PT1538344E - Locking cylinder - Google Patents

Abstract

The locking cylinder unit (20) has a spindle (35) which is axially movable relative to the cylinder (21) and fixed to a support body other than the second axial bearing, which takes the axial forces acting on the spindle. The second axial bearing has a rolling bearing movable in the direction of the longitudinal axis (29) of the cylinder, which is sprung by a spring acting in the first direction (28).

Description

1

DESCRIPTION " LOCK CYLINDER " The invention relates to a locking cylinder having the features of the generic term of patent claim 1.

A locking cylinder of this type has been known from JP 083 034 10 A. There is provided a bulky locking piston as a locking structure, through whose central inner diameter extends a rod of a ball screw spindle and which is connected as a single piece with numerous teeth erected and arranged concentrically in relation to the spindle and along the spindle. In the locking position, the teeth of the locking piston are integral with the opposing teeth of a toothed wheel, which is fixedly connected with the spindle that receives it concentrically. In this way, a type of toothed coupling is designed. The locking piston has, on its opposite side to the teeth, a hollow segment with an inner bead and the profiles of the teeth of the inner indentation extend parallel to the rotational axis of the spindle. The inner indentation is integral with an adequate outer indentation of a pinion, which is fixedly attached to a cylinder cover plate. Thus, the locking piston can be moved parallel to the rotational axis of the ball-bearing spindle, but housed in a rotation, locked about the axis of the spindle. 2

At the outer circumference of the locking piston there is provided a surrounding seal which seals a space with pressure means relative to the cylinder cover plate.

This construction of a locking unit is expensive and requires relatively much space. In order to unlock or lock the large and compact locking piston which is conditioned by the construction and hence heavy, relatively large forces are required and / or relatively long unblocking or locking times are required, which also entails a corresponding safety risk. The locking piston must be sealed at its outer perimeter with a wraparound seal which causes the respective friction forces during the displacement of the locking piston for locking or unlocking purposes, thereby limiting the efficiency of this locking cylinder. The ball screw spindle is so housed in the cylinder by a ball bearing and a sliding bearing disposed at the free end of the spindle rod, that it is impossible for the spindle to move in the longitudinal direction of the cylinder, whereas a rotation of the spindle on its longitudinal axis is possible. To this end, the free end of the spindle rod slides over an inner area of the cylinder cover plate and the ball bearing is secured with the aid of a nut fastened on an outer thread of the spindle roller spheres against a deviation transverse to the cylinder. 3

This construction is limited to applications where only relatively small loads can be lifted. On larger loads, however, wear to corrosion of the slip bearing can occur. This may cause formation and separation of metal chips or particles, which may impair the functionality of the locking aggregate until locking piston locking. This implies an unacceptable security threat. The control of the locking piston locking unit and the piston displacement control are actuated in this version by mechanically coupled steering valves so that in the raising or lowering of the load there may be undesired advancement of the piston. This implies a hardly controllable piston movement. Particularly in the case of higher piston pressures or speeds, cavitation may occur in the piston rod and piston rod, which implies a safety hazard and limits the life of the piston. The invention therefore seeks to achieve a locking cylinder, which mainly allows greater operational safety. This task is solved by the features of patent claim 1. Through these measures it is possible to displace even very large loads and / or achieve high piston speeds without causing great wear on the bearing area, ensuring safe and long-lasting operation of this type of locking cylinders. 4

Thereby, a locking cylinder, which allows greater operational safety, can be provided in a construction which does not occupy much space, in the area of the spindle housing and in the area of the locking unit.

In accordance with an advantageous variant of embodiment, it may be provided that the support structure has at its free end a bearing surface, which rests on an opposing bearing surface of the cylinder head, when the bearing structure assumes axial forces in the second which hold the spindle at a pressure and preferably transmits it to the cylinder. Advantageous support of this kind arises mainly in the case of overload or damage.

According to another example of advantageous execution, it may be provided that the support structure, in case of subjecting the spindle to pressure, is lifted from the bearing surface of the cylinder head with an operative axial force, which subjects the spindle to a pressure in the second direction and which does not reach a certain axial limit force, in the raised state the spindle is resiliently housed in the second axial bearing.

According to another example of advantageous execution, the support structure may be provided, if the spindle is subjected to a pressure in the second direction, with an axial overload force equal to or greater than the axial limit force on the surface of cylinder head, the axial forces of overload being transmitted to the cylinder or compensated therein. 5

According to another example of advantageous execution, it may be provided, in case of subjecting the spindle to the axial overload force, and, from the raised state of the bearing structure, wherein the spindle is subjected to operative axial force, the bearing structure the second axial bearing and spindle, as opposed to the spring forces exerted by the spring on the second axial bearing in the second direction, are displaced until the bearing structure abuts the bearing surface of the cylinder head, so that the axial forces which act on the spindle in the second direction, are transmitted by or supported by the support structure for the cylinder.

According to another example of advantageous execution, the support structure may be provided as a cylindrical bolt.

According to another example of advantageous execution, it can be provided that the support structure is arranged coaxially with the rotational axis of the spindle.

According to another example of advantageous execution, the second axial bearing may be provided to be incorporated in the support structure.

According to another example of advantageous execution, the second axial bearing can be provided as a needle roller.

According to another example of advantageous execution, the second axial bearing 6 may have a lower load capacity with respect to a load capacity of the first axial bearing.

According to another advantageous embodiment, the first axial bearing may form a first radial bearing with a first bearing diameter and the second axial bearing forms a second radial bearing with a second bearing diameter smaller than the first bearing diameter of the bearing first radial bearing.

According to another advantageous example of embodiment, the spring may be provided with a disc spring.

According to another example of advantageous execution, the spring may be provided with a plurality of disc springs, in the case of a package of disc springs.

According to another example of advantageous execution, it may be provided that the disk springs are housed in the support structure.

