Lock cylinder and method for measuring a piston travel of a piston of the lock cylinder

Abstract

The invention relates to a locking cylinder (20) comprising a cylinder (21) extending in the direction of a cylinder longitudinal axis (25) and a piston (22), which is movable in an axial direction (59) parallel to the cylinder longitudinal axis (25) relative to the cylinder (21) by means of a fluid pressure medium, but is rotationally fixed to the cylinder (21). The piston (22) is rotationally fixed to a first threaded body (24), the first thread (26) of which engages with a second thread (28) of a frictionally and automatically lockable second threaded body (30) to form a non-self-locking thread (27). The second threaded body (30) is rotatable about an axis of rotation (33) extending parallel to the cylinder longitudinal axis (25) of the cylinder (21) relative to the cylinder (21) and axially movable relative to the cylinder (21) in the axial direction (59).According to the invention, an integrated rotary encoder (85) is provided for detecting a change in the angle of rotation of the second threaded body (30) when it rotates about the axis of rotation (33) relative to the cylinder (21), by means of which it is possible to measure a piston travel that the piston (22) travels when the second threaded body (30) rotates about the axis of rotation (33) in the axial direction (59) relative to the cylinder (21).

Description

[0001] The invention relates to a locking cylinder with the features of the preamble of claim 1. The invention also relates to a method for measuring a piston travel of the piston of such a locking cylinder. Technological background and state of the art

[0002] Locking cylinders of the type mentioned above are known, for example, from the applicant's German patent applications DE 10 2005 016 090 A1, DE 10 2010 015 996 A1 and DE 10 2015 108 829 A1, as well as the European patent applications EP 1 710 449 A1, EP 2 239 470 A2, EP 2 570 679 A1, EP 2 570 680 A1 and EP 3 101 283 A1. These locking cylinders offer high operational reliability over a long period, even under heavy loads, despite special requirements regarding application and function, a comparatively simple and space-saving design, and relatively low manufacturing costs. In addition to a friction-locked and self-locking spindle, separate locking elements are used for the mechanical locking of the spindle in order to reliably prevent rotation of the spindle around its axis of rotation relative to the cylinder.For example, one or more separate locking elements, in particular one or more locking bolts, or one or more single- or double-acting clamping cones can be used as locking elements. The content of the aforementioned patent applications is incorporated here in its entirety, particularly for disclosure purposes, so as not to limit the effect of the locking cylinder according to the invention as prior art, in relation to subsequently filed patent applications, to those embodiments described in the present patent application and illustrated in the figures. Summary of the invention

[0003] The invention is based on the objective of providing a locking cylinder of the type mentioned above, which, in a comparatively simple and cost-effective design, is configured such that it enables the measurement of the piston's axial travel relative to the cylinder when the second threaded body (spindle or nut) rotates about its axis of rotation. The invention is also based on the objective of providing a method for measuring the piston's axial travel in such a locking cylinder, by means of which the piston's axial travel relative to the cylinder can be determined when the second threaded body (spindle or nut) rotates about its axis of rotation.

[0004] This problem is solved with regard to the locking cylinder, in particular by the features of claim 1. Accordingly, the invention relates to a locking cylinder, preferably pressure-medium operated or pressure-medium-operated, comprising a cylinder extending in the direction of a cylinder longitudinal axis and a piston comprising a first piston side, preferably associated with a first working chamber of the cylinder, and a second piston side pointing away from it, preferably associated with a second working chamber of the cylinder, and which is movable relative to the cylinder in an axial direction parallel to the cylinder longitudinal axis, preferably in a first direction and in a second direction opposite to the first direction, by means of a fluid pressure medium that can be supplied to the first piston side or the second piston side or the first piston side and the second piston side, but is rotationally fixed to the cylinder.wherein the piston is rotationally fixed to a first threaded body (nut or spindle), the first thread of which (nut thread or spindle thread) engages with a second thread (spindle thread or nut thread) of a second threaded body (spindle or nut) that can be locked by friction and, for example, by gravity or by the action of an external (resulting) longitudinal force, automatically, in particular mechanically, forming a non-self-locking thread, and wherein the second threaded body (spindle or nut) is rotatable about an axis of rotation extending parallel to the longitudinal axis of the cylinder and axially movable or displaceable relative to the cylinder in the axial direction, wherein according to the invention it is provided that an integrated rotary encoder or rotary angle encoder, in particular an incremental encoder or incremental rotary encoder,for recording the change in the angle of rotation of the second threaded body (spindle or nut) as it rotates around the axis of rotation relative to the cylinder, by means of which a measurement of the piston travel is made possible, which the piston travels in the axial direction relative to the cylinder when the second threaded body (spindle or nut) rotates around the axis of rotation. The adjective "rotatable" used in this patent is synonymous with the adjective "rotationally resistant".

