 515 and at least one operating position in which it interacts with the valve means 525. be mobile in a further rest position in which it does not interact with the valve means 515 and does not interact with the valve means 525.

Conveniently, the 530 cursor can? include a protuberance 531 intended to interact with the valve means 515 and in particular with the obturator 515? to promote its sliding in the working chamber 517 and then space it from the opening 516 to allow the oil to pass therethrough. Similarly, the 530 cursor will be able to include a protuberance 532 intended to interact with the valve means 525 and in particular with the obturator 525? to promote its sliding in the working chamber 527 and then space it from the opening 526 to allow the oil to pass therethrough.

The protuberance 531, 532 will be able have a smaller section than the respective opening 516, 526 so as to allow the first to be inserted into the second without impeding the flow of oil through the respective opening 516, 526.

Advantageously, the cursor 530 can have a length such that when the same ? in the rest position, will both protuberances 531 and 532 be able to remain spaced by the shutters 515? and 525?.

In particular, in the absence of incoming oil, the action of the springs 515?? and 525?? can I promote shutter sliding 515? and 525? and consequently the sliding of the cursor 530 in an intermediate position between the operative positions, ie? in the rest position.

As for example illustrated in FIG. 19, the 530 cursor will be able to be sliding along the Y axis between the operating and rest positions described above. For example, the 530 cursor can have a substantially cylindrical main body 533 with a pair of opposite walls 534, 535, while the protuberances 531, 532 may extend from opposite sides of the cylindrical body 533, preferably from the opposite walls 534, 535.

Conveniently, the blocking device 500 can comprising a working chamber 536 fluidly connected to the opening 511 and the opening 516. Preferably, the working chamber 536 may be able to understand the?opening 511, the?shutter 515? and the wall 534 of the cursor 530. In this way, the entry of the oil into the working chamber 536 from the opening 511 will be able to promote shutter sliding 515? and the sliding of the wall 534, and therefore the opening of the valve means 515 and the sliding of the slider 530 from one operating position towards the opposite operating position, for example towards the valve means 525. In the absence of oil entering from the opening 511, the valve means 515 will close thanks to the action of the spring 515??.

Similarly, the locking device 500 can comprising a working chamber 537 fluidly connected to the opening 521 and the opening 526. Preferably, the working chamber 537 may be able to understand the?opening 521, the?shutter 525? and the wall 535 of the cursor 530. In this way, the entry of the oil into the working chamber 537 from the opening 521 will be able to promote shutter sliding 525? and the sliding of the wall 535, and therefore the opening of the valve means 525 and the sliding of the slider 530 from an operating position towards the opposite operating position, for example towards the valve means 515. In the absence of oil entering from the opening 521, the valve means 525 will close thanks to the action of the spring 525??.

Preferably, can a single working chamber 538 with the openings 511, 521, 516, 526 should be provided while the cursor 530 could be inserted into the sealed chamber 538 to divide it into the chambers 536 and 537. In this way, the sliding of the slider 530 between the operating positions can correspond the increase in the volume of one chamber and the decrease in the volume of the other and vice versa.

Conveniently, room 538 will be able to comprising a pair of opposite abutment surfaces 539 to define the stroke end of the slider 530 corresponding to an operating position and to the opposite operating position.

Advantageously, the entry of oil in the opening 511 will be able then correspond to both the scrolling of the actuator 515? (and therefore the opening of the valve means 515 to allow the passage of the oil from the opening 511 to the opening 512) that the sliding of the cursor 530 towards the valve means 525 and therefore the consequent sliding of the actuator 525? thanks to the protuberance 532 (and therefore the forced opening of the valve means 525 to allow the passage of the oil from the opening 522 to the opening 521).

Similarly, the entry of oil in the opening 521 will be able then correspond to both the scrolling of the actuator 525? (and therefore the opening of the valve means 525 to allow the passage of the oil from the opening 521 to the opening 522) that the sliding of the cursor 530 towards the valve means 515 and therefore the consequent sliding of the actuator 515? thanks to the protuberance 531 (and therefore the forced opening of the valve means 515 to allow the passage of the oil from the opening 512 to the opening 511).

If there is no flow of oil entering both openings 511, 521, the slider 530 will be in the rest position and the valve means 515, 525 will be closed. Any flow of oil from the openings 512 and 522 will not activate? the valve means 515, 525 which can remain closed and therefore will be? prevented the passage of oil through the respective openings 516, 526.