According to another example of advantageous execution, the bearing structure can be provided, the thrust bearings and the springs are arranged coaxially with the rotary axis of the spindle.

According to another example of advantageous execution, it may be provided that the locking structure is designed as a locking piston. 7

According to another example of advantageous execution, it may be provided that there are several locking structures and that the support structure, the second axial bearing and the spring are in a projection arranged at a level of projection vertically designed to the rotational axis of the spindle within a circuit which interiorly limits the locking structure relative to the rotational axis of the spindle, i.e. " between " support structures. It will be understood that the above measures can also be freely combined in the scope of feasibility in a lock cylinder of the aforementioned type so as to be able to provide a lock cylinder with the corresponding advantages combined.

Further views, features and advantages of the invention can be drawn from the following descriptive part, where we will explain in detail two preferred embodiments of the invention: Figure 1 shows a cross-sectional longitudinal section through a locking cylinder in accordance with the invention; Figure 2 shows an enlarged cross-sectional view according to Figure 1 in the area of the locking piston shown on the right-hand side; Figure 3 shows a partial cross-section of the locking cylinder along the cut line 3-3 in Figure 1 for illustration of the number and arrangement of the locking recesses; Figure 4 shows an enlarged longitudinal cross-section in the area of an alternative embodiment of a locking piston; Figure 5 shows a hydraulic circuit diagram according to a first variant embodiment of the invention; Figure 6 shows a hydraulic circuit diagram according to a second embodiment variant of the invention. The lock cylinder 20 shown in Figure 1 comprises a cylinder 21 and a piston 22 therein longitudinally housed and movable. The piston 22 is sealed relative to the inner wall of the cylinder by an annular seal 68 and can be pressurized in its cables 44, 46, which move away from one another in the direction of the longitudinal axis 29 of the cylinder 21, through a means of liquid pressure, preferably oil, to allow a movement of the piston 22, supported by the pressure medium, in a collecting direction 27, also referred to as a second direction or direction of unlocking or in an outlet direction 28, also referred to as the first direction. The piston 22 is fixedly attached to a piston rod 23 which extends coaxially from a front side 44 to the longitudinal axis of the cylinder 28. The cylinder 20 is closed on its side assigned to the free end 67 of the spindle 35, through of a cap 30 housing the piston rod 23. From its other side, the cylinder 21 is fixedly attached to a stepped protrusion 66. This is in turn closed by a cap or head 31 forming the bottom of the cylinder 53. The piston 22 forms a projection 32 which is fixedly attached to the piston rod 23. The piston 22 is designed as a hollow body and has an internal thread 34 also referred to as a piston thread. This thread engages an outer thread 36 of a spindle 35, also referred to as a spindle thread, through which the piston 22 is conveyed. The internal thread 34 of the piston 22 and the external thread 36 of the spindle 35 are preferably designed as eight-step threads fast trapezoids, which together form a thread 37, which is not self-locking.

In order to secure the locking cylinder 20, the piston rod 23 has at its free end a locking element 25 with an eye and on the opposite side of the head 31 of the cylinder 21 there is a respective locking element 26. The pressure medium can be transported through the channels 48 and 49, the two sides 44 and 46 of the piston 22, to a first working chamber 45 and to a second working chamber 33 to be able to obtain a movement of the piston 22 along the cylinder 21 in the collection direction 27 or outlet port 28. The first working chamber 45 is sealed, relative to the second working chamber 33 through the annular seal 68 of the piston 22.

In the area of the end 77, which moves away from the free end 67 of the spindle 35, it is fixedly attached to a flange-shaped flange 65. This projection has, in the area of its bottom end side of the cylinder, a part of the annular wall 79, which extends transversely or rectangularly to the rotary axis 10 of the spindle 35. This part of the wall is housed on the side facing the free end 67 of the spindle 35 through a first axial axis 120, here in the form of a first radial bearing 127 designed as a needle roller bearing 138, in a bearing step and of the cylinder boss 66 system. ball and roller bearing 137 serves to assume the axial forces on the spindle 35 in the output direction 28. In order to be able to assume also the axial forces on the spindle 35 in the collecting direction 27, opposite to the output direction 28, two measures:

In order to assume the axial operating forces on the spindle 35 during the normal service of the lock cylinder 20 in the first direction 28, a second axial bearing 121 is provided in the form of a second radial bearing 130, disposed at the end side 77 of the head spindle 35. This axial bearing 121 is also constituted as a ball and roller bearing 122 in the form of a needle roller bearing 123. It is coaxially assumed with respect to the rotational axis 43 of the spindle 35, fixedly with the bearing structure 124 attached to the spindle 35 in the form of a cylindrical bolt 125 which extends towards the bottom of the cylinder or head 31 of the cylinder 21 and is coaxially disposed relative to the rotational axis 43 of the spindle 35.

To the needle roller 123 is attached a package of disk springs 135 in the collecting direction 27, composed of several disk springs 134, 136. In the embodiment shown there are provided five disk springs 134 and 11 five disk springs 136. The disk springs 134 and 136 are always alternately arranged, preferably consecutively, so that the spring path of each disk spring 134, 136 is available for an elastic housing of the spindle 35. The disk springs 134, 136 are selected in relation to their elastic characteristics and arrangement, so that in the regular movement, when the piston 22 is moved in the collecting direction 27, the forces resulting from the dynamic transmission through the thread 37 without automatic locking are cleared, that is, compensated. of the spindle 35, so that the bearing structure 124 is always raised from the head 31 of the bottom of the cylinder 21.

But if the piston 22 is drawn in the opposite direction, ie in the outlet direction 28, a resultant axial force exerts its force on the spindle 35 in the outlet direction 28, so that the support structure 124 is always held up of the head 31, even with this movement of the piston.