[0005] The locking cylinder according to the invention can be used particularly advantageously in the assembly of formwork in formwork construction, especially in building construction, in order to be able to mount formwork elements, especially formwork panels, at a specific dimensional distance to each other adapted to the respective application, without having to measure the distance separately, as was previously the case especially when using threaded spindles or formwork anchors.

[0006] The locking cylinder according to the invention can also be called a security cylinder. The locking cylinder according to the invention can be a single-acting or a double-acting locking cylinder. The first thread and the second thread each have the same constant pitch. The first thread and the second thread can each be a multi-start thread, in particular a steep thread, preferably a trapezoidal thread. Preferably, an eight-start thread can be used. The locking cylinder according to the invention can be mechanically locked by means of one or more additional locking elements. The locking cylinder according to the invention can also be mechanically locked by means of single- or double-acting clamping cones.In particular, it may be provided that the second threaded body (spindle or nut) can be mechanically locked against rotation about the axis of rotation relative to the cylinder by means of at least one locking element (force-locking and / or friction-locking).

[0007] Preferably, a first working chamber can be assigned to the first piston side, and a second working chamber can be assigned to the second piston side pointing away from it. The piston is movable in an axial direction parallel to the cylinder's longitudinal axis in a first direction and in a second direction opposite to the first, but rotationally fixed to the cylinder, by means of a fluid pressure medium supplied to the first piston side via a first working channel opening into the first working chamber and to the second piston side via a second working channel opening into the second working chamber.

[0008] According to a particularly preferred embodiment, it can be provided that several signals (pulses) proportional to the change in the angle of rotation of the second threaded body (spindle or nut) can be generated or are generated by means of the rotary encoder, which are proportional to the piston travel distance of the piston which it travels in the axial direction relative to the cylinder when the second threaded body (spindle or nut) is rotated about the axis of rotation.

[0009] According to a particularly preferred embodiment, it can be provided that, for detecting the change in the angle of rotation of the second threaded body (spindle or nut) by means of the rotary encoder, a rotating body (timing disk) having an outer circumference is provided, which is rotationally fixed, preferably rigidly, connected to the second threaded body (spindle or nut) and which has a tooth profile or toothing profile on its outer circumference, which extends in a circumferential direction around the axis of rotation of the second threaded body (spindle or nut), for triggering the signals that can be generated or have been generated by means of the rotary encoder.

[0010] It is preferable that the tooth profile be provided with a plurality of grooves arranged around the outer circumference of the rotating body in the circumferential direction at equal circumferential angles to one another about the axis of rotation. The grooves can extend in the axial direction and can be bounded by groove walls formed by the tooth flanks of teeth of the tooth profile. This allows for particularly advantageous signal acquisition by means of the rotary encoder (sensor).

[0011] In a particularly preferred embodiment, each groove, viewed circumferentially around the axis of rotation of the second threaded body (spindle or nut), has the same groove width between its associated groove walls. In this combination with the aforementioned measures, signal acquisition and evaluation can be performed with significantly higher accuracy, allowing the piston stroke to be measured with correspondingly greater precision.

[0012] According to a particularly preferred embodiment, the opposing groove walls of each groove can be designed parallel, preferably perpendicular, to the axis of rotation of the rotating body or the second threaded body (spindle or nut), and / or each groove of the grooves has a substantially planar groove base, also referred to as a tooth root, which is designed perpendicular to the associated groove walls. This enables particularly cost-effective manufacturing and advantageous signal acquisition.

[0013] According to an advantageous embodiment, it can be provided that each groove of the grooves is produced by removing material from a starting rotating body, in particular by machining, preferably by milling.

[0014] According to a particularly preferred embodiment, the rotary encoder can be an inductive and / or pressure-resistant sensor. The rotary encoder or sensor can also be referred to as an encoder or encoder. This enables a cost-effective design and particularly advantageous signal acquisition in combination with the rotary body equipped with slots and teeth.

[0015] Preferably, the rotary encoder is mounted in an outer wall of the cylinder directly opposite the tooth profile, preferably in a detachable manner. This allows for a further improvement in line with the aforementioned advantages.

[0016] The inventive problem is solved with regard to the method by a method for detecting or measuring a piston travel of the piston of the locking cylinder according to the invention, in particular according to one of claims 1 to 10, in which the change in the angle of rotation of the second threaded body (spindle or nut) is detected by means of the rotary encoder during the rotation of the second threaded body (spindle or nut) about the axis of rotation relative to the cylinder.

