EP1710449A1 - Single acting locking cylinder - Google Patents

Abstract

The shutter cylinder (20) includes a piston (22) that moves inside a cylinder unit (21), and a mechanically lockable spindle (35) that rotates inside the cylinder unit. Shutter units (42.1,42.2) are used for moving the piston and rotating the spindle in the cylinder unit using the action of a spring (39). Each shutter unit has a pawl mechanism (54) provided for the mechanical blocking the rotation of the spindle with respect to the rotation axis (43) to enable the spindle to rotate in opposing directions.

Description

The invention relates to a locking cylinder according to the preamble of claim 1.

Such locking cylinders are the subject of four not yet published German patent applications of the protected rights holder, under the official file number 103 56 597.3 . 103 56 598.1 . 13 56 596.5 such as 10 2004 022 203.7 are guided. The present patent is a further development of the above-mentioned objects of the application, so that for the sake of simplicity and to avoid repetition of the content of these four patent applications is taken in full at this point.

In certain cases of use of mechanically lockable locking cylinders, it may be necessary for the piston to be moved relative to the cylinder in the retraction direction or in the extension direction by external forces when the spindle is locked. For example, it may be desirable that in a locking only to pressure, ie in a mechanical locking of the piston relative to the cylinder in the retraction, yet the piston relative to the cylinder can be pulled out in the extension or pulled out with. This is not possible or not without a significant operational risk in the aforementioned locking cylinders.

Furthermore, when using the hydraulic elements and connection configurations, as described in particular in the aforementioned patent application with the official file number 103 56 596.5, conceivable in connection with certain hydraulic switching and line elements that under load to a movement of the piston relative to the Cylinder can come, although the spindle is mechanically locked. This would also mean a significant operational risk.

It is therefore an object of the invention to provide a locking cylinder available, which allows high reliability even with special requirements in terms of use and function and in a simple and space-saving design.

This object is achieved by the features of claim 1, in particular by providing a pawl mechanism containing the locking body movable relative to the cylinder, by means of which a mechanical locking or locking of the spindle in a first direction of rotation about its axis of rotation can be achieved, while or and wherein the spindle is movable in an opposite, second direction of rotation about its axis of rotation to allow movement of the piston along the cylinder.

In a concrete embodiment, it may be provided that the relative to the cylinder movable locking body is pressed by means of the spring force of the spring against the counter locking body delimiting and rotating about the axis of rotation of the spindle step or tooth-shaped control edge, wherein the movable relative to the cylinder locking body and the step or the tooth are designed to be coordinated with each other such that the locking body which is movable relative to the cylinder can engage or engage in its locking position when the spindle is rotated in its first direction of rotation on the step or on the tooth in order to provide a mechanical locking to cause the spindle and wherein the control edge can run at a rotation of the spindle in its opposite, second rotational direction, substantially unhindered on the relative to the cylinder movable locking body along. The spindle is thus always mechanically unlocked in this second direction of rotation.

According to an advantageous embodiment it can be provided that the counter-locking body, preferably the locking body rotatably connected to the spindle locking body, at least one outwardly open locking recess into which acted upon by the spring force of the spring and can engage relative to the cylinder movable locking body.

A particularly simple, space-saving and cost-effective and reliable construction can be achieved if the locking recess with a control edge-containing outlet slope, such as a ramp or inclined plane, is designed for the relative to the cylinder movable locking body.

Furthermore, it can be provided that the locking recess has a trapezoidal cross section in the circumferential direction. As a result, such a locking recess can be produced in a particularly simple and cost-effective manner. A particularly space-saving design in conjunction with advantageous possibilities of further improved operational safety can be achieved in that the locking recess is designed axially, ie in the longitudinal direction of the cylinder, open to the outside.

It is also useful if the locking recess is provided in a hole-disc-shaped approach, which is rotatably connected to the spindle.

The reliability can be further increased if a plurality of locking recesses in the circumferential direction with respect to the axis of rotation of the spindle and spaced from each other. It is particularly advantageous if at least four, preferably at least six locking recesses are provided.

It is particularly advantageous if the relative to the cylinder movable locking body is mounted parallel to the axis of rotation of the spindle axially displaceable on or in a head of the cylinder and in its locking position in an axially outwardly open locking recess or in several axially outward open locking recesses engages.

