Abstract
A method for operating a telescopic device and the elongated telescopic device per se comprises a support element formed to encompass first and second telescopic element mounted so as to be telescopically slidable relative each other in a longitudinal direction; the support element comprises a support element fluid actuator assembly; the first telescopic element is arranged to encompass the second telescopic element and comprises a first fluid actuator assembly. The support element fluid actuator assembly is fixed to an interior portion of the support element and is arranged for engagement or disengagement to a first envelope surface of the first telescopic element and wherein the first fluid actuator assembly is fixed to a first interior portion of the first telescopic element and is arranged for engagement or disengagement to a second envelope surface of the second telescopic element.
Claims
1. An elongated telescopic device comprising a support element formed to partly or entirely encompass first and second telescopic elements mounted so as to be telescopically slidable relative to each other in a longitudinal direction; the support element comprises a support element fluid actuator assembly; the first telescopic element is arranged to encompass the second telescopic element and comprises a first fluid actuator assembly; characterized in that the support element fluid actuator assembly is fixed to an interior portion of the support element and is arranged for engagement or disengagement to a first envelope surface of the first telescopic element; the first fluid actuator assembly is fixed to a first interior portion of the first telescopic element and is arranged for engagement or disengagement to a second envelope surface of the second telescopic element, wherein a first and second piston body of the first fluid actuator assembly acts alternately for propelling an adjacent telescopic element, wherein the respective first and second piston body in turn is engaged with the adjacent telescopic element, wherein a first engagement and disengagement device of the first piston body comprises a first expandable hollow space and a first expandable clamping wall; and wherein the first expandable clamping wall expands in radial direction toward the envelope surface of the adjacent positioned telescopic element and clamps around the envelope surface.
2. The elongated telescopic device according to claim 1, wherein a second fluid actuator assembly is fixed to a second interior portion of the second telescoping element and is arranged for engagement or disengagement to a third envelope surface of a third telescoping element.
3. The elongated telescopic device according to claim 1, wherein the elongated telescopic device comprises a plurality of further telescoping elements mounted so as to be telescopically slidable relative to each other, each further telescoping element comprises a fluid actuator assembly arranged for engagement with an adjacent telescoping element.
4. The elongated telescopic device according to claim 1, wherein a bearing member is arranged between two adjacent telescoping elements, which bearing member comprises bronze alloy and/or tin bronze and/or lead free bronze and/or copper and/or aluminium-bronze and/or carbon graphite.
5. The elongated telescopic device according to claim 1, wherein the telescoping element exhibits a circular cross-section.
6. The elongated telescopic device according to claim 1, wherein at least one of the first fluid actuator assembly or the support element comprises a first cylinder chamber and a first piston body having a first expandable hollow space provided for fluid communication with the first cylinder chamber so as to provide engagement with an envelope surface of an inside positioned telescopic element.
7. The elongated telescopic device according to claim 6, wherein the fluid actuator assembly further comprises a second cylinder chamber, at least one of the first and second cylinder chamber is coupled to a fluid supply via a valve device.
8. The elongated telescopic device according to claim 1, wherein the second piston body of the first fluid actuator assembly comprises a static clamping unit or at least one fluid actuator unit.
9. A mobile drilling apparatus vehicle comprising an elongated telescopic device according to claim 1, wherein the elongated telescopic device is arranged as an arm member of the mobile drilling apparatus vehicle, which arm member carries a drilling and/or bolting equipment.
10. A mobile crane comprising an elongated telescopic device according to claim 1, wherein the telescopic elements constitute crane boom sections or are arranged either inside or outside the crane boom sections.