[0017] It may be provided that, by means of the rotary encoder, several signals (pulses) proportional to the change in the angle of rotation of the second threaded body (spindle or nut) are generated during the rotation of the second threaded body (spindle or nut) around the axis of rotation, which are proportional to the piston travel in the axial direction during the rotation of the second threaded body (spindle or nut) around the axis of rotation, so that an integrated measurement of the piston travels in the axial direction relative to the cylinder is possible or is carried out.

[0018] According to a preferred embodiment, the signals generated by the rotary encoder can be evaluated (decoded) using a signal evaluation unit (decoder). In particular, it can be provided that the piston travel, which the piston travels in the axial direction relative to the cylinder during a rotation of the second threaded body (spindle or nut) about the axis of rotation, is determined or measured by means of a signal evaluation unit coupled to the rotary encoder for the evaluation of the signals generated by the rotary encoder.

[0019] Preferably, the signals generated by the rotary encoder can be incremental signals. Preferably, the signals can be designed such that, viewed over time, a trapezoidal or rectangular signal profile results. To detect the change in the angle of rotation and consequently the piston travel or stroke, a sequence of signals can be generated by the rotary encoder during the rotation of the second threaded body (spindle or nut) about its axis of rotation.During the rotation of the second threaded body (spindle or nut) around its axis of rotation, a sequence of signals is generated by the rotary encoder. In this sequence, a signal rising over time is followed by a signal falling over time, and a signal falling over time is followed by a signal rising over time. Each rising signal and the subsequent falling signal have a first signal interval, and each falling signal and the subsequent rising signal have a second signal interval equal to the first. In other words, the signal interval from a rising edge to a falling edge can be equal to the signal interval from a falling edge to a rising edge.

[0020] It goes without saying that the aforementioned measures can be combined with each other as desired, within the limits of feasibility.

[0021] An advantageous embodiment of the invention is described below with reference to the figures. Brief description of the characters

[0022] They show Figure 1 is a perspective view of a locking cylinder in a partially cutaway view; Figure 2 is an enlarged perspective view of the cylinder shown in the Figure 1 The part of the locking cylinder shown on the right is shown in a partially cutaway view; Figure 3 is a perspective view of a rotating body of the locking cylinder for detecting a change in the rotation angle of the spindle of the locking cylinder by means of the part shown in the Figures 1 and 2 The rotary encoder shown during a rotation of the rotating body about the spindle axis relative to the cylinder; Figure 4 shows a greatly enlarged section of the rotating body according to the Figure 3 ; Figure 5.1 the body of revolution according to Figure 3 in a top view from the right; Figure 5.2 a greatly enlarged section of the body of revolution in a top view according to Figure 5.1 Figure 5.3 shows a cross-section of the rotating body containing the spindle axis of rotation; Figure 5.4 shows the rotating body in a side view; Figure 6.1 shows a first signal diagram illustrating signals from the rotary encoder over time, generated by the encoder during a rotation of the spindle together with the rotating body about the spindle axis of rotation; Figure 6.2 shows a greatly enlarged section of the signal diagram according to Figure 6.1with representation of a rising signal edge and a falling signal edge; Figure 7.1 a second signal diagram illustrating signals from the rotary encoder over time, generated by the rotary encoder during a rotation of the spindle together with an alternative rotating body not shown in the figures about the spindle axis of rotation; Figure 7.2 a greatly enlarged section of the signal diagram according to Figure 7.1 with a representation of a rising signal edge and a falling signal edge. Detailed description of the figures

[0023] In Figure 1A locking cylinder 20, which can be locked under pressure, is illustrated in a partially longitudinally cut-open view. The locking cylinder 20 comprises a cylinder 21 and a piston 22 mounted therein so as to be slidably axially 59, but rotationally fixed to the cylinder 21. The piston 22 is sealed against the inner wall of the cylinder 21 by at least one ring seal 37 and can be acted upon on its sides 23.1, 23.2, which point away from each other in the direction of the longitudinal axis 25 of the cylinder 21, by a fluid, in particular hydraulic, pressure medium, preferably oil, in order to enable pressure-medium-assisted movement of the piston 22 in a first direction 31 or in a second direction 32 perpendicular to the first direction 31. The first direction 31 is the extension direction of the piston 22. The second direction 32 is the retraction direction of the piston 22.The pressure medium can be supplied via a first working channel on the side 23.1 of the piston 22 facing a cylinder base 40 into a first working chamber 48 in order to enable movement of the piston 22 along the cylinder 21 in the first direction 31. Furthermore, the pressure medium can be supplied via a second working channel on a second side 23.2 of the piston 22, which faces away from its first side 23.1, into a second working chamber 49 in order to enable movement of the piston 22 along the cylinder 21 in the second direction 32.