Nothing else applies in the event of a stop of the piston 22 in a desired lifting position. It is then that the piston 22 is, as explained below, held " tight " by means of pressure, which is in the two working chambers 33 and 45, as well as, together with these liquid-coupled channels 49 and 48, so that even with highly static keys which are to be driven or not by the cylinder the support structure 124 is always lifted from the head 31 of the cylinder 21. In this case, the static load to be secured with the aid of the lock cylinder 20 and the axial forces transmitted to the spindle 35, essentially through piston 22 and the pressure medium exerting pressure thereon and through the neighboring walls of the cylinder.

However, if a damage occurs, such as p. ex. a leakage in the area or a rupture of a cable of the pressure medium, there may arise in the sense of collecting axial forces of overload, which will already be taken up with damage by the small bearing of the needles 123. For this second bearing of the needles 123 presents a smaller load capacity or a smaller bearing diameter relative to the bearing capacity or bearing diameter of the first needle roller bearing 138 to meet the requirements of a small construction of the lock cylinder 20 in the locking and storage area.

The disc springs 134 and 136 used meet these requirements, so that when the axial overload forces the spindle 35 to move in the collecting direction 27, at the same time that the disc springs 134, 136 are compressed to the support 124 abuts against the bearing surface 129 at its free end on the opposing bearing surface 131 of the cylinder head 31. The bearing structure 124 is then supported therein so that the axial forces of overload in action can be transmitted by the spindle 35 through the bearing structure 124 to the head 131 of the cylinder 21 without damaging the bearing of the needles 123. 13

Through the arrangement and the selected elastic characteristics of the disk springs 134, 136 a predetermined force is then predefined, corresponding to a certain limiting axial force, which when not reached the support structure 124 is lifted and when it is reached or exceeded, the spindle 35 moves together with the bearing structure 124 in the collecting direction 27 until the bearing structure 124 abuts the head 31 of the cylinder 21. The flange-shaped projection 65 is provided on the part of the wall 79 which extends transversely to the rotational axis 43 of the spindle 35, here with a total of eight locking recesses 38.1 to 38.8, which are open to the bottom of the cylinder 53 outwards. The locking recesses 38.1 to 38.8 are arranged at the same angular distance from one another in a weighted surrounding circle, so that there are always two diametral locking recesses one with respect to each other and, consequently, are arranged in a straight line containing the rotary axis 43 of the spindle 35. Each locking recess 38 has wall portions 70 which taper inwardly and serves as a housing for wall portions 72 which taper outwardly from locking bolts 40, 140. In this case, the free end 57 with conically tapering wall portions 72 of each locking bolt 40, 150 is preferably formed in a manner tuned to the locking recesses 38 in the area of their wall portions 70 which taper, so as to form a slit of passageway 71 to the pressure medium. This through slot 71 is in liquid connection with a slot 91, 14 being disposed in the area of the radial edges of both the flange-shaped projection 65 and the head 31 of the cylinder 21 opposite this side. This slit 91 is in liquid connection with a switching channel 47, which in turn can be in liquid connection with channels 48 and 49, through which the piston 22 can be subjected to pressure with pressure medium on its respective sides 44 and 46.

Figures 1 and 2 show a first embodiment of a locking bolt 40 and Figure 4 illustrates a second embodiment of a locking bolt 140. The locking bolt 40 is, unlike the locking bolt 140, designed in the area of its free end 57 transversely closed, while the locking bolt 140 is, as a perforated nozzle 90, has a through channel 54 open to its free end 57 and concentric to its longitudinal axis 74. The locking bolts 40 and 140 have an identical constitution, except for this through channel 54, with the same reference numerals referring to the same elements.

Each locking bolt 40, 140 is designed as a cylindrical bolt 125, preferably long stretched, symmetrically rotatable to its longitudinal axis 74. Each locking bolt 40, 140 has a cylindrically circular outer contour 50 and a cylindrically circular inner contour, or is constituted as a rotating hollow body. Each locking bolt 40, 140 further shows a cylindrically circular recess 92, formed by boundary wall portions and parallel to the longitudinal axis 74 of the respective locking bolt 40, 140 and open outwardly at the end 56 opposite the head 31 of the cylinder 21 Which recess 92 serves to accommodate and laterally support a spring 39 formed as a pressure spring. This is assumed in the assembled state with an elastic section 93 in the recess 92. In this case, the spring 39 abuts with one of its ends 95 on an inner surface 94 of a support step and the system 60, which extends radially in the locking bolt 40, 140. The other end 96 of the spring 39 rests on an inner surface of a respective support step and the system 76 of the head 31 of the cylinder 21.

Displaced at an axial distance from the inner surface of the support step and the system 76 and the outlet direction 28, there is provided a sealing abutment and counter-surface 98 which extends radially outwardly towards the locking bolt 40, 140, which is vertically disposed relative to the boundary wall portions of the bearing recess 75. Each locking pin 40, 140 has at its upper or spring-side end 59 an annular front edge 99, which has an annular sealing surface 97 and which points in the unlocking direction 27 of the respective locking bolt 40, 140. This annular sealing surface 97 is sealingly engaging the sealing abutment surface and counter-surface 98 also engaging the head 31 of the cylinder 21, when the respective locking bolt 40, 140 has been transported to its unlocked position after it has been subjected to pressure exertions exerted by the pressure medium in the felt of the release 27. Under effective pressure exertion a seal is provided therein so as to prevent any leakage of the pressure medium along the outer surfaces of the respective locking bolt 40, 140. In addition, the abutment surface and sealing counter-surface 96 advantageously limits the respective unlocking stroke of the unlocking bolt 40, 140.