11. A method for operating a telescopic device comprising a support element and a first and second telescopic element; each of the support element and the first telescopic element comprises a first and second engagement and disengagement device; the first and second engagement and disengagement device of the support element being arranged for releasable clamping action to the first telescopic element; the first and second engagement and disengagement device of the first telescopic element being arranged for releasable clamping action to the second telescopic element; the respective first and second engagement and disengagement device being coupled to a control valve unit and a fluid supply for providing a motion of the support element and the first and second telescopic elements relative to each other in an longitudinal direction; the method comprises the steps of: pressurizing the first engagement and disengagement device with a first pressure for clamping action; pressurizing the second engagement and disengagement device with a second pressure for a release action and retraction of the second engagement and disengagement device to a start position; pressurizing the first engagement and disengagement device with a second pressure for release; pressurizing the second engagement and disengagement device with a first pressure for clamping action and propelling the second engagement and disengagement device so as to provide said motion in said longitudinal direction.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The present invention will now be described by way of examples with references to the accompanying schematic drawings, of which:
(2) FIG. 1a illustrates a section of a fluid actuator assembly of a first example of a telescopic device;
(3) FIG. 1b illustrates a pressure enforcing device of a piston body;
(4) FIG. 2 illustrates a second example of a telescopic device in an extended state;
(5) FIGS. 3a and 3b illustrate a third example of a telescopic device of a mobile crane;
(6) FIGS. 4a and 4b illustrate a fluid actuator assembly of a fourth example of a telescopic device;
(7) FIG. 5 illustrates a fifth example of a telescopic device in a front view;
(8) FIGS. 6a and 6b illustrate a sixth example of a telescopic device;
(9) FIG. 7 illustrates a section of a seventh example of a telescopic device;
(10) FIG. 8 illustrates a cross-section of an eight example of a telescopic device;
(11) FIG. 9 illustrates a fluid actuator assembly of a ninth example of a telescopic device;
(12) FIG. 10 illustrates a cross-section of a tenth example of a telescopic device;
(13) FIG. 11 illustrates an eleventh example of a telescopic device of a drilling apparatus vehicle;
(14) FIGS. 12a to 12b illustrate a portion of a twelfth example of a telescopic device;
(15) FIGS. 13a to 13d illustrate a thirteenth example of a telescopic device and extension operation;
(16) FIG. 14 illustrates a fourteenth example of a telescopic device using kinetic energy; and
(17) FIGS. 15a and 15b illustrate flowcharts showing alternative methods for operating a telescopic device.
DETAILED DESCRIPTION
(18) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, wherein for the sake of clarity and understanding of the invention some details of no importance may be deleted from the drawings.
(19) FIG. 1a shows a partial cross-sectional view of a first and second fluid actuator assembly 3, 5 of a first example of a telescopic device 1. The cross-section is taken along a centre line CL of the telescopic device 1 showing only of the cross-section of the first and second fluid actuator assemblies 3, 5 for convenience. The first fluid actuator assembly 3 is fixed to a first interior portion 7 (inner wall) of a first telescopic element 9 and is arranged at an outermost end 11 of the first telescopic element 9. The first fluid actuator assembly 3 is provided for engagement or disengagement to a first envelope surface 13 of a second telescopic element 9. The second fluid actuator assembly 5 is fixed to a second interior portion 7 (inner wall) of the second telescopic element 9 and is arranged at the outermost end of the second telescopic element 9. The second fluid actuator assembly 5 is provided for engagement or disengagement to a second envelope surface 15 of a third telescopic element 9. The first fluid actuator assembly 3 comprises a first cylinder housing 21 having a first piston 23 slidable mounted therein. The first piston 23 divides an interior of the first cylinder housing 21 into a first cylinder chamber 25 having a first fluid port 27 and a second cylinder chamber 25 having a second fluid port 27. The respective first 27 and second 27 fluid port is coupled to a fluid supply 31 via a valve device 33 for controlling the movement of the first piston 23. The first piston 23 comprises a first channel system 35 having a first cylinder chamber entrance 37 and a second cylinder chamber entrance 37 and a hollow space entrance 37. The hollow space entrance 37 is open toward a first hollow space 41 of the first piston 23, which first hollow space 41 is arranged in the first piston 23 near a first contact surface 43 of the first piston 23 contacting the first envelope surface 13 of the second telescopic element 9. The first hollow space 41 is entirely sealed and provided in a sealed manner within the first piston 23, so that no fluid is permitted to leak to the first contact surface 43 and the first envelope surface 13. The first hollow space 41 may be formed of a first and a second wall section surface 50, 50 as shown in for example FIG. 12b. The first wall section surface 50 of the first hollow space 41 and the first