A particularly space-saving, inexpensive and reliable construction can be achieved if the relative to the cylinder movable locking body is designed as a locking bolt. The locking bolt may advantageously be designed as a cylinder pin, in particular as a circular cylindrical bolt.

It is also particularly advantageous if a plurality of, preferably two, locking bodies movable relative to the cylinder are designed as separately movable locking bolts. As a result, jamming or tilting during locking can be avoided. Such locking bolts are simple and inexpensive to produce and require only a minimal installation and switch room, so that the space gained can be used to advantage for other elements and / or tasks or an overall smaller and lighter locking cylinder can be provided. In addition, only comparatively small locking and unlocking forces are required. As a result, the locking cylinder in the region of the locking unit can be made more space-saving or lighter overall. Also can be achieved by the aforementioned measures significantly reduced locking and unlocking. Finally, when using separately movable locking bolts, no circumferential seals are required between them and the cylinder wall. In this way, therefore, a locking cylinder can be provided, which allows for a simple and space-saving locking construction high reliability and has a good efficiency.

In an advantageous development, it can be provided that a plurality of, preferably two, locking bodies movable relative to the cylinder are movable separately and independently of one another.

According to an advantageous development it can be provided that the relative to the cylinder movable locking body by means of a fluid working means against the spring force of the spring from its locking position can be converted into an unlocking position in which the spindle is rotatable about its axis of rotation. In this way, therefore, the relatively movable relative to the cylinder locking body and thus also the spindle can be hydraulically unlocked, so that when a pressurization of the piston with fluid pressure medium, the piston can be moved with simultaneous rotation of the spindle relative to the cylinder.

Further features, advantages and aspects of the invention can be taken from the following description part, in which a preferred embodiment of the invention is described.

Show it:

Fig. 1

a longitudinal cross section through a locking cylinder according to the invention;

Fig. 2

an enlarged section of the cross section of Figure 1 in the region of the locking bolt shown there on the right;

Fig. 3

a partial view of the non-rotatably connected to the spindle and a hole-disc-shaped design approach, in particular to illustrate the number, arrangement and design of the locking recesses;

Fig. 4

a cross section in a development along the section line A-B in Figure 3 to illustrate the cross-sectional geometry of the locking recesses;

Fig. 5

a hydraulic circuit diagram according to an advantageous embodiment of the invention;

Fig. 6

one of the view in Figure 3 corresponding view of the locking recesses having perforated disc part.

The locking cylinder 20 shown in Figure 1 comprises a cylinder 21 and a longitudinally slidably mounted therein piston 22. The piston 22 is sealed relative to the cylinder inner wall by a ring seal 68 and is on its in the direction of the longitudinal axis 29 of the cylinder 21 facing away from each other pages 44, 46 by a fluid pressure medium, preferably oil, acted upon to allow a pressure-medium-assisted movement of the piston 22 in a direction of unlocking referred to as the second direction or unlocking direction 27 or in a direction also referred to as the first direction of extension 28.

The piston 22 is fixedly connected to a piston rod 23, which, starting from its end face 44 coaxial with Cylinder longitudinal axis 29 extends. The cylinder 20 is closed at its the free end 67 of the spindle 35 side by a piston rod 23 receiving cover 30. On its other side, the cylinder 21 is fixedly connected to a step-shaped projection 66. This is in turn completed by a cylinder bottom 53 forming lid or head 31.

The piston 22 forms a projection 32 which is non-rotatably connected to the piston rod 23. The piston 22 is designed as a tubular hollow body and has an internal thread 34, also referred to as a piston thread. This is engaged with an external thread 36, also referred to as a spindle thread, of a spindle 35 on which the piston 22 is guided. The internal thread 34 of the piston 22 and the external thread 36 of the spindle 35 are preferably designed as eight-speed trapezoidal coarse thread, which together form a non-self-locking thread 37, which is designed here right-handed.

For attachment of the locking cylinder 20, the piston rod 23 at its free end a here designed with an eyelet fastener 25, and a correspondingly shaped fastener 26 is mounted opposite to the head 31 of the cylinder 21.

The pressure medium can be fed via the channels 48 and 49 on both sides 44 and 46 of the piston 22 into a first working chamber 45 and into a second working chamber 33 in order to achieve a movement of the piston 22 along the cylinder 21 in the retraction direction 27 or in the extension direction 28 can. In this case, the first working chamber 45 against the second working chamber 33 sealed via the annular seal 68 of the piston 22.