Each locking pin 40, 140 is movably and loosely housed in the bore with cylindrical inner contour 98 or recess of the bearing 75, parallel to the rotational axis 43 of the spindle 35, and can therefore be moved from the position by means of the pressure means and against the elastic forces of the spring 39, into its unlocking position, or it can be transported again, by means of the locking means 41 indicated in figures 1, 2 and 4, in the outlet or release direction 28, in the opposite direction and after discharging the pressure in the area of its free locking end 57, from its unlocking position automatically to its locking position 41, that is, by the return elastic forces exerted by the respective spring 39 in the respective locking bolt 40, 140. The bearing recess 75 thus has an inner diameter slightly greater than the outer diameter of the locking bolt 40, 140.

Unlike the locking bolt 40 shown in Figures 1 and 2, the locking bolt 140 of Figure 4 is designed as a pierced nozzle 90 and has at its free end 57, which in the locking position 41 indicated in Figure 4 protrudes into the recess 38 is a central passageway 54. This passageway channel 54 is coaxially disposed relative to the longitudinal axis 74 of the locking bolt 140. The through channel 54 has a similarly reduced cross-section of circulation and passes, in the direction of its other end 59, to a channel part 78 which also has cylindrical wall portions and which has a larger cross-section of circulation. The channel portion 78, in turn, under formation of the abutment and abutment surface 60, into a recess 92 of the upper channel diameter 61, which is slightly larger than the outer diameter 62 of the spring 39 mentioned in the recess 92. The pressure spring at one end lies in the abutment and abutment level 60 of the locking bolt 140 and abuts the other end at the abutment and abutment level 76 of the cap or head 31 of the cylinder 21. The locking bolt 140 has at its free end 57 an active area 58 disposed vertically with respect to the longitudinal axis 74, where the liquid pressure medium can grasp to pass the locking bolt 140, from the locking position 41 shown in figure 4, to a unlocking position where it is not engaged in the locking recesses 38.1 to 38.8, i.e. it does not further block a rotation of the spindle 35 in a direction 51 or a counter-direction 52. The effective area 58 is much larger than the cross section in the free end area 57 of the locking bolt 40, 140. In this way, it enables a safe unlocking of the locking bolt 40, 140. In addition, it is possible to move the locking bolt 40, 140 , conditioned by the forces exerted by the spring 39, to its locking position 41, with a pressure relief in the locking recesses 38, is intentionally for the purpose of determining the piston 22 with its piston rod 23 in a certain position of unintentional, such as leakage or total failure of the hydraulic system. In the case of locking bolts 140, the pressure medium which is in the assigned locking recess 38 may be circularly passed through the through channel 54 of the locking bolt 140 to the channel 55 which serves the discharge channel. On the other hand, by using locking bolts 40 and as they move from their unlocking position to the locking position 41, the oil in the assigned locking recesses is pushed through the switching channel 47 and through the locking means return 160, to the feed channel 86 or to the return channel 87, depending on the position of the locking member 171 of the return circulation locking means 160 constituted as an alternating valve.

In figures 5 and 6 we can see hydraulic circuit diagrams, where particularly advantageous means and control paths are used. The switching according to the circuit diagram of figure 5 may be advantageously used for the operation and operation of a locking cylinder 20 equipped with a locking bolt 40. Of course, the switching or control elements of the circuit diagram according to figure 5, may also be advantageously used associated with the locking bolt 140 shown in figure 4. The switching according to figure 5 allows a particularly advantageous control of the locking cylinder 20 because this switching and the control means used therein allow the pressure medium to be first transported to the locking structures 42 to bring them back to their unlocking position and then transported to the first working chamber 33 or the second working chamber 45 to drive a movement of the piston 22 in the first direction 28 or second direction 27. In this way, it is possible to minimize wear on the area of the locking bolts 4 0 and in the area of the locking recesses 38 and it is prevented that the locking bolts 40 engages, especially when the connecting pressure is low.

Conversely, in the switching according to figure 6, it is provided that the working or pressure medium is conveyed to the locking structures 142 to bring them into their unlocking position, while bringing the pressure means into the first working chamber 33 or to the second working chamber 45 to drive a movement of the piston 22 in the first direction 28 or in the second direction 27.

We explain in detail certain connection elements or commands essential to the invention, which can be advantageously used when associated with both switching variants:

There are provided two lowering brake valves for fastening the designated loads of lowering braking means of the fastening of loads 150.1, 150.2, which, when the piston 22 is subjected to pressure on its first side 46 20 with the pressure medium in the first chamber 33 under a working pressure which moves the piston 22 in a first direction 28, simultaneously causes, in the second working chamber 45 on the second side 44 of the piston 22, a back pressure exerted by the pressure medium is in the second working chamber 45, which is lower than the working pressure in the first working chamber 33, so as to avoid uncontrolled advancement of the piston 22 in the first direction 28, and, on the contrary, when the piston 22 is subjected to pressure in its second side 44 with the pressure medium which is in the second working chamber 45, under the formation of a working pressure, which causes a displacement of the piston 22 in a second direction 27 opposite the first direction 28, simultaneously causes in the first working chamber 33 on the first side 466 of the piston 22 a back pressure exerted by the pressure medium which is in the first working chamber 33, which is lower than the working pressure at second working chamber 45 so as to prevent uncontrolled advancement of the piston 22 in the second direction 27 and in which the lowering braking means of the load securing 150.1, 150.2 blocks with an intentional pressure relief to be able to secure the piston 22 in a desired lifting position, a return of the pressure medium of both working chambers 33, 45, so that the piston 22 is firmly secured in the desired lifting position through the pressure medium which is in the working chambers 33, 45.