contact surface 43 are opposite each other and form a first homogeneous flexible wall portion 47 of the first piston 23, which homogeneous flexible wall portion 47 is provided to the first piston 23 as an integral portion. The first hollow space 41 is provided to be expandable by that the first homogeneous flexible portion 41 is flexible. The first hollow space 41 is provided for fluid communication with the first and second cylinder chamber 25, 25 via the first channel system 35 so as to provide a clamping action of the homogeneous flexible wall portion 47 to the first envelope surface 13 of the second telescopic element 9. The first fluid actuator assembly 3 further comprises a first static clamping unit 61. The first static clamping unit 61 is arranged co-linear and in tandem with the first cylinder housing 21. The first static clamping unit 61 comprises a first sleeve 63, within which is arranged a first interior space 42 that is arranged in fluid communication with the fluid supply 31. The first interior space 42 of the first static clamping unit 61 is provided expandable by that a first flexible wall 48 of the first static clamping unit 61, upon pressurizing, will expand radially inward and come into clamping contact with the first envelope surface 13 of the second telescopic element 9. The second fluid actuator assembly 5 is fixed to a second interior portion 7 (inner wall) of the second telescopic element 9 and is arranged at the outermost end 11 of the second telescopic element 9. The second fluid actuator assembly 5 is provided for engagement or disengagement to the second envelope surface 15 of the third telescopic element 9. The second fluid actuator assembly 5 comprises a second cylinder housing 21 having a second piston 23 slidable mounted therein. The second piston 23 divides the interior of the second cylinder 21 housing into a first cylinder chamber 26 having a first fluid port 28 and a second cylinder chamber 26 having a second fluid port 28. The respective first 28 and second 28 fluid port is coupled to the fluid supply 31 via the valve device 33 for controlling the movement of the second piston 23. The second piston 23 comprises a second channel system 35 having a first cylinder chamber entrance 38 and a second cylinder chamber entrance 38 and a hollow space entrance 38. The hollow space entrance 38 is open to a second hollow space 41 of the second piston 23 arranged in the second piston 23 near a second contact surface 43 of the second piston 23 contacting the second envelope surface 15 of the third telescopic element 9. The second hollow space 41 is provided in a sealed manner so that no fluid is permitted to leak to the second contact surface 43. The second hollow space 41 is formed of a first and second wall section surface corresponding with the design of the first hollow space 41. The first wall section of the second hollow space 41 and the second contact surface 43 are opposite each other and form a second flexible homogeneous wall portion 47 of the second piston 23, which second flexible homogeneous wall portion 47 is provided to the second piston 23 as an integral portion. The second hollow space 41 is provided to be expandable by that the second flexible homogeneous wall portion 47 is flexible. The second hollow space 41 is provided for fluid communication with the first 26 and the second cylinder chamber 26 via the second channel system 35 so as to provide a clamping action of the second flexible homogeneous wall portion 47 to the second envelope surface 15 of the third telescopic element 9. The second fluid actuator assembly 5 further comprises a second static clamping unit 61. The second static clamping unit 61 is arranged co-linear and in tandem with the second cylinder housing 21. The second static clamping unit 61 comprises a second sleeve 63, within which is arranged a second interior space 42 that is arranged in fluid communication with the fluid supply 31. The second interior space 42 of the second static clamping unit 61 is provided expandable by that a second flexible wall 48 of the second static clamping unit 61, upon pressurizing, will expand and come into clamping contact with the second envelope surface 15 of the third telescopic element 9. Such
(20) FIG. 1b illustrates a pressure enforcing device 400 of a first piston device 23 comprising a first piston rod engagement and disengagement device E. The piston rod engagement and disengagement device E comprises the pressure strengthening device 400, which is provided to strengthening the engagement of the first piston device 23 to the adjacent telescopic element outer envelope surface (not shown). The pressure strengthening device 400 is provided for strengthening the engagement of the first piston device 23 to said adjacent enclosed telescopic element. The pressure strengthening device 400 is arranged within the first piston device 23 and is shown in an enlarged view. The pressure strengthening device 400 comprises a movable micro piston rod 401 having a first micro pressure area mpa1 and a second micro pressure area mpa2. The first micro pressure area mpa1 being larger than the second micro pressure area mpa2, and is in fluid communication with the pressurized fluid of the pressurized cylinder chamber (e.g. reference 25 in FIG. 1a). The second micro pressure area mpa2 is arranged in communication with a pressure strengthening fluid provided in a cavity 402 for acting upon a membrane means 403 of the first piston device 23. Such pressure enforcing device 400 can be arranged also to the second piston device 23 comprising a second piston rod engagement and disengagement device E (not shown).