• Zur Aufnahme der während eines normalen Betriebs des Verriegelungszylinders 20 in der ersten Richtung 28 auf die Spindel 35 wirkenden Betriebs-Axialkräfte, ist ein zweites Axiallager 121 in Form eines zweiten Ringlagers 130 vorgesehen, das an dem kopfseitigen Ende 77 der Spindel 35 angeordnet ist. Dieses Axiallager 121 ist ebenfalls als ein Wälzlager 122 in Form eines Nadellagers 123 gestaltet. Es ist auf einem koaxial zur Drehachse 43 der Spindel 35 fest mit der Spindel 35 verbundenen Stützkörper 124 in Form eines Zylinderbolzens 125 aufgenommen, der sich in Richtung des Zylinderbodens bzw. Kopfes 31 des Zylinders 21 erstreckt und der koaxial zur Drehachse 43 Spindel 35 angeordnet ist.

In the area of the free end 67 of the spindle 35 facing away end 77 of the spindle 35, this is rotatably connected to a flange-shaped projection 65. This has in the region of its cylinder bottom side end a transversely or perpendicular to the axis of rotation 43 of the spindle 35 extending, here annular wall portion 79, which is designed as a perforated disc part 141. This is on the pointing to the free end 67 of the spindle 35 side by a first thrust bearing 120, here in the form of a first ring bearing 127, which is designed here as a needle bearing 138, mounted on a supporting and conditioning stage of the cylinder neck 66. This designed as a rolling bearing 137 ring bearing 127 serves to absorb the force acting on the spindle 35 in the extension direction 28 axial forces. In order to be able to absorb the axial forces acting on the spindle 35 in the retraction direction 27 in the opposite direction to the extension direction 28, two measures are taken:

• For receiving the operating axial forces acting on the spindle 35 during normal operation of the locking cylinder 20 in the first direction 28, a second thrust bearing 121 is provided in the form of a second annular bearing 130 arranged at the head end 77 of the spindle 35. This thrust bearing 121 is also designed as a roller bearing 122 in the form of a needle bearing 123. It is on a coaxial with the axis of rotation 43 of the spindle 35 fixedly connected to the spindle 35 supporting body 124 received in the form of a cylinder pin 125 which extends in the direction of the cylinder bottom or head 31 of the cylinder 21st extends and the coaxial with the axis of rotation 43 spindle 35 is arranged.

Adjoining the needle bearing 123 in the retraction direction 27 is a disc spring package 135, which consists of a plurality of disc springs 134, 136. In this case, the plate springs 134 and the plate springs 136 are each alternately successively preferably arranged such that in each case the spring travel of each plate spring 134, 136 is available for a resilient mounting of the spindle 35. The plate springs 134, 136 are selected with regard to their spring characteristics and arrangement such that in the regular driving operation, when the piston 22 is moved in the retraction direction 27, the thereby transmitted via the non-self-locking thread 37 and the spindle 35 dynamic resultant forces, d. H. be compensated so that the support body 124 is always lifted from the head 31 of the cylinder bottom of the cylinder 21.

When the piston 22 in the opposite direction, d. H. extended in the extension direction 28 acts on the spindle 35, a resultant axial force in the extension direction 28, so that even with this piston movement of the support body 124 is always lifted from the head 31.

Nothing else applies in the case of holding the piston 22 in a desired stroke position. Because then, as will be explained in more detail below, the piston 22 of pressure medium, which is located in the two working chambers 33 and 45 and with these fluid-connected channels 49 and 48, held "clamped", so that even under permissible high static loads, which are to be held or moved by the locking cylinder 20, the Support body 124 is always lifted from the head 31 of the cylinder 21. In this case, therefore, the static load to be retained by means of the locking cylinder 20 and the axial forces transmitted thereto to the spindle 35 are received essentially via the piston 22 and the pressure medium acting on it and via the adjacent cylinder walls.