Each lowering brake valve of the load securing 150.1, 150.2 has an inlet 153.1, 153.2, 21 an outlet 154.1, 154.2 and a control port 155.1, 155.2 for the pressure medium, wherein the inlet 153.1 of the first brake valve of the load securing 150.1 is fluid connected with the first working chamber 33 and wherein the inlet 153.2 of the second lowering valve of the load securing 150.2 is liquid connected to the second working chamber 45 and wherein the outlet 154.1 of the first lowering brake valve of the load attachment 150.1 is fluidly connected to the control link 155.2 of the second lowering brake valve of the load attachment 150.2 and wherein the outlet 154.1 of the second lowering brake valve of the load fixture 150.2 is fluid-connected to the control link 155.1 of the first lowering brake valve of the load attachment 150.1 and that with the inlet 153 .1, 153.2 and the outlet 154.1, 154.2 of the respective load-securing lowering brake valve 150.1, 150.2 is correspondingly liquid-coupled with a return flow locking means 156.1, 156.2, which allows a circulation of the pressure medium of the exit valve 154.1, 154.2 to the inlet 153.1, 153.2 of the respective load-securing lowering valve 150.1, 150.2, but which in the opposite direction blocks and that optionally the outlet 154.1 of the first lowering valve of the load-securing device 150.1 and , consequently the control link 155.2 of the second lowering brake valve of the load securing 150.2 or the outlet 154.2 of the second lowering brake valve of the load securing 150.2 and consequently the control link 155.1 of the first brake valve of depressing the load attachment 150.1 are subjected to pressure of the pressure medium to achieve a displacement of the piston 22 in the first direction 28 or in the direction second sense 27 due to the respective working pressure and simultaneously forming the respective pressure back pressure on the second lowering brake valve of the load fixing 150.2 or on the first lowering brake valve of the load fixing 150.1, preferably depending on the pressure which acts on the respective control connection 155.1, 155.2.

Between the outlet 154.1 of the first lowering brake valve of the load securing 150.1 and the outlet 154.2 of the second lowering valve of the lowering of the load securing 150.2 is disposed at least one return circulation locking means 160, 161, which when the outlet 154.1 of the first lowering brake valve of the load securing 150.1 is subjected to pressure medium, a circulation of the pressure medium prevents the outlet 154.2. of the second lowering brake valve of the load securing 150.2 and the reverse, when the outlet 154.2 of the second lowering valve of the lowering of the load securing 150.2 is subjected to pressure medium, a circulation of the pressure medium prevents the outlet 154.1 from the first lowering brake valve of the load securing 150.1 and in both cases allows a supply of the pressure medium to the locking structure 42, 142 so that they can be brought into their unlocked position.

It is further envisaged that the return flow locking means 160, 161 will present a first port 164 for the pressure medium, a second port 165 for the pressure medium and an outlet 166 for the pressure medium, wherein the port the first inlet 164 of the respective return flow locking means 160, 161 is fluidly connected to the outlet 154.1 of the first lowering brake valve of the load securing 150.1 and wherein the second port 165 of the respective return flow locking means 160, 161 is fluid connected to the outlet 154.2 of the second lowering brake valve of the load securing 150.2, and wherein the first inlet 164 of the respective return flow locking means 160, 161 and the second inlet 165 of the respective return means return flow block 160, 161 are connected through a fluid channel 167, where a fluid channel 167 connected to outlet 166 of respective return flow locking means 160 is drained, 161 at a discharge point 168 so that a first portion of the channel 169 of the fluid channel 167 and a second portion of the channel 170 of the fluid channel 167 is derived from the discharge point 168.

In the switching according to figure 5 a locking element 171 is further provided for locking the first part of the channel 169 or the second part of the channel 170, wherein, in the locked state of the second channel part 170, the first portion of the channel 169 and the outlet 166 of the return circulation locking means 160 are liquid-connected so as to allow a circulation of the pressure medium of the first inlet 164 of the locking means 160 return circulation 160 to the outlet 166 of the return flow locking means 24 160, as well as from the outlet 166 of the return circulation locking means 160 to the first inlet 164 of the return circulation locking means 160, that, on the contrary, in the locking state of the second channel part 169, the second input 165 of the return circulation locking means 160, the second channel part 170 and the output 166 of the locking means return flow 160 are connected by liquid so as to allow a circulation of the pressure medium of the second inlet 165 of the return circulation locking means 160 to the outlet 166 of the return circulation locking means 160 as well as of the inlet 164 of the return flow locking means 160 to the second port 165 of the return flow locking means 160.

In the switching according to figure 5 it is further provided that the respective return flow locking means 156.1, 156.2 has a locking element 173.1, 173.2 to prevent a circulation of the pressure medium from the inlet 153.1, 153.2 to the outlet 154.1, 154.2 of the respective braking means of the lowering of the fastening of loads 150.1, 150.2, which is subjected to the spring forces of a spring 174.1, 174.2, so that an opening of the return circulation locking means 156.1, 156.2 and, consequently, pressure means of the outlet 154.1, 154.2 to the inlet 153.1, 153.2 of the respective braking means of the lowering of the load securing 150.1, 150.2 may be possible only when a limiting pressure of the pressure medium is exceeded, the value of which depends on an elastic characteristic of the respective spring 174.1, 174.2. These springs 174.1 and 174.2 are clearly visible in figure 1 at the lower ends of the two lowering brake valves of the load securing 150.1, 150.2.

Contrary to the switching according to figure 5, a locking element according to figure 6 may be provided with a locking element 172.1 for locking the first part of the channel 169 and a second locking element 172.2 for locking the second part of the channel 170, which lock the first channel portion 169 and the second channel portion 170 relative to a pressure medium circulation of the outlet 166 of the return circulation locking means 161 to the first inlet 164 of the return circulation locking means 161 and to the second input 165 of the return circulation locking means 161 and allowing a circulation of the pressure medium from the first inlet 164 of the return circulation locking means 161 to the outlet 166 of the return circulation locking means 161 and the second inlet 165 of the return circulation locking means 161 to the outlet 166 of the return circulation locking means 161.