(21) FIG. 2 illustrates a second example of an elongated telescopic device 1 in an extended state. The elongated telescopic device 1 comprises a hollow support element 8 formed to encompass nestled first 9, second 9, third 9, fourth 9, fifth 9 and sixth 9 telescopic elements (tubes) mounted so as to be telescopically slidable relative each other in a longitudinal direction along the centre line CL. The hollow support element 8 and the telescopic elements 9-9 each comprises a fluid actuator assembly 3, 5, 5, 5, 5, 5 arranged at the outermost end 11 of the respective telescopic element 9-9. The opposite ends 12 of the elements 9-9 are provided with bearing members 71 fixedly mounted to interior portions of the telescopic elements 9-9. The respective bearing member 71 is thus arranged between two adjacent telescopic elements (for example between the telescopic element 9 and the telescopic element 9) and may comprise bronze alloy and/or tin bronze and/or lead free bronze and/or copper and/or aluminium-bronze and/or carbon graphite.
(22) FIGS. 3a and 3b illustrate a third example of a telescopic device 1 of a mobile crane 73. The telescopic device 1 comprises a plurality of telescoping elements 9 mounted so as to be telescopically slidable relative each other and each telescoping element 9 comprises a fluid actuator assembly 3 arranged for clamping to an adjacent and encompassed (nestled) telescoping element 9. In FIG. 3a is shown a state presenting almost extended telescopic elements 9. The telescopic device 1 has been lowered to a negative slope so as to make use of kinetic energy and also potential energy to extend the nestled telescopic elements 9. In FIG. 3b is shown a state where the telescoping elements 9 have made a retraction motion by means of the fluid actuator assemblies 3.
(23) FIGS. 4a and 4b illustrate a fluid actuator assembly 3 of a fourth example of a telescopic device 1. The fluid actuator assembly 3 comprises two co-operating actuators 6, 6. In the FIG. 4a is shown that the respective piston 23 of each cylinder 21 comprises annular extensions 24 (extending in the axial direction) that protrude through bores 74 of cylinder cap ends 26 of the respective cylinder 21 and surround an adjacent telescopic element 9 to be propelled. Boots 75 are arranged at both cap ends 26 for collecting fluid that leaks between the cylinder bores 74 and the envelope surface 76 of the respective annular extension 24 of the piston 23. The collected fluid is re-used and fed to the fluid supply (not shown). The leakage between the cylinder bores 74 and the envelope surfaces 76 is predetermined so as to decrease the friction between the piston 24 and the cylinder 21. The telescopic elements 9 exhibit circular cross-sections as is shown in FIG. 4b.
(24) FIG. 5 illustrates a fifth example of a telescopic device 1 in a front view. The telescopic device 1 comprises four telescopic elements 9 having circular cross-section.
(25) FIGS. 6a and 6b illustrate a sixth example of an elongated telescopic device 1. A telescopic arm 77 comprises five telescopic sections having rectangular cross-section as shown in FIG. 6b. The elongated telescopic device 1 comprises one support element 8 and six telescopic elements 9, as being shown in FIG. 6a. A respective fluid actuator assembly 3 is arranged at the respective outermost end of the telescopic elements 9. The opposite ends of the telescopic elements 9 are provided with bearing members 71. The elongated telescopic device 1 is mounted to one end of the telescopic arm 77 and to a base fundament 78 of the telescopic arm 77 for extension and retraction of the telescopic arm 77.