However, if a claim occurs, so z. B. a leakage or break in the area of a pressure medium line occurs, 27 acting overload axial forces can occur in the retraction direction, which can no longer be received by the small needle bearing 123 without destruction. Because this second needle bearing 123 has a relation to the carrying capacity or the supporting diameter of the first needle bearing 138 smaller capacity or a smaller load-bearing diameter to meet the requirements for the most space-saving design of the locking cylinder 20 in the locking and storage area. Contribute the disc springs 134 and 136, so that upon application of the overload axial forces a displacement of the spindle 35 in the retraction 27 while compressing the plate springs 134, 136 occurs until the support body 124 with the present at its free end support surface 129 on the opposite support surface 131 of the head 31 of the cylinder rests. The support body 124 is then supported there so that the acting overload axial forces are then transferred from the spindle 35 via the support body 124 on the head 131 of the cylinder 21 without the needle bearing 123 would be damaged.

By the arrangement and the selected spring characteristics of the disc springs 134, 136 so a certain force is given, which corresponds to a certain limit axial force at which falls below the support body 124 is lifted and upon reaching or exceeding a displacement of the spindle 35 together with the Support body 124 in the retraction 27 occurs until the support body 124 bears against the head 31 of the cylinder 21.

The flange-shaped projection 65 is provided on the transverse to the axis of rotation 43 of the spindle 35 extending wall part 79 or perforated disc part 141 with here a total of six locking recesses 38.1 to 38.6. The locking recesses 38.1 to 38.6 are each arranged at the same angular intervals on an imaginary circumferential circle 78 such that two locking recesses are arranged diametrically opposite each other.

The exact design and arrangement of the locking recesses 38.1 to 38.6 is shown in particular in Figures 3 and 4. The locking recesses 38; 38.1 to 38.3 are provided at the end facing away from the free end 67 of the spindle 35 end of the rotatably connected to the spindle and designed with a perforated disc part 141 neck 65. Each locking recess 38.1 to 38.6 has a trapezoidal cross section 139 in the sectional plane shown in FIG. In this case, each locking recess 38; 38.1 to 38.6 in the retraction direction 27 to the cylinder bottom 53 towards axially open outward and is bounded laterally by a recess formed with a circular surface 125 Ausnehmungsgrund here normal to the axis of rotation 43 of the spindle 35 is arranged.

Starting from this, formed with a circular surface 125 Ausnehmungsgrund each locking recess 38; 38.3 to 38.6 bounded on the one hand by an approximately perpendicular to the circular surface 125 axially outwardly extending wall to form a step 61 and on the other hand, the recess base is formed in an inclined slope or inclined ramp 81. As a result, the depth of the locking recesses 38, starting from their recess base there, decreases continuously to zero. By this shape and arrangement of circumferentially at equal angular intervals arranged mutually Verriegelungsausnehmungen 38.1 to 38.6 a stepped or tooth-shaped control edge 78 is formed, which is characterized in the view of Figure 3 by a dash-dotted circle concentric with the axis of rotation 43 of the spindle 35 is arranged. A part of this control edge 78 is clearly visible in the cross section according to FIG.

Each locking recess 38; 38.1 to 38.6 is designed with conically inwardly tapering wall portions 70 and serves to receive outwardly conically tapered wall parts 72 of locking bolt 40; 40.1, 40.2. Here, the conical tapered wall parts 72 having free end 57 of the respective locking pin 40 is preferably designed so matched to the locking recesses 38 in the region of their conically tapered wall parts 70, that a Durchströmspalt 71 is formed for the pressure medium. This Durchströmspalt 71 is in fluid communication with a gap 91 which is arranged in the region of the radial edges of both the flange-shaped projection 65 and the opposite part of the head 31 of the cylinder 21. This gap 91 is in fluid communication with a switching channel 47, which in turn Fluid connection with channels 48 and 49 can be brought, via which the piston 22 can be acted upon on its respective sides 44 and 46 with pressure medium.

The locking bolts 40 are designed cross-sectionally closed in the region of their free ends 57. Each locking bolt 40 is designed as a preferably elongated cylinder pin 69 rotationally symmetrical to its longitudinal axis 74. Each locking bolt 40 has a circular cylindrical outer contour 50 and a circular cylindrical inner contour, so it is designed as a rotary hollow body. Each locking bolt 40 also has a circular cylindrical recess 92 which is designed with parallel to the longitudinal axis 74 of the respective locking bolt 40 delimiting wall parts and which is open to the head 31 of the cylinder 21 opposite end 56 to the outside. This recess 92 serves to receive and lateral support of a designed as a compression spring spring 39. This is received in the mounted state with a spring portion 93 in the recess 92. In this case, the spring 39 is supported with one of its ends 95 on an inner surface 94 of a radially inwardly extending support and abutment surface 60 of the locking bolt 40. The other end 96 of the spring 39 is supported on an inner surface of a corresponding support and contact stage 76 of the head 31 of the cylinder 21.