We explain in detail the operation of the lock cylinder 20:

In the rest position of the locking cylinder 20 shown for example in figure 1, ie in the attachment of the piston 22 and the piston rod 23 to a desired lifting position, it is already hydraulically secured by the use of the lowering brake valves fixing of loads 150.1, 150.2. These are connected by liquid through the channel 48 or the channel 49 to the working spaces of the pressure medium 45 and 33 of the cylinder 21, which allow the piston 22 to be held under pressure on its side 44 facing the end of the connecting rod piston and / or its side 46 facing the bottom of the cylinder 53.

The lowering brake valves of the load securing 150.1 and 150.2 thus already allow a safety of the respective piston lifting position 22 with the piston rod 23 relative to the cylinder 21, both in the application of the lock cylinder 20 to the transmission of pressure forces, as well as for the transmission of tensile forces.

In addition to hydraulic safety with the help of the lowering brake valves of the load securing 150.1, 150.2, it is possible to provide mechanical safety of the lock cylinder 20 through the locking unit 56. This additional mechanical safety is mainly activated when a leak or a failure or similar damage to the hydraulic system. In this case, the locking bolts 40, 140 engage the locking recesses 38 so as to obtain an effective and bi-directional fixation of the spindle 35 and thus of the piston 22 in the desired lifting position. This position of engagement or locking of the cylindrical bolts 40, 140 is obtained at the moment when a pressure discharge occurs in the channels 48 or 49 and consequently also in the connecting channel 47. In this case, the respective locking pin 40.1, 40.2 , 140.1, 140.2 is pressed by the mechanical force of the pressure springs 39 against the previously rotating and flange-shaped projection 65 until the respective locking pin 27 40.1 and 40.2 or 140.1 and 140.2 engages the next possible locking recess 38 and, thereby blocking another rotational movement of the spindle 35.

We will explain in detail how the locking cylinder 20 operates, using the switching shown in figure 5:

To obtain, for example, a movement of the piston 22 and consequently of the piston rod 23 relative to the cylinder 22 in the output direction 28, the channel designated here as the feed channel 86 is subjected to pressure means, that is, it is introduced by pressure means with the aid of a pump (not shown in the figures) by the feed channel 86.

Up to a certain pressure, which depends on the elastic characteristic of the spring 174.1 of the return circulation lock 156.1, the pressure medium can not, for the time being, go to the channel 49 and consequently can not go to the work room 33, first going through the first port 164 to the first channel portion 169 of the return flow locking means 160 designed as an alternating valve, whereby its locking means 171 is displaced, under the opening of a flow path, through the first port 164. discharge point 168 to the fluid channel 167 and thence through the outlet 166 to the connecting channel 47, while closing the second portion of the channel 165, to the locking position shown on the left side of figure 5.

On the same side, the channel 88.1, which leads to the control port 155 of the second lowering valve of the load securing 150.2, is pressurized. However, the pressure of the existing pressure medium does not yet open the second lowering valve of the lowering of the load securing 150.2. The lowering braking means of the load securing 150.1 and 150.2 open against adjustable elastic forces of a respective spring 80.1 or 80.2. The respective braking means of the lowering of the fastening of loads 150.1 and 150.2 opens only from a certain pressure of the pressure medium existing in the respective control connection 155.1 or 155.2, in particular in function of the adjusted elastic forces or elastic characteristics of the springs 80.1 or 80.2. These forces or elastic characteristics are preferably adjusted so that the lowering braking means of the load fastener 150.1, 150.2 only opens when it opens the return circulation locking means 156.2 or 156.1, that is, when the respective valve of the return circulation block opens against the spring force of the respective spring 174.2 or 174.1 to cause a movement of the piston 22 in the outgoing direction 28 or in the inlet direction 27. The pressure medium therefore runs first through the connecting channel 47 to the spaces of the pressure medium in the area of the free ends 57 of the locking bolts 40 and causes them to be transported from the locking position 41 shown in the direction 27 to its unlocking position. As soon as the sealing surfaces 97 of the locking bolts 40 are in the counter-sealing surfaces 98, there is a further increase of pressure in the feed channel 86 due to more pressure means, which causes the return circulation lock 156.1 , subject to elastic pressure, open. Then the pressure medium may flow into the first working chamber 49 through the channel 49 to cause a movement of the piston 22 and hence of the piston rod 23 towards the outlet 28.

At the same time, the channel 88.1, which leads to the connection of the control 155.2 of the second brake valve of the lowering of the attachment of the load 150.2, is subjected to pressure means of a respective pressure, whereby, depending on the pressure currently in the feed channel 86, lowering brake valve of the load fixation 150.2 opens more or less to allow a circulation of the pressure medium of the second working chamber 45 through the channel 48 and through the second lowering valve of the lowering of the load attachment 150.2 in the direction of the arrow shown in Figure 5, to the return flow channel 87. The control is effected such that the back pressure regulated here by the braking means of the lowering of the load attachment 150.2, depending on the working pressure causing a movement of the piston 22 along the cylinder 21, is controlled in the feed channel 86, whereby with increasing working pressure the simultaneous back pressure is reduced, in particular, proportional inverse to the working pressure. In this way, it is always achieved in the traveling mode that the piston 22 is " tight " with a force contrary to its current direction of travel, thereby preventing uncontrolled advancement of the piston 22. 30

If desired after the piston is immobilized in a desired lifting position, the pressure in the feed channel 86 as well as the return channel 87 is preferably discharged. Consequently, the two return flow locks 156.1 and 156.2 are closed off - due to the discharge of pressure which is also effected in the control channels 88.1 and 88.2 - and the two lowering brake valves of the load securing 150.1 and 150.2, so that the pressure medium, which is in the working chambers 33 and 45, can not leave. The piston 22 is then tightened between the two pressure columns, located on its two sides 44 and 46, and is fixed in its present lifting position.