As described above, the locking device 500 can therefore be a device to allow the passage of oil from the opening 511 to the opening 512 and correspondingly from the opening 522 to the opening 521 when the opening 511 defines an inlet for the oil, or to allow the passage of the oil? oil from the opening 521 to the opening 522 and correspondingly from the opening 512 to the opening 511 when the opening 521 defines an inlet for the oil, and to prevent the passage of the oil from the opening 512 and/or 522 to the respective openings 511, 521 when the latter do not define the oil inlet.

Although it is described

This blocking device 500 could be configured inside the jacket 10 or could it? be composed of more parts inserted in the jacket 10 or can it? be preassembled and inserted in the jacket 10. In this last case, advantageously, it will be possible to replace quickly and easily.

The blocking device 500 will be able to be made in one piece, or, preferably in pi? pieces.

In particular, as for example shown in FIG. 20, the 500 stamp duty device could? be realized in a plurality? of pieces. The latter can be mutually coupled along the Y axis. Pi? in detail, the blocking device 500 can? comprising at least one element 540, one element 550 and one element 560. Preferably the elements 540, 550, 560 can all have a substantially cylindrical shape.

It is understood that each element 540, 550, 560 will be able include one or more of the pieces described above. Eventually the device 500 could? be assembled in cylinder 1, for example in hole 16 by inserting elements 550, 540, 560 or 560, 540 and 550 in sequence.

On the other hand, the 500 device could be pre-assembled. The elements 550, 540, 560 can be coupled to each other, and only subsequently inserted in the hole 16. This coupling can? be of the removable type.

Possibly, the elements 550, 540, 560 could be coupled together so as to form a single solid piece or a single piece could comprise different portions configured to define elements 550, 540, 560.

The elements 540, 550 and 560 may be removably coupled, as schematically illustrated in FIG. 19. On the other hand, according to a particular embodiment, could? a cover 590 may be envisaged. In particular, the blocking device 500 could include the cover 590 suitable for internally retaining the elements 540, 550 and 560.

In other words, the 500 device will be able to be formed by more pieces coupled together, cio? assembled, inside the jacket 10, or can it? be a single body that can be inserted into the jacket 10. In the latter case, the device 500 can be a single piece or can? be formed by more pre-assembled pieces.

In this way, the blocking device 500 will be able to be easily movable or supplied separately from cylinder 1. For example in case of maintenance.

Possibly, the blocking devices 500 could have different configurations. Conveniently, different blocking devices 500 can be inserted alternatively so that the cylinder 1 has a different behavior according to the needs.

The blocking device 500 will be able to be inserted into the jacket 10 so that it interacts with the circuits 110 and 210 as described above. Preferably, the 500 device can be inserted into hole 16 tightly.

In any case, once the block device 500 has been formed, ie? once the elements 540, 550 and 560 have been assembled, the latter can be fluidically connected so as to define the circuits 510, 520 and the valve means 515, 525 described above.

Advantageously, the locking device 500 can include an element 550 that can? include the hydraulic circuit 510 and the valve means 515, an element 560 which can include the hydraulic circuit 520 and the valve means 525 and an element 540 which could? include the sliding cursor 530.

Conveniently, these elements 540, 550 and 560 can be mutually coupled along the Y axis to define the locking device 500 of a substantially cylindrical shape.

Preferably, the elements 540, 550 and/or 560 can have a substantially cylindrical structure.

For example, the element 550 could? include an internally hollow cylindrical body 551 to define the chamber 517 which can house the spring 515?? and the shutter 515?. The body 551 will be able further comprise with a back wall 552 and an opening 553 opposite the back wall 552.

Similarly, the element 560 will be able include an internally hollow cylindrical body 561 to define the chamber 527 which could house the 525 spring?? and the shutter 525?. The body 561 will be able further comprise with a bottom wall 562 and an opening 563 opposite the bottom wall 562.

Advantageously, the 515 spring?? and the shutter 515? and the 525 spring?? and the shutter 525? can be inserted in the respective chamber 517 and 527 through the opening 553 and 563. a cap element 555 and 565 may be provided to close the respective chamber 517 and 527. Possibly the cap element 555565 could? include the respective aperture 512 and 522.

Conveniently, the elastic means 515?? and 525?? Will they be able to abut against the cap 555, 565 to force the respective shutter 515? 525? in closing against opening 516, 526.

Can the cylindrical bodies 551 and 561 comprise a respective tapered portion 551? and 561? defining the peripheral ducts 513 and 523.