[0024] The piston 22 is connected to a first threaded body 24, here a nut, in a rotationally fixed, preferably rigid, manner. The first threaded body 24 has a first thread 26 designed as an internal thread, which can also be referred to as a nut thread or piston thread. The first thread 26 engages with a second thread 28 of a frictionally and automatically lockable second threaded body 30, here a spindle, forming a non-self-locking thread 27. The second thread 28 can also be referred to as a spindle thread. The first thread 26 and the second thread 28 each have the same constant pitch. The second threaded body 30, or the spindle, is rotatable about an axis of rotation 33 extending parallel or coaxially to the longitudinal axis 25 of the cylinder 20 and is axially movable, preferably only slightly, relative to the cylinder 20 in the axial direction 59.The first thread 27 and the second thread 28 are each a multi-start, preferably eight-start, trapezoidal steep thread.

[0025] The first working chamber 48 is sealed against the second working chamber 49 by at least one ring seal 37 of the piston 22. The at least one seal 37 is supported in an annular groove of the piston 22, which opens outwards towards the inner wall of the cylinder. The piston 22 forms a projection that is rotationally fixed to the piston rod 22.1. The piston rod 22.1 extends from the annular second side 23.2 of the piston 22 in the first direction 31 parallel or coaxial to the longitudinal axis 25 of the cylinder 21 or to the axis of rotation 33 of the spindle 30 away from the piston 22. A second spherical bearing 47.2 is attached to the end of the piston rod 22.1 that projects beyond the cylinder 21 in the first direction 31, in order to allow the locking cylinder 20 to be attached in this area to a second body not shown in the figures (spherical bearing attachment).The piston 22 is designed as a tubular hollow body and has an internal thread, also referred to as the piston thread 26. The piston 22 can also be referred to as a piston nut. The piston thread 26 engages with an external thread, also referred to as the spindle thread 28, of the spindle 30 on which the piston 22 is guided or supported. The piston thread 26 and the spindle thread 28 form a non-self-locking thread 27. Preferably, the non-self-locking thread 27 is right-handed, but it can also be left-handed. Preferably, the piston thread 26 and the spindle thread 28 are each designed as a single, in particular multi-start, preferably trapezoidal thread, especially a steep thread. Preferably, an eight-start steep thread can be used. The cylinder 21 is closed at its end corresponding to the free end 71 of the spindle 30 by a cover 40.1 that receives the piston rod 22.1. This can be, as in . Figure 1The cylinder 21 is shown to be integrally connected to or manufactured with the cylinder 21; however, it can also be connected to the cylinder 21 in multiple parts. The ring-shaped piston cover 40.1 encloses the piston rod 22.1 and has an annular groove open towards the piston rod 22.1. A ring seal is supported in this annular groove, which seals the second working chamber 49 to the outside. On its other side, the cylinder 21 is closed by a cover or head forming the cylinder base 40. In the illustrated embodiment, the cylinder base 40 is connected to the cylinder 21 in multiple parts; however, it can also be connected to the cylinder in one part. In this embodiment, the cylinder base 40 is part of a first spherical bearing 47.1 to allow the locking cylinder 20 to be attached in this area to a first body not shown in the figures (spherical bearing attachment).It is understood that, depending on the application, the first spherical bearing 47.1 could also be omitted. In that case, a shaft extending coaxially to the axis of rotation 33 of the rotating body 85 or the spindle 30 could be fixedly attached to the rotating body 85. This shaft extends coaxially to the axis of rotation 33 from the inside, i.e., from the space or chamber 75, through an opening in the part or cover of the cylinder containing the cylinder base, and is sealed. Accordingly, the rotary motion of the rotating body 85 could be transmitted to the outside via such a shaft. Another commercially available rotary encoder or sensor, which would not need to be pressure-resistant, could be attached to the outwardly extending section of this shaft. This sensor could then be used to detect or measure the piston travel or stroke of the piston 22.