A pressure discharge in the channels 86 and 87 is also reflected correspondingly in the connecting channel 47 so that the locking bolts 40 can be transported through the spring forces of the springs 39 to which they are subjected, in the direction 28, of their position to the locking position 41 shown in the figures. In this case, the pressure medium which is in the spaces of the pressure medium ahead of the locking ends 57 of the locking bolts 40 may be moved back through the channel 47 and the alternating valve 160 here in the feed channel 86.

Depending on the rotational position at which the spindle 35 and, consequently, the locking recesses 38 are in a position of lifting attachment of the piston 22, the locking bolts 40 engage the locking recesses 38 or abut the the front surface of the annular projection 65 which contains the locking recesses 318 and which points to the head 31 of the cylinder 21, which are located between two directly adjacent locking recesses 38. In such a fastening position of this type of piston 22, it is usually not relevant if the locking bolts 40 or 140 engage the locking recesses 38. It does not apply naturally in the event of leakage or damage to the middle system pressure. The protrusion containing the locking recesses 38 still rotates somewhat until the locking bolts 40, 140 engage in the next locking recess 38. In the illustrated and described embodiments, however, only a small increase of the piston 22 in the area of millimeters and that is perfectly sufficient in terms of safety.

If it is desired to move the piston 22 and consequently the piston rod 23 from the lifting position schematically shown in figure 5 relative to the cylinder 21 in the opposite direction, that is, towards the inlet 27, the return channel 87 is subject at medium pressure. The pressure member 171 of the reciprocating valve 160 is displaced by the pressure medium flowing into the locking direction shown on the right in Figure 5 so that the pressure medium flowing into the second portion of the channel 170 through the second port 165 , may again be circulated by the discharge point 168 to the fluid channel 167 and thereafter to the connecting channel 47, the first portion of the channel 169 of the fluid channel 159 being blocked by the locking means 171. 32

After the locking bolts 140 are unlocked or brought into their unlocked position, the return flow lock 156.2 is spring loaded, so that the pressure medium can move into the working chamber 45 to displace the locking bolt 140. piston 22 in the inlet direction 27. Simultaneously, the first brake valve of the lowering of the load attachment 150.1 is again dependent on the current working pressure, now in the feed channel 87, driven through the control channel 88.2, in order to form a back pressure in the working chamber 33 below the operating pressure in the working chamber 45, so that also the movement of the piston 22 can be actuated in the inlet direction 27 without an undesired advancement thereof .

We will now describe in detail the operation of the lock cylinder 20, using the switching illustrated in figure 6:

As already mentioned, the operation and function of the braking means of the lowering of the fastening of the load 150.1, 150.2 are the same as the example of the switching according to figure 5, and can thus refer to the parts described above.

When the locking cylinder 20 is subjected to pressure medium through the feed channel 86 or the return channel 87, the connecting channel 47 is also simultaneously subjected to pressure medium. Thereby, the liquid pressure medium passes through the connecting channel 47, 33 through the slot 91 and through the circulation slot 71 to the locking recesses 38, so that the locking bolts 140 are pressed by the oil pressure, which forms there against the spring force of the respective springs 39 from the locking position 41 shown in figure 6 to the unlocking position not shown in the figures. In this case, there is at the same time a controlled leakage through the circulation channel 54 of each locking bolt 40. If, for example, the feed channel 86 is subjected to a current of the pressure medium, pressure medium can enter through of the return circulation lock 156.1 in parallel connected to the lowering brake valve of the attachment of the load 150.1 in the channel 49 and from there to the first working chamber 33 and can simultaneously reach the connecting channel 47 through the first non return valve 84 of the return flow locking means 161. The pressure medium then flows through the first inlet 164 of the return circulation locking means 161 to the first portion of the channel 169 of the fluid channel 159 and, from there via the discharge point 168 to the channel of the derived fluid 167 and then back to the connecting channel 47. In this case, the second non-return valve 85 of the circulating blocking means the return element 161 is closed, i.e. its locking element 172.2 locks the second part of the channel 170.

As soon as the locking bolts 140.1 and 140.2 have been transported while oil is being introduced into its unlocking position, the piston 22 can move, conditioned by the simultaneous pressure medium, to the output direction 28 on its side 34 46 facing the bottom of the cylinder 53. As soon as the pressure medium in the feed channel 86 is lowered, preferably to the zero value, the two return circulation locks 156.1 and 156.2 are closed, as well as the two 150.1 and 150.2 lowering of the load-securing lowering valves. The locking bolts 140 are almost simultaneously displaced by the springs 39 towards the outlet 28 so as to be able, depending on the present position of the locking recesses 38, to engage therein so that in the locking position 41 both the spindle 35 and the piston 22 are hydraulically and mechanically locked.

If it is desired that the piston 22 is again moved towards the inlet direction from the presently achieved lifting position, it may subject the return channel 87 to pressure medium, i.e. it may introduce therein pressure medium. The pressure medium may then enter the channel 48 through the non-return valve 156.2 and from that channel can reach the working chamber 45 so as to be able to subject the side 44 of the piston 42 facing towards the pressure medium to the end of the piston rod side. At the same time, a stream derived from the pressure medium through the second return valve 85 of the return flow locking means 161, into the connecting channel 47, is again fed back from the return channel 87, while the first valve return port 84 is closed. Accordingly and as already mentioned, the locking bolts 140 pass independently, that is, without an additional switching process, to their unlocking position. Then the piston 22 and, consequently, also the piston rod 23 in the inlet direction 27, a counter-pressure acting in the working chamber 33, as described associated with the switching according to figure 5, is counter-pressure which is lower than working pressure in the working chamber 15, preventing uncontrolled advancement of the piston 22 in the inlet direction 27. It is therefore a characteristic of the process according to the switching illustrated in figure 6 that the pressure medium is introduced to at least one on the sides 44 or 46 of the piston 22 and simultaneously with the locking bolt 40 for the purposes of entering and / or exiting the piston 22, the locking bolt 40 being conveyed against the spring force of the spring 39 from the locking position 41 to the unlocking position so that, finally, the spindle 35 can rotate in a direction of rotation 51 or in an opposite direction of rotation 52 with the result of the piston 22 displaced correspondingly to the direction of the direction rotation 51 or 52 in the outlet direction 28 or in the inlet direction 27. The back pressure means of the channel 55 may, depending on the pressure channels 86 or 87, return to the channel 86 or channel 87 via the non-return valve 82 or non-return valve 83.