(26) FIG. 7 illustrates a section of a seventh example of a section of a telescopic element 9 of telescopic device 1. The cross-section is taken along a centre line CL of the telescopic device 1 showing only of the cross-section. In this example the fluid actuator assembly 3 comprises a first 62 and a second 62 hydraulic propulsion unit, each comprising a piston 23 arranged in a respective cylinder housing 21 and one hydraulic brake unit 61. The outermost end 11 of the telescopic element 9 is of somewhat greater diameter than the average diameter of the same telescopic element for encompassing the fluid actuator assembly 3. The first and second hydraulic propulsion units 62, 62 are composed of similar components as those being shown in FIG. 4a. The first and second hydraulic propulsion units 62, 62 co-operate for smooth for propulsion motion of the adjacent and encompassed (nestled) telescopic element 9 and each hydraulic propulsion unit 62, 62 alternately clamps on the envelope surface 13 of the adjacent and encompassed (nestled) telescopic element.
(27) FIG. 8 illustrates a cross-section of an eight example of a telescopic device 1. The cross-section is taken along a centre line CL of the telescopic device 1 showing only of the cross-section. In this example, the piston 23 of the respective cylinder housing 21 is encompassed entirely in the cylinder housing 23 and is slidable arranged therein. A channel system 35 is provided in respective piston 23 for offering fluid communication between the respective cylinder chamber 25 and a hollow space 41 forming a flexible inner clamping wall 47 of the piston 23.
(28) FIG. 9 illustrates a fluid actuator assembly 3 of a ninth example of a telescopic device 1. In this example the fluid actuator assembly 3 solely consists of two co-operating fluid actuators 61 provided for clamping action and for engagement or disengagement to an envelope surface 13 of a telescopic element 9 by pressurizing a rear cylinder chamber 25. The retraction of the telescopic elements 9 may be accomplished by a wire (not shown) coupled to an outer end (not shown) of the telescopic device 1 and to a winch (not shown).
(29) FIG. 10 illustrates a cross-section of a tenth example of a telescopic device 1. The telescopic device 1 comprises a plurality of telescopic elements 10, 10 (two of which are shown). The first telescopic element 10 is formed to encompass the adjacent second telescopic element 10. All telescopic elements are arranged to be telescopically slidable relative each other in a longitudinal direction (corresponding with the centre line CL). The first telescopic element 10 comprises a first fluid actuator assembly (not shown). The second telescopic element 10 is arranged slidable within the first telescopic element 10 and comprises a fluid actuator assembly 80. The fluid actuator assembly 80 is fixed to an interior portion and at the innermost end 81 of the second telescopic element 10 and is arranged for engagement or disengagement to an interior surface 82 of the first telescopic element 10. A third fluid actuator assembly (not shown) is fixed to an outer portion of a third telescopic element and is arranged for engagement or disengagement to a second interior surface (not shown) of the second telescopic element 10. A bearing member 88 is arranged between two adjacent telescoping elements 10, 10. A bearing device 88 is also arranged adjacent the fluid actuator assembly 80.
(30) FIG. 11 illustrates an eleventh example of a telescopic device 1 of a drilling apparatus vehicle 90. Rock drilling apparatus vehicles comprise boom arrangements 91 carrying drilling equipment 92. As mining equipment preferably being compact, the two telescopic devices 1 have been put into use in the drilling apparatus vehicle 90. The telescopic devices 1 serve as arms for a versatile and robust solution. The telescopic devices 1 provide that a wide range of drill/bolt lengths can be used and also enable that drilling equipment 92 of the boom arrangement 91 can be set up easily, accurately and with maximum stability and provide powerful rock drilling as each fluid actuator assembly (not shown) of respective telescopic element 9 also comprises a hydraulic static clamping unit similar to that shown in FIG. 1 in addition to a set of fluid actuator propulsion units (not shown) similar to these shown in FIG. 4a. The hydraulic static clamping unit comprises a clamping sleeve including a hollow space that is arranged to be pressurized by a fluid pressure fed by a fluid supply (not shown) of the vehicle 90 so as to expand an inner clamping wall (not shown) partly forming and sealingly limiting the hollow space for clamping on the envelope surface 13 of an adjacent telescopic element 9. Each fluid actuator propulsion unit comprises a piston including a hollow space forming a clamping membrane, which hollow space is pressurized by the fluid supply of the vehicle via a respective cylinder chamber (of a cylinder housing encompassing the piston) pressurized for propulsion of the adjacent telescopic element by means of the piston. The fluid actuator propulsion units are arranged and coupled to the fluid supply via a valve device (not shown) for operating the fluid actuator propulsion units for alternately propulsion and clamping of the adjacent encompassed (nestled) telescopic device 9.