[0026] The spindle 30 is rotatable about a rotation axis 33 arranged parallel or coaxial to the longitudinal axis 25 of the cylinder 21 relative to the cylinder 21 and is also only slightly axially displaceable relative to the cylinder 21 in the axial direction 59 or parallel to the longitudinal axis 25 of the cylinder 21. In the illustrated embodiment, the axial displaceability of the spindle 30, indicated by the double arrow 34, or the axial spindle play, is only about 1.0 to 1.5 mm. The spindle 30 is frictionally locked, i.e., force-locked by friction, and in the illustrated embodiment, it can be locked automatically by a load 29 acting on the piston 22, without a drive and without the influence or support of energy storage devices, for example, tension or compression springs. In other words, the spindle 30 is self-locking, and according to the invention, it is doubly self-locking.For this purpose, two locking support bodies 35, 36 are provided in the area of ​​the end 69 pointing away from the free end 71 of the spindle 30, which in this case is the cylinder-bottom end 69 of the spindle 30. These support bodies can be brought into a mutual frictional locking engagement. They are designed to be able to lock the spindle 30 frictionally against rotation about its axis of rotation 33 and to be able to absorb axial forces acting on the spindle 30 in the second direction 32, in the illustrated embodiment such that the spindle 30, in the locked state, is supported against movement in the second direction 32 on the cylinder 21, here on its cylinder bottom 40. The first locking support body 35 of the locking support bodies 35, 36 is rotationally fixed, preferably rigidly, connected to or attached to the spindle 30.The second locking support body 36 of the locking support bodies 35, 36 is rotationally fixed, preferably rigidly, connected to the cylinder 21 or to the cylinder base 40 or attached to the cylinder 21, here to the cylinder base 40, preferably in one piece.

[0027] The spindle 30 is supported by two axial bearings 38, 39 arranged at a distance from each other in the axial direction 59. A first axial bearing 38 is designed to absorb axial forces acting on the spindle 30 in the first direction 31. The second axial bearing 39 of the axial bearings 38, 39, functioning as a fluid sliding bearing, is designed to absorb axial forces acting on the spindle 30 in the second direction 32.

[0028] The spindle 30 is further provided with a first bearing body 41, which has a first bearing surface 43 opposite a second bearing surface 44 of a second bearing body 42, here the cylinder base 40, which is rotationally fixed, preferably rigidly, to or attached to the cylinder 21. The first bearing surface 43 of the first bearing body 41 and the second bearing surface 44 of the second bearing body 42 form the second axial bearing 39. The second axial bearing 39 is designed as a fluid sliding bearing 45, preferably hydrostatic. This bearing can be pressurized, in particular via a first fluid channel 46, with a fluid pressure medium. The first locking support body 35 is designed as a first clamping cone body 53 having first locking conical surfaces 51 and acting as a self-locking element. The second locking support body 36 is designed as a second locking cone surface 52, self-locking orA second clamping cone body 54 is designed to act as a self-locking element. The locking cone surfaces 51, 52 of the clamping cone bodies 53, 54 can be self-lockingly clamped together. For this purpose, the clamping cone body 53, which is fixed to the spindle 30 in a rotationally fixed manner, can be displaced in the second direction 32 parallel to the longitudinal axis 25 of the cylinder 21 relative to it, until its locking cone surfaces 51 abut the opposing locking cone surfaces 52 of the second clamping cone body 54. The clamping cone bodies 53, 54 can then be self-lockingly clamped together by frictional friction. In this way, not only is a friction-fit self-locking mechanism of the spindle 30 with respect to a rotation about its axis of rotation 33 relative to the cylinder 21 achievable, but also a locking mechanism of the spindle 30 against a movement orDisplacement in the axial direction 59, especially also in the first direction 31. This locking mechanism is therefore a type of double self-locking locking mechanism.

[0029] The clamping cone bodies 53 and 54 are each designed in a frustoconical shape. The first clamping cone body 53, which is rotationally fixed to the spindle 30, is designed as a conical disk, also referred to as a rotating body, or as a frustoconical disk 55. The rotating body 55 is a conical bushing. The rotating body 55 can also be referred to as a timing disk. The rotating body 55 is rotationally symmetrical about the axis of rotation 33 of the spindle 30 and rotationally symmetrical about the longitudinal axis 25 of the cylinder 21. The first clamping cone body 53 and the second clamping cone body 54 are rotationally symmetrical about the axis of rotation 33 of the spindle 30 and rotationally symmetrical about the longitudinal axis 25 of the cylinder 21, respectively.

[0030] The first clamping cone body 53 is received or arranged in a recess 75 of the cylinder base 40, which is designed as a chamber. The recess 75 is preferably also rotationally symmetrical about the longitudinal axis 25 of the cylinder 21 or rotationally symmetrical about the axis of rotation 33 of the spindle 30. The first clamping cone body 53 is rotationally fixed to a threadless portion 50 of the spindle 30, which in turn is rotationally fixed to the portion of the spindle 30 having the spindle thread 28. The portion 50 of the spindle 30 without a spindle thread is received in a bore of a projection 72 extending radially inwards and transversely to the longitudinal axis 25 of the cylinder 21. The projection 72 is arranged between the first clamping cone body 53 and the first working chamber 48.The projection 72 has an annular groove open to the unthreaded part 50 of the spindle 30, against the wall of which a ring seal 76 is supported. The recess or chamber 75 is sealed against the first working chamber 48 by means of the ring seal 76.