Offset at an axial distance from the inner surface of the supporting and contact stage 76 and in the extension direction 28, a radially outwardly extending abutment and counter-sealing surface 98 is provided for the locking bolt 40, which is arranged perpendicular to the wall portions bounding the bearing recess 75. Every locking bolt 40 has at its head or spring-side end 59 on a ring end edge 99, which is designed with a circumferential annular sealing surface 97 and in the unlocking 27 of the respective locking bolt 40 has. This annular sealing surface 97 is sealingly against the likewise circumferential abutment and counter-sealing surface 98 of the head 31 of the cylinder 21, when the respective locking pin 40 has been transferred to a loading with the force exerted by the pressure medium in unlocking 27 compressive forces in its unlocked position. Under the then effective pressure forces a seal is achieved there, so that no leakage of pressure fluid along the outer surfaces of the respective locking bolt 40 occurs. In addition, the abutment and Abdichtgegenfläche 96 advantageously limits the respective Entriegelungshub the locking pin 40th

Each locking bolt 40 is slidably mounted parallel to the axis of rotation 43 of the spindle 35 with little play in the cylindrical inner contour 98 having bore or bearing recess 75, so starting from the locking position 41 shown in Figures 1 and 2 by means of the pressure medium in extension or Unlocking direction 28 against the spring forces of the spring 39 are moved to its unlocked position, or vice versa after pressure relief in the region of its free locking end 57 of its unlocked position automatically, ie by the force exerted by the respective spring 39 on the respective locking pin 40 return spring forces, be transferred back into its locking position 41. The bearing recess 75 thus has an inner diameter which is slightly larger than the outer diameter of the locking bolt 40.

The locking bolt 40 has at its free end 57 a perpendicular to its longitudinal axis 74 arranged active surface 58 on which the fluid pressure medium can act to transfer the locking pin 40, starting from the locking position 41 shown in Figure 2 in an unlocking position, in which he is out of engagement with the locking recesses 38.1 to 38.6, so no rotation of the spindle 35 in its first direction of rotation 51 is no longer blocked. Upon movement of the locking pin 40 from its unlocking position into its locking position 41, the oil located in the associated locking recesses 38 is displaced via the switching channel 47 into the return channel 87.

In the figures 5 is a hydraulic circuit diagram is illustrated, with particularly advantageous control means and ways are used. It is provided as a load-holding Senkbrems means 150 designated load holding Senkbrems valve, which causes when pressurizing the piston 22 on its second side 44 with the in the second working chamber 45 pressure fluid to form a working pressure, the displacement of the Piston 22 causes in a direction of retraction also referred to as the second direction 27, at the same time in the first working chamber 33 on the first side 46 of the piston 22, a counter-pressure exerted by the pressure medium located in the first working chamber 33 acts. This counter-pressure is less than the working pressure in the second working chamber 45, so that an uncontrolled advance of the piston 22 in the second direction 27 is avoided. At a desired pressure relief at the return passage 87 for the purpose of holding the piston 22 in one desired stroke position, the load-holding lowering brake means 150 blocks a return flow of the pressure medium from the working chamber 33, so that the piston 22 is held securely in the desired stroke position by the pressure medium in the working chamber 33.

The load hold counterbalance valve 150 has an inlet 153, an outlet 154, and a pressure fluid control port 155, the inlet 153 being fluidly connected to the first working chamber 33 via the channel 49. The control port 155 of the load-holding lowering valve 150 is fluidly connected to the return passage 87. With the inlet 153 and the outlet 154 of the load-holding lowering valve 150, a Rückströmsperrmittel 156 is fluidly connected, which allows a flow of the pressure medium from the outlet 154 to the inlet 153, but blocks in the opposite direction.

Of the connected to the outlet 154 of the load-holding lowering valve 150 supply channel 86 branches off into the channel 55 opening channel in which a blocking in this direction check valve 82 is arranged. From the fluidically connected to the switching channel 47, the channel 48 and the switching channel 88 return channel 87 branches off also into the channel 55 emptying channel, in which also a blocking in this direction check valve 83 is arranged.