The element 540 will be able comprise an internally hollow cylindrical body 541 for housing the slider 530. Preferably, the slider 530 could slide in the sealed hollow cylinder body 541.

Optionally, as schematically illustrated in FIG. 19, the pieces can be coupled axially along the axis Y. If the cover 590 is present, the elements 540, 550 and 560 can be inserted inside the cover 590. Preferably the cover 590 can? be substantially tubular so that the elements 540, 550 and 560 can be inserted inside it along the Y axis.

Once the elements 540550 and 560 have been inserted in the cover 590, they can be coupled ?package? by means of a cap so in s? known so as to assemble the locking device 500.

Once assembled, the 500 locking device will be able to then define a unit piece. could for example be marketed separately from the liner 10 and piston 20.

The locking device 500 described above can then be inserted into the jacket 10 so that the circuit 110 includes the circuit 510 and so that the circuit 210 includes the circuit 520. In this way, the action of the valve means 515, 525 on the circuits 510 and 520 to allow/prevent the passage of?oil through the same potr? correspondingly allow/prevent the passage of oil through circuits 110, 210.

The sliding of the piston 20 could therefore correspond to the volume variation of the half-chambers 100 and 200 and therefore to the passage of the oil through the circuits 110, 210. When is the passage? allowed, the half-chambers 100 and 200 will be able to vary their volume and therefore the piston 20 will be able to scroll, while when the passage ? prevented the piston can not? slide.

In particular, as better explained below, since? the openings 512 and 522 can be connected to the semi-chambers 100 and 200, the outflow of the oil from the latter without the introduction of oil into the openings 511 or 521 (and therefore 111 and 211) can be prevented, blocking cos? the sliding of the piston 20 in both directions.

In FIG. 3 and 4 ? shown a configuration of the cylinder 1 in which the piston 20 ? moving from the stroke end position to the stroke start position and correspondingly the locking device 500 ? in an operational configuration (FIG.4). In this case, the oil enters through the opening 211 and then through the opening 521 promoting rightward sliding of the actuator 525? and acting on wall 535 to promote sliding of cursor 530 to the left. The protuberance 531 of the latter could? to act against the shutter 515. In this way, the oil will flow? from the opening 521 to the opening 522 and then through the opening 212 into the semi-chamber 200. At the same time, the oil will be able to? flow from the half-chamber 100 through the opening 112 and then enter the chamber 517 through the opening 512, pass through the opening 516 kept open by the cursor and exit from the opening 511 and then from the opening 111.

In FIG. 7 and 8 ? shown a configuration of the cylinder 1 in which the piston 20 ? moving from the stroke start position to the stroke end position and correspondingly the locking device 500 ? in a different operating configuration (FIG. 7). In this case, the oil enters through the opening 111 and then through the opening 511 promoting the sliding of the actuator 515 to the left? and acting on wall 534 to promote sliding of cursor 530 to the right. The protuberance 532 of the latter can? to act against the shutter 525. In this way, the oil will flow? from the opening 511 to the opening 512 and then through the opening 112 into the semi-chamber 100. At the same time, the oil will be able to? flow from the half-chamber 200 through the opening 212 and then enter the chamber 527 through the opening 522, pass through the opening 526 kept open by the slider 530 and exit from the opening 521 and then from the opening 211.

In FIG. 5 and 6 ? shown a configuration of the cylinder 1 in which the piston 20 ? blocked. Indeed, when there is? flow of oil into the openings 111 or 211, does the locking device ? in the rest configuration in which it does not allow the passage of oil from the openings 512 and 522 to the openings 511 and 521 and therefore does not allow the oil to escape from the half chambers 100 and 200. The same configuration? illustrated in FIG. 18 in which the X axis? ? perpendicular to the sliding axis X of the piston 20.

Although not illustrated, it is understood that what is described above is equally valid regardless of the position of the hole 16 and therefore of the device 500 inside the jacket 10.

Depending on the position of hole 16, the modalities may vary? fastening of the device 500 to the jacket 10. The configurations of the circuits 110, 210 may possibly vary, for example the ducts 115, 215 and 116, 216 may have different length and path and/or the openings 111, 211 and 112, 212 may have different positions, without thereby departing from the scope of protection of the present invention.

From what has been described above, it is clear that the invention achieves the intended aims.

The invention? susceptible to numerous modifications and variations, all of which are within the scope of the inventive concept expressed in the attached claims. All the details can be replaced by other technically equivalent elements, and the materials can be different according to requirements, without departing from the scope of the invention.