(31) FIGS. 12a to 12b illustrate a portion of a twelfth example of a telescopic device 1. FIG. 12a shows a telescopic device 1 coupled to a fluid supply 31. Pilot and control valve devices 33 are arranged for controlling the fluid flow to the respective cylinder chamber 25. A respective piston 23 comprises a hollow space 41 for clamping action. The hollow space 41 is pressurized for clamping action and a flexible annular wall 47 portion of the piston 23 expands toward the envelope surface of the encompassed and adjacent telescopic element 9. A boot member 75 is provided at each end of the cylinder 21 for collecting fluid that leak from the cylinder chamber between the piston extension and a bore of the cylinder 21 through which the piston 23 extension protrudes. Each pair of fluid actuator assembly mounted to a separate telescopic element 9 being controlled to operate with alternately clamping for propulsion of the encompassed telescopic element. The pressurization of the hollow space 41 (and thus the clamping action) is performed by that the fluid is fed to the cylinder 21 and the respective cylinder chamber 25 for achieving a motion of the piston 23 relative the cylinder 21. A shuttle valve 95 is arranged to a channel system 35 of the piston 23 for directing the fluid flow to the hollow space 41 from the respective cylinder chamber 25. A bearing member 88 is provided at the outermost end of the respective telescopic element 9. Preferably, the proportion between the measure of inner and outer circumference of the piston body envelope surface (inner circumference/outer circumference) is larger than 0.5. FIG. 12b illustrates that the length L1 of the piston 23 sliding surface, being in slidable contact with a portion of the envelope surface (in disengaged state), is slightly less in measure than the length L2 of the hollow space 41 as seen in the longitudinal direction.
(32) FIGS. 13a to 13d illustrate a thirteenth example of a telescopic device 1 and extension operation. In this example only being shown two pairs of fluid actuator assemblies 3 mounted to respective telescopic element 9, 9. Each fluid actuator unit 62 being controlled by control valve members (not shown) to alternately provide a clamping action for propulsion of the encompassed telescopic element 9, 9. A first fluid actuator unit 62 in FIG. 13a clamps (is engaged) around the second telescopic element 9 and a second fluid actuator unit 62 is disengaged. The first piston 23 of the first fluid actuator unit 62 propels the second telescopic element 9 a first distance at the same time as a third fluid actuator unit 62 clamps and propels a third telescopic element 9 a third distance. In FIG. 13b is shown that the first piston 23 has reached its end position and the second piston 23 has been retracted to a start position. In FIG. 13c is shown that the second piston 23 is engaged with the second telescopic element 9 and propels it a second distance. At the same time a fourth fluid actuator unit 62 clamps and propels the third telescopic element 9 a fourth distance. The operation proceeds repeatedly as shown in FIG. 13d, wherein the telescopic elements are extracted.
(33) FIG. 14 illustrates a fourteenth example of a telescopic device 1 using kinetic energy. Each fluid actuator unit 62 being controlled by a control unit (not shown) controlling a control valve member (not shown) to fed pressurized fluid to the engagement and disengagement device E for alternately provide a clamping action for propulsion of the encompassed telescopic element 9 in a starting cycle.
(34) For saving energy, all the fluid actuator units are disengaged from the respective telescopic element, wherein the kinetic energy provides further extraction motion of the telescopic elements 9. The same procedure may be used for retraction.