[0031] In the illustrated embodiment, the first locking support body 35 and the first bearing body 41 are manufactured in one piece and each form a common first locking support and bearing body 61, here in the form of the rotating body or the indexing disk 55. The second locking support body 36, formed by part of the cylinder base 40, and the second bearing body 42 are also manufactured in one piece and form a common second locking support and bearing body 62. The first locking support and bearing body 61 is designed as a self-locking or self-locking first clamping cone body 53 having first locking cone surfaces 51. The second locking support and bearing body 62 is designed as a second locking cone body 54 having a second locking cone surface 52, self-locking or self-locking acting clamping cone body 54.

[0032] The first locking cone surfaces 51 of the rotating body 55 or first clamping cone body 53, which is rotationally fixed to the spindle 30, enclose a first inclination angle 63 with the axis of rotation 33 of the spindle 30 ( Figure 5.4 ). The second locking cone surfaces 52 of the cylinder bottom clamping cone body 54 enclose a second inclination angle 64 with the longitudinal axis 25 of the cylinder 21 or with the rotational axis 33 of the spindle 30 ( Figure 2The angle of inclination 63 and the angle of inclination 64 are equal. These angles of inclination 63 and 64 are preferably each approximately 6.5 degrees. At these angles of inclination 63, 64, or more generally at angles of inclination of approximately 4 to approximately 13 degrees, preferably from 4 to 10 degrees, a self-locking mechanism can be achieved when the first clamping cone body 53 and the second clamping cone body 54 are placed next to or inserted into one another, depending on the selected material pairing and other parameters. This self-locking mechanism prevents the first clamping cone body 53 and the second clamping cone body 54 from rotating relative to each other about the longitudinal axis 25 or about the axis of rotation 33, and also prevents them from moving or sliding relative to each other in the axial direction 59, i.e., also not in the first direction 31, i.e., away from each other. This is because a self-locking mechanism occurs due to the clamping of the respective two clamping cone bodies 53, 54.

[0033] The first clamping cone body 53 is designed as an external cone 56, while the second clamping cone body 54 is designed as an internal cone 57. The first clamping cone body 53 tapers conically towards the axis of rotation 33 of the spindle 30 and away from the piston 22 and towards the cylinder base 40 of the cylinder 21. The first locking conical surfaces 51 of the first clamping cone body 53, which is rotationally fixed to the spindle 30, are arranged on its side 65 facing away from the piston 22 and towards the cylinder base 40 of the cylinder 21. The second locking cone surfaces 52 of the second clamping cone body 54, which is rotationally fixed to the cylinder 21, are arranged on its side 66 facing towards the piston 22 and away from the cylinder base 40. The second bearing body 42 is formed with a part of the cylinder base 40 of the cylinder 21.

[0034] The first clamping cone body 53 is supported by the first axial bearing 38 on the extension 72 or cylinder base 40, which is fixedly, preferably rigidly, connected to the cylinder 21. Preferably, the first axial bearing 38 is a roller bearing designed as a needle bearing in the form of a ring bearing. This needle bearing is partially received in a bearing ring groove, which is formed coaxially with the longitudinal axis 25 of the cylinder 21. The bearing ring groove defines the chamber or recess 75.

[0035] The recess 75, in which the first clamping cone body 53 is axially displaceable in the axial direction 59, is bounded on one side by a part of the cylinder base 40 of the cylinder 21 and on the other side by the projection 72. The chamber or recess 75 has a T-shaped cross-section.

[0036] The first fluid channel 46, through which the fluid sliding bearing 45 can be pressurized, opens into a region of the recess 75 that contains or intersects the longitudinal axis 25 of the cylinder 21. Accordingly, the first fluid channel 46 opens onto a first side 65 of the first clamping cone body 53, which is associated with its first locking cone surfaces 51 inclined towards the axis of rotation 33 of the spindle 30. In the region of the other side 66 of the first clamping cone body 53, a second fluid channel opens into the recess 75, preferably directly adjacent to the first locking cone surfaces 51 of the first clamping cone body 53. In the locked state, in which the locking cone surfaces 51; 52 of the clamping cone body 53; 54 are adjacent to each other, the first fluid channel 46 and the second fluid channel are separated from each other and sealed against each other by a part of the first clamping cone body 53 containing the first locking cone surfaces 51.