The locking cylinder 20 shown in the figures is designed for locking under pressure. This means that the locking cylinder 20 for moving or lifting a not closer shown in the figures. Load in the extension direction 27 is used. Act through the to be moved or lifted load on the piston rod 23 against the extension direction 28 acting compressive forces. If the piston rod 23 is to be held under load in any desired position in any desired lifting or extension position, the piston rod 23 is in a stable position with its piston 22 in the desired lifting or extended position by the load-holding lowering valve 150 kept hydraulically secured to the cylinder 21.

In addition to the hydraulic securing by means of the load-holding lowering brake valve 150, a mechanical securing of the locking cylinder 20 via the locking unit 56 is possible. This additional mechanical protection is particularly effective when leakage or failure or similar damage to the hydraulic system occurs. Because then engage the locking pin 40 in the locking recesses 38 and in the said stress on pressure in the direction of retraction 27, this means that due to the forced coupling between the piston 22 and the spindle 35 via the non-self-locking, here right-hand thread 37, the Spindle 35 is caused to turn clockwise in the direction of rotation 51. If, therefore, the locking bolts 40.1, 40.2 in the current lifting or extended position due to the spring force of the spring 39 do not yet protrude into each of the locking recesses 38 and abut there respectively at the steps 61, the spindle 35 in the direction of rotation 51 is still slightly further rotated until the locking pins 40.1, 40.2 abut in the respective locking recesses 38 on the steps 61. In this way, therefore, a unidirectional locking or blocking of the spindle 35 and thus of the piston 22 in the given lifting or extended position reached. This engagement or blocking position of the cylinder bolt 40 is achieved in particular in the moment in which an unwanted, in the channel 49 and thus also in the switching channel 47 impacting pressure relief occurs. Because then the respective locking pin 40 is pressed by the mechanical force of the compression springs 39 against the rotating flange-shaped projection 65 until the respective locking pin 40 engages in the next possible locking recess 38 at its stage 61 and thereby the further rotational movement of the spindle, here in the direction of rotation 51 blocked.

Upon rotation of the spindle 35 in its second direction of rotation 52 rotatably connected to the spindle 35 and the locking recesses 38.1 to 38.6 having approach 65 rotates in the same direction of rotation 52, so that the control edge 78 undergoes a corresponding rotation. The control edge 78 therefore travels in the direction of rotation 52 along the cylinder bolts 40, which are fixed to the cylinder but movable in the axial direction parallel to the spindle rotation axis 43. As a result, perform the locking pin 40 in the course of rotation in the direction of rotation 52 an axial reciprocating motion, while they are held pressed by the spring force of their springs 39 on the control edge 78.

In contrast, ie, when the spindle 35 is acted upon by a force which is induced a rotation of the spindle 35 in its opposite, first direction of rotation 51, provided with the perforated disc part 141 neck 65 and thus the spindle 35 can only so long in turn their first rotational direction 51 until the slightly conically tapered wall portions 72 at the respective free end 57 of the respective locking bolt 40 to the respective Stages 61 of the associated locking recesses 38 abut, whereby a locking or blocking of the spindle 35 in the said direction of rotation 51 is achieved.

By the above-described constructive measures, a kind of pawl mechanism 54 is thus realized, by means of which a mechanical locking of the spindle 35 in a first direction of rotation 51 about its axis of rotation 43 is reached, while the spindle 35 in its opposite second direction of rotation 52 about its axis of rotation 43 substantially free is movable or remains, in particular to allow movement of the piston 22 along the cylinder 21, here in the extension direction 28.

It is understood that the invention is not only applicable to pressure-locking locking cylinders, but of course also in lock locking on locking cylinders. Then, however, the load-holding counterbalance valve 150 would not be associated with the flow channel 86, as shown in FIG. 5, but would be associated with the return channel 87. In such a case, therefore, the outlet 154 of the load-holding lowering valve 150 would be fluidly connected to the return passage 87 and the inlet 153 of the load-holding lowering valve 150 would be fluidly connected to the channel 48 opening into the second working chamber 45. Finally, the switching channel 47 would then not open into the opening into the second working chamber 45 channel 48, but the switching channel 47 in the opening into the first working chamber 33 channel 49. The rest of the construction could remain unchanged.