(35) FIGS. 15a and 15b illustrate flowcharts showing alternative methods for operating a telescopic device. FIG. 15a shows a flowchart of a method according to one aspect of the invention. The method starts in a Step 101. In Step 102 there is provided a method for operating a telescopic device comprising a support element and a first and second telescopic element, wherein each of the support element and the first telescopic elements comprises a first and second engagement and disengagement device, the first and second engagement and disengagement device of the support element being arranged for releasable clamping action to the first telescopic element, the first and second engagement and disengagement device of the first telescopic element being arranged for releasable clamping action to the second telescopic element, the respective first and second engagement and disengagement device being coupled to a control valve unit and a fluid supply for providing a motion of the support element and the first and second telescopic elements relative each other in an longitudinal direction. In Step 103 the method is fulfilled and stopped. The step 102 comprises the steps of; pressurizing the first engagement and disengagement device with a first pressure for clamping action; pressurizing the second engagement and disengagement device with a second pressure for a release action and retraction of the second engagement and disengagement device to a start position; pressurizing the first engagement and disengagement device with a second pressure for release; pressurizing the second engagement and disengagement device with a first pressure for clamping action and propelling the second engagement and disengagement device so as to provide said motion in said longitudinal direction.
(36) FIG. 15b shows a flowchart of a method according to one aspect for operating a telescopic device comprising a support element and a first and second telescopic element, wherein each of the support element and the first telescopic elements comprises a first and second engagement and disengagement device, the first and second engagement and disengagement device of the support element being arranged for releasable clamping action to the first telescopic element, the first and second engagement and disengagement device of the first telescopic element being arranged for releasable clamping action to the second telescopic element, the respective first and second engagement and disengagement device being coupled to a control valve unit and a fluid supply for providing a motion of the support element and the first and second telescopic elements relative each other in an longitudinal direction. The method starts in a Step 201. In Step 202 there is provided pressurizing of the first engagement and disengagement device with a first pressure for clamping action. In Step 203 there is provided pressurizing of the second engagement and disengagement device with a second pressure for a release action and retraction of the second engagement and disengagement device to a start position. In step 204 there is provided pressurizing the first engagement and disengagement device with a second pressure for release. In step 205 there is provided pressurizing of the second engagement and disengagement device with a first pressure for clamping action and propelling the second engagement and disengagement device so as to provide said motion in said longitudinal direction. In step 206 there is provided pressurizing of the first and second engagement and disengagement device of the respective support element and the first telescopic element with a second pressure for release action of the first and second engagement and disengagement devices from the respective support element and the first telescopic element, so as to extend the telescopic device by means of kinetic energy. As an alternative step 207, there is provided lowering of the telescopic device to a negative slope so as to make use of potential energy to extend the encompassed (nestled) first and second telescopic element. In Step 208 the method is fulfilled and stopped.
(37) The elongated telescopic device comprising the telescopic elements and fluid actuator assemblies may according to different aspects be adapted to one or several of following industrial segments; construction industry, jacking systems for oil well drilling and service platforms, agricultural equipment industry, marine industry, crane manufacture industry and other industrial segments.
(38) The present invention is of course not in any way restricted to the preferred embodiments described above, but many possibilities to modifications, or combinations of the described embodiments, thereof should be apparent to a person with ordinary skill in the art without departing from the basic idea of the invention as defined in the appended claims.
(39) One aspect may involve that the telescopic device is adapted for momentary disengaging all pistons from the encompassed adjacent encompassed (nestled) telescopic element for propelling the mass of the telescopic elements using the kinetic energy of the mass (in a way reminding of a freewheel clutch). One aspect may involve that a static clamping unit may clamp (hold) rigidly to the entire circumference of the envelope surface of the telescopic element being in contact with the inner surface (clamping surface) of the static clamping unit. One aspect may involve that a clamping surface of a piston of a fluid actuator exhibits larger area than that of a piston force area of the piston. The clamping surface of the static clamping unit, seen in the axial direction, has an extension that is longer than the length of a clamping surface of a piston of a fluid actuator, seen in the axial direction. The fluid may be gas or hydraulic oil.