[0037] Viewed in a projection perpendicular to the axis of rotation 33 of the spindle 30, or in a corresponding section plane, the first bearing surface 43 of the first clamping cone body 53 is larger than a spindle surface of the spindle 33 located on the side 83 of the seal 76 sealed by the seal 76 from the recess 75 which at least partially accommodates the first clamping cone body 53, and this seal 76 being in fluid communication with the first working chamber 48. This spindle surface is an annular surface that is bounded on one side in the radial direction by the cylindrical outer surface of the part 50 of the spindle 30 not provided with the spindle thread, and on the other side by the outer diameter or external thread 28 of the spindle 30.The first bearing surface 43 of the first clamping cone body 53, which can be subjected to the fluid pressure medium, has an outer diameter 80 that is larger, preferably much larger, than the inner diameter 81 of the seal 76 or than the outer diameter 82 of the unthreaded part 50 of the spindle 30.

[0038] The operation of the locking cylinder 20 is described in more detail below: In the rest state, in which neither the first working channel nor the fluid channel 46 is pressurized with pressure medium, i.e., when the pressure medium system is pressureless, the spindle 30 is doubly self-locking relative to the cylinder 21 against rotation about its axis of rotation 33 and against lifting in the first direction 31 ( Figures 1 and 2Starting from this locking position, for example, for the purpose of extending the piston 22 and lifting the load 29 in the first direction 31, pressure medium can be supplied either first via the first fluid channel 46 and then via the first working channel, or preferably simultaneously via the first fluid channel 46 and the first working channel, so that accordingly either the recess 75 and then the first working chamber 48 are pressurized with pressure medium first, or preferably the recess 75 and the first working chamber 48 are pressurized with pressure medium simultaneously. In the course of this, the self-locking clamping between the first clamping cone body 53, which is rotationally fixed to the spindle 30, and the second clamping cone body 54, which is rotationally fixed to the cylinder 21, is released, whereupon the spindle 30, and optionally also the piston 22 simultaneously, is moved in the first direction 31, i.e., lifted.Initially, there is no or essentially no rotation of the spindle 30 about its axis of rotation 33 relative to the cylinder 21. However, as soon as, or at the latest when, the first clamping cone body 53, which is non-rotatably connected to the spindle 30, comes into contact with the first axial bearing or rolling bearing 38, the spindle 30 begins to rotate about its axis of rotation 33 due to friction. This, and the threaded connection to the spindle 30 via the non-self-locking thread 27, allows the piston 22 to move in the first direction 31, i.e., in the extension direction or upwards, thereby moving or lifting the load 29 in the first direction. During this movement of the piston 22 in the first direction 31, hydraulic fluid flows through the first working channel into the first working chamber 48, and simultaneously, any hydraulic fluid present in the second working chamber 49 flows out through the second working channel.During this movement of the piston 22 in the first direction 31, the fluid sliding bearing 39 is pressurized with pressure medium in such a way that the clamping cone bodies 53, 54 are separated from each other, in particular lifted off each other in such a way that their locking cone surfaces 51, 52 do not touch, so that the locking cone surfaces 51, 52 are in a lifting and unlocking position.

[0039] If the piston 22, moving in the first direction 31, is to be stopped, the first working channel can be depressurized. If both the first working channel and the first fluid channel 46 are depressurized, the piston 22, together with the spindle 30 and the rotating body 85 or first clamping cone body 53, which is non-rotatably connected to it, moves in the second direction 32 due to the load 29 acting in the second direction 32, specifically by the intended small axial play of, preferably only about 1.0 to 1.5 mm, until the first clamping cone body 53 is self-lockingly clamped against or in the second clamping cone body 54.

[0040] It is understood, however, that if necessary only the first working channel can be depressurized, but not the first fluid channel 46, so that during the stopping of the piston 22 the fluid sliding bearing 45 is still pressurized and accordingly the first clamping cone body 53, which is rotationally fixed to the spindle 30, can still be held lifted from the second clamping cone body 54 or, if necessary, controlled, can be held in an intermediate position in which braking friction occurs but the clamping cone bodies 53, 54 do not yet jam.

[0041] To move the piston 22 in the second direction 32, i.e., in the retraction direction for the purpose of lowering the load 29 or even just for the purpose of retracting the piston 22, hydraulic fluid can be supplied via the first fluid channel 46, whereby hydraulic fluid can only be supplied to the second working channel subsequently or simultaneously. This allows the first clamping cone body 53, which is rotationally fixed to the spindle 30, to be moved or raised together with the threaded spindle 30 and the piston 22 in the first direction 31, again until the first clamping cone body 53 comes into contact with the rolling bearing 38, whereupon the spindle 30, together with the first clamping cone body 53, which is rotationally fixed to it, begins to rotate in the now opposite direction, whereupon the piston 22, together with the load 29, is moved in the second direction 32, i.e., in the retraction direction.The pressure medium located in the first working chamber 48 can then flow out via the first working channel.