• Um beispielsweise eine Bewegung des Kolbens 22 und damit der Kolbenstange 23 relativ zu dem Zylinder 22 in der Ausfahrrichtung 28 zu erreichen, wird der hier mit Vorlaufkanal 86 bezeichnete Kanal mit Druckmittel beaufschlagt, d. h. es wird mithilfe einer in den Figuren nicht näher gezeigten Pumpe ein Druckmittel durch den Vorlaufkanal 86 zugeführt.

The operation of the lock cylinder 20 will be described below using the circuit shown in FIG. 5.

• For example, to achieve a movement of the piston 22 and thus the piston rod 23 relative to the cylinder 22 in the extension direction 28, the channel designated here with flow channel 86 is subjected to pressure medium, ie it is by means of a pump not shown in detail a pressure medium supplied through the flow channel 86.

The pressure medium can then flow from the channel 86 via the flow restrictor 173, which is continuous in this direction, into the channel 49, which in turn opens into the first working chamber 33. As a result, the piston 22 is acted upon by pressure on its second side 46, so that a force in the extension direction 28 acts on the piston 22. Due to the forced coupling of the piston 22 with the spindle 35 via the non-self-locking, here right-hand thread 37 acts simultaneously on the spindle 35, a force that induces a rotation of the spindle to the left, ie in its second direction of rotation 52. This rotation of the spindle 35 in its second direction of rotation 52 is substantially unhindered possible, because upon rotation in this direction of rotation 52, the locking pins 40.1, 40.2 pressed against the spring forces of their springs 39 due to the outlet slopes 81 of the locking recesses 38.1 to 38.6 respectively from these locking recesses 38 can be. This is thus made possible in particular by the special design of the trained here as a perforated disc part 141 neck 65 with the locking bolt 40.1 and 40.2 circumferential control edge 78.

In the course of the movement of the piston 22 in its extension direction 28 so make the locking bolt 40 several times a reciprocating motion parallel to the longitudinal axis 29 of the cylinder or parallel to the axis of rotation 43 of the spindle 35, wherein each of their free ends 57 associated contact surfaces are held pressed against the circumferential control edge 78 of the perforated disc part 141 by the spring forces of the springs 39 and are.

On the other hand, to achieve a movement of the piston 22 and thus the piston rod 23 relative to the cylinder 22 in the retraction direction 27, the here designated return channel 87 channel is acted upon with pressure medium, d. H. It is fed by means of the pump not shown in detail by the return passage 87, a pressure medium. This increases the pressure in the downstream channels, i. H. in the switching channel 88 for the load-holding Senkbrems valve 150, in the switching channel 47 for the hydraulic actuation of the locking pin 40 and in the opening into the second working chamber 45 channel 48 at.

The load-holding lowering brake valve 150 is adjusted by a spring pressure so that it opens only above a certain pressure, from which therefore the pressure medium can flow from the inlet 153 to the outlet 154 of the load-holding Senkbrems valve 150. This means that an increase in pressure at the return passage 87 initially causes pressure fluid to flow via the switching channel 47 into the locking recesses 38, as a result of which the locking bolts 40 engaging therein in the extension direction 28 counteract the spring forces of the spring 39 are pushed back, so that therefore the spindle 35 is first unlocked.

In the course of the further increase in the return passage 87 pressure opens the load-lowering valve 150, whereby a movement of the piston 22 in retraction 27 is made possible, because the working medium located in the first working chamber 33 then via the channel 49 through the load holding Senkbrems valve 150 can flow through into the flow channel 86. By means of the load-holding Senkbrems valve 150 always acting back pressure a lead of the piston 22 in the retraction direction 27 is avoided with certainty.

Claims (15)