Lisbon, 04/19/2007

Claims (17)

A locking cylinder 20 with a cylinder 21 and a piston 22, which with the aid of a liquid pressure medium can be moved parallel to the longitudinal axis 29 of the cylinder 21 and has a piston thread (34) which, under the formation of a thread (37) without automatic locking, is engaged with a spindle thread (36) of a spindle (35), which can be rotated about a rotating shaft ( 43) in parallel to the longitudinal axis (29) of the cylinder (21) and having at least one open and outwardly facing locking recess (38), wherein it is possible to engage at least one locking structure (42, 142) by means of a spring force of a spring 39 protected against rotation about the rotary axis 43 of the spindle 35 and housed parallel to the rotational axis 43 of the spindle 35 and axially displaced in a head 31) of the cylinder (21), and which with the aid of the spring force of the spring (39) can be transported to a position of b (41), where it engages the locking recess (38) of the spindle (35), in order to block a rotation of the spindle (35) about the rotational axis (43) and wherein the locking structure ) can be carried with the aid of a liquid working medium against the spring force of the spring (35) from the locking position (41) to an unlocking position, wherein the spindle (35) is rotatable about its rotational axis ( 43 to enable a movement of the piston 22 along the cylinder 21, wherein the spindle 35 is housed in at least two axial bearings 120, 121, of which a first axial bearing 120, , preferably designed as a ball and roller bearing (121), is intended to assume axial forces on the spindle (35) in a first direction (28) and wherein a second axial bearing (121) is intended to assume axial forces on the spindle (35) in a second direction (27) opposite to the first direction (28), characterized in that the spindle (35) is movably housed and axially relative to the cylinder 21 and fixedly connected with a bearing structure 124 different from the second axial bearing 121, intended to assume the axial forces on the spindle 35 in the second direction 27 and the second axial bearing (121) is equipped with a ball and roller bearing (122) movable in the direction of the longitudinal axis (29) of the cylinder (21), subject to resilient forces of a spring (126) acting in the first direction (28), so as to provide an elastic housing of the spindle (35). Locking cylinder according to claim 1, characterized in that the bearing structure (124) has at its free end (128) a bearing surface (129), which rests on an opposing bearing surface (131) of the head (31 of the cylinder 21 when the bearing structure 124 assumes axial forces acting on the spindle 35 in the second direction 27. Blocking cylinder according to claim 1 or 2, characterized in that the bearing structure (124) is raised from the bearing surface (131) of the head (31) of the cylinder (21), when the spindle (35) is subjected to an axial service force which lies below a certain limiting axial force and acts in the second direction (27) on the spindle (35), wherein in the raised state, the spindle (35) is elastically housed in the second axial bearing. A locking cylinder according to claim 3, characterized in that the bearing structure (124) abuts the bearing surface (131) of the head (31) of the cylinder (21) when the spindle (35) is held in the second direction ( 27) to an axial overload force, which is equal to or greater than the axial limit force. A locking cylinder according to claim 4, characterized in that when the spindle (35) is subjected to an axial overload force and, starting from the raised state of the bearing structure (124) in which the spindle (35) is subjected (124), the second axial bearing (121) and the spindle (35), unlike the elastic forces exerted by the spring (126) on the second axial bearing axially displaced in the second direction 27 until the bearing structure 124 abuts the bearing surface 131 of the head 31 of the cylinder 21. A locking cylinder according to claims 1 to 5, characterized in that the bearing structure (124) is designed as a cylindrical plunger (125). The locking cylinder according to one of claims 1 to 6, characterized in that the bearing structure (124) is coaxially arranged with respect to the rotary axis (43) of the spindle (35). A locking cylinder according to one of claims 1 to 7, characterized in that the second axial bearing (121) is received by the bearing structure (124). 4 A locking cylinder according to one of claims 1 to 8, characterized in that the second axial bearing (121) is designed as a needle roller (123). A locking cylinder according to any one of claims 1 to 9, characterized in that the second axial bearing (121) has a lower bearing capacity with respect to the bearing capacity of the first axial bearing (120). A locking cylinder according to one of Claims 1 to 10, characterized in that the first axial bearing (120) forms a first annular bearing (127) having a first bearing diameter (133) and the second axial bearing (121) (130) having a second support diameter (134) less than the first support diameter (133) of the first annular bearing (127). A locking cylinder according to one of claims 1 to 11, characterized in that the spring (126) is formed with a disc spring (134, 136). A locking cylinder according to claim 12, characterized in that the spring (126) consists of a plurality of disk springs (134, 136) forming a package of disk springs (135). A locking cylinder according to claim 12 or 13, characterized in that the disk spring (134, 136) or disk springs (134, 136) are or are assumed by the bearing structure (124). A locking cylinder according to one of the claims 14, characterized in that the bearing structure (124), the axial bearing (120, 121) and the spring (126) are arranged coaxially with the rotary axis (43) of the spindle (35). A locking cylinder according to one of claims 1 to 15, characterized in that the locking structure (42, 142) is formed as a locking pin (49, 140). The locking cylinder according to one of claims 1 to 16, characterized in that a plurality of locking structures (42, 142) and the bearing structure (124) are provided, the second axial bearing (121) and the spring (126) are provided. arranged in a projection at a level of vertical projection to the rotational axis of the spindle 35 within a projection circle internally delimiting the bearing structure 42, 142 relative to the rotational axis 43 of the spindle 35. Lisbon 04/19/2007