Even if the? Invention? been described with particular reference to the accompanying figures, the reference numbers used in the description and in the claims are used to improve understanding of the invention and do not constitute any limitation to the claimed scope of protection.

Claims (10)

1. A double-acting hydraulic cylinder connectable with supply and discharge means of a working fluid, comprising: - a jacket (10) internally comprising a working chamber (30) having a longitudinal extension defining an axis (X); - a piston (20) hermetically inserted in said jacket (10) to divide said working chamber (30) into at least one first and second semi-chamber (100, 200) with variable volume; in which said piston (20) and said sleeve (10) are mutually sliding along said axis (X) between at least one first working position in which said first half-chamber (100) has a maximum volume and said second half-chamber (200) has a minimum volume and at least one second working position in which said first half-chamber (100) has minimum volume and said second half-chamber (200) has maximum volume, wherein the cylinder further includes means (50) for blocking the reciprocal sliding of said piston (20) and said liner (10). 2. Hydraulic cylinder in accordance with the preceding claim, wherein said liner (10) comprising a first and a second circuit (110, 210) fluidically independent of each other comprising a respective first opening (111, 211) which can be fluidically connected with the supply/exhaust of the working fluid and a second opening (112, 212) fluidically connected with respectively said at least one first (100) and said at least one second (200) half-chamber; wherein upon mutual sliding of said piston (20) and said liner (10) from said first to said second working position, the working fluid enters said second half-chamber (200) through said second circuit (210) and the working fluid in said first half-chamber (100) comes out of the same through said first circuit (110), and in which upon reciprocal sliding of said piston (20) and said liner (10) from said second to said first position working fluid enters said first half-chamber (100) through said first circuit (110) and the working fluid in said second half-chamber (200) leaves it through said second circuit (210); wherein said blocking means (50) act on said first and second circuits (110, 210) to selectively prevent the passage of the working fluid therethrough so as to block the inlet and/or outlet of the working fluid in /from said first and second half-chamber (100, 200). 3. Hydraulic cylinder according to claim 1 or 2, wherein said liner (10) includes said locking means (50). 4. Hydraulic cylinder in accordance with claim 3, wherein said liner (10) includes a seat (15) for said locking means (50), the latter and said seat (15) being mutually configured so that said locking means locking device (50) are partially or totally inside said jacket (10). 5. Hydraulic cylinder in accordance with the preceding claim, wherein said liner (10) includes a hole (16), said locking means (50) being removably insertable in said hole (16), the latter defining said seat (15 ). 6. Hydraulic cylinder in accordance with any one of the preceding claims, wherein said locking means (50) include or consist of a locking device (500). 7. Hydraulic cylinder in accordance with claims 5 and 6, wherein said hole (16) and said blocking device (500) are mutually configured so that the second is inserted hermetically into the first. 8. Hydraulic cylinder according to claim 6 or 7, wherein said locking device (500) includes a third and fourth hydraulic circuit (510, 520), said locking device (500) and said working chamber (10) being mutually configured in such a way that once the first (500) is inserted into the second (10) said first circuit (110) includes said third hydraulic circuit (510) and said second circuit (210) includes said fourth hydraulic circuit (520), said locking device (500) comprising first and second valve means (515, 525) acting on said third and fourth hydraulic circuits (510, 520) to selectively allow/prevent the passage of the working fluid through them. 9. Locking device usable in a double-acting hydraulic cylinder (1) in accordance with any one of the preceding claims, the device comprising: - a first element (550) which includes a third hydraulic circuit (510) and first valve means (515) acting thereon which can be selectively opened/closed to allow/not allow the passage of the fluid through said third circuit (510); - a second element (560) which includes a fourth hydraulic circuit (520) and second valve means (525) acting thereon which can be selectively opened/closed to allow/not allow the passage of the fluid through said fourth circuit (520); - a third element (540) comprising a slider (530) sliding between a first operating position in which it interacts with one of said first and second valve means (515, 525) to open the latter, a second operating position in which it interacts with the another between said first and second valve means (515, 525) for opening the latter, and at least one rest position in which it does not interact with said first and second valve means (515, 525), said first and second valve means (515 , 525) being normally closed. 10. Locking device according to the preceding claim, wherein said first, second and third elements (550, 560, 540) are separate pieces coupled to each other or mating along an axis (Y) to define the locking device (500) .