Locking cylinder (20) with a cylinder (21) and a piston (22) which is movable parallel to the longitudinal axis (29) of the cylinder (21) by means of a preferably two sides (44, 46) of the piston (22) can be fed, and which is provided with a piston thread (34) which, forming a non-self-locking thread (37), engages with a spindle thread (36) of a mechanically lockable spindle (35) which is parallel to the longitudinal axis (29) of the cylinder (35). 21) is rotatable and has at least one first locking body (175), wherein at least one second locking body (42; 42.1, 42.2) is provided, which is connected to the cylinder (21) and wherein at least one of the locking body (42, 42.1, 42.2) is movably mounted relative to the cylinder (21) and by means of a spring force of at least one spring (39) from an unlocking position, in which the spindle (35) about its axis of rotation (43) is rotatable, in a locking position (41) can be transferred, in which it with the other, a counter-locking body forming the locking body (175) in one Locking engagement is such that then rotation of the spindle (35) about its axis of rotation (43) is blocked in a rotational direction (51),
characterized,
in that a pawl mechanism (54) containing the locking body (42; 42.1, 42.2) movable relative to the cylinder is provided, by means of which a mechanical blocking of the spindle (35) in a first direction of rotation (51) about its axis of rotation (43) can be achieved; while the spindle (35) in an opposite second rotational direction (52) about its axis of rotation (43) is movable. Locking cylinder according to claim 1, characterized in that the relative to the cylinder movable locking body (42; 42.1, 42.2) by means of the spring force of the spring (39) against a counter-locking body (175) limiting and about the axis of rotation (43) of the spindle (35) is pressed round stepped or tooth-shaped control edge (78), wherein the relative to the cylinder (21) movable locking body (42) and the step (61) or the tooth are designed so coordinated that the relative to the cylinder (21) movable locking body (42) upon rotation of the spindle (35) in its first rotational direction (51) on the step (61) or on the tooth in its locking position (41) engage or strike to a mechanical locking of the spindle (35), and wherein the control edge (78) at a rotation of the spindle (35) in its opposite second direction of rotation (52) substantially unhindered at the relative to the cylinder ( 21) movable locking body (42; 42.1, 42.2) can run. Locking cylinder according to claim 1 or 2, characterized in that the counter-locking body (175), preferably of the spindle (35) rotatably connected locking body (175), at least one outwardly open locking recess (38, 38.1 to 38.6), in which can engage the locking body (42; 42.1, 42.2) that is acted upon by the spring force of the spring (39) and can move relative to the cylinder (21). Locking cylinder according to Claim 3, characterized in that the locking recess (38; 38.1 to 38.6) is designed with a run-off slope (81; 81.1 to 81.6) containing a control edge (78) for the locking body (42; 42.1, 42.2) which is movable relative to the cylinder is. Locking cylinder according to claim 3 or 4, characterized in that the locking recess (38; 38.1 to 38.6) in the circumferential direction (142) has a trapezoidal cross-section (139). Locking cylinder according to one of claims 3 to 5, characterized in that the locking recess (38; 38.1 to 38.6) is open axially outward. Locking cylinder according to one of claims 3 to 6, characterized in that the locking recess (38; 38.1 to 38.6) is provided in a hole-shaped projection (65) which is non-rotatable with the Spindle (35) is connected. Locking cylinder according to one of claims 3 to 6, characterized in that a plurality of locking recesses (38.1 to 38.6) in the circumferential direction (142) relative to the axis of rotation (43) of the spindle (35) and spaced from one another. Locking cylinder according to claim 8, characterized in that at least four, preferably at least six locking recesses (38.1 to 38.6) are provided. Locking cylinder according to one of claims 1 to 9, characterized in that the relative to the cylinder (21) movable locking body (42; 42.1, 42.2) parallel to the axis of rotation (43) of the spindle (39) axially displaceably on a head (31) of the cylinder (21) is mounted and in its locking position (41) in an axially outwardly open locking recess (38) or in axially outwardly open locking recesses (38.1 to 38.6) engages. Locking cylinder according to one of claims 1 to 10, characterized in that the relative to the cylinder (21) movable locking body (42; 42.1, 42.2) as a locking bolt (40; 40.1, 40.2) is designed. Locking cylinder according to claim 11, characterized in that the locking bolt (40; 40.1, 40.2) is a cylinder bolt (69), preferably a circular cylindrical bolt (69) is. Locking cylinder according to one of claims 1 to 12, characterized in that a plurality, preferably two relative to the cylinder (21) movable locking body (42.1, 42.2) are designed as a separately movable locking pin (40.1, 40.2). Locking cylinder according to one of claims 1 to 13, characterized in that a plurality, preferably two relative to the cylinder (21) movable locking body (42.1, 42.2) are separately and independently movable. Locking cylinder according to one of claims 1 to 14, characterized in that relative to the cylinder (21) movable locking body (42; 42.1, 42.2) by means of a fluid working means against the spring force of the spring (39) from its locking position (41) in one Unlocking position can be transferred, in which the spindle (35) about its axis of rotation (43) is rotatable.

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