[0042] During the movement of the piston 22 in the second direction 32, the first fluid channel 46 is constantly pressurized, so that the fluid sliding bearing 45 is constantly pressurized and at the same time the first clamping cone body 53, which is rotationally fixed to the spindle 30, is lifted from the second clamping cone body 54, which is rotationally fixed to the cylinder 21, into a lifting and unlocking position in which their locking cone surfaces 51, 52 do not touch, so that the first clamping cone body 53 and the spindle 30 can rotate, preferably substantially freely, about the spindle axis of rotation 33 relative to the cylinder 21.

[0043] If the fluid sliding bearing 45 is formed by pressurizing the first fluid channel 46 and the first clamping cone body 53 is lifted from the second clamping cone body 54 in such a way that their locking cone surfaces 51, 52 no longer touch, the pressure medium supplied to the recess 75 through the first fluid channel 46 can flow through an annular gap formed between the locking cone surfaces 51 and 52 of the clamping cone bodies 53 and 54 and subsequently through the second fluid channel.

[0044] To stop the piston 22 moving in the second direction 32, both the second working channel and the first fluid channel 46 can now be depressurized, so that, due to the acting load 29, the spindle 30 immediately moves together with the first clamping cone body 53 in the second direction 32, again only by the small spindle displacement play from here, preferably only about 1.0 to 1.5 mm, until the first clamping cone body 53 is self-lockingly clamped onto or in the second clamping cone body 54. Then the spindle 30 is locked against rotation about its axis of rotation 33 relative to the cylinder 21 by this self-locking clamping mechanism, as well as against axial lifting in the axial direction 59, i.e. also in the first direction 31, so that a double self-locking is achieved again.

[0045] In the locking cylinder 20, the clamping force between the clamping cone bodies 53 and 54, which are clamped together, increases proportionally with increasing load 29. This ensures that, under any load, the spindle 30 is always securely locked against rotation about its axis of rotation 33 relative to the cylinder 21. Consequently, further movement of the piston 22 and the load 29 acting on it is reliably prevented, not only during normal operation of the locking cylinder 20, but also in the event of a pressure failure in the hydraulic system or a leak in the hydraulic system.

[0046] It is understood that the locking cylinder 20 may be coupled or equipped with a device 84 for regulating and / or controlling the pressure medium in order to regulate and / or control its various operating states or functions.

[0047] According to the invention, an integrated rotary encoder 85, or rotary angle encoder, in particular an incremental encoder or incremental rotary encoder, is provided for detecting the change in the angle of rotation of the second threaded body, here the spindle 30, when it rotates about the axis of rotation 33 relative to the cylinder 21. This encoder enables the measurement of the piston travel or piston stroke that the piston 22 travels in the axial direction 59 relative to the cylinder 21 when the second threaded body 30 rotates about the axis of rotation 33. Several signals 86.1, 86.2, or pulses, proportional to the change in the angle of rotation of the second threaded body, here the spindle 30, can be generated by means of the rotary encoder 85 (see Figures 6.1 to 7.2The signals 86.1, 86.2, or pulses, are generated by the rotary encoder 85 during rotation of the second threaded body 30 about the axis of rotation 33. The signals 86.1, 86.2, or pulses generated by the rotary encoder 85 are proportional to the piston travel or piston stroke of the piston 22, which it travels in the axial direction 59 relative to the cylinder 21 during rotation of the second threaded body, here the spindle 30, about the axis of rotation 33. The rotary encoder 85 is an inductive and pressure-resistant sensor. The rotary encoder 85 (sensor) can also be referred to as an encoder. The rotary encoder 85 is detachably mounted in an outer wall 87 of the cylinder 21, preferably by screwing it in.

[0048] To detect the change in the angle of rotation of the second threaded body, here the spindle 30, by means of the rotary encoder 85, a rotary body 55 (timing disk) having an outer circumference 88 is provided, which is connected to the second threaded body, here the spindle 39, in a rotationally fixed, preferably rigid, manner. The rotary body 55 has a tooth profile 89 on its outer circumference 88, which extends in a circumferential direction (double arrow 90) around the axis of rotation 33. The tooth profile 89 serves to trigger the signals 86.1, 86.2 or pulses generated by the rotary encoder 85. The tooth profile 89 has a plurality of, for example, 12, 16, or 20, grooves 92. The grooves 92 are distributed around the outer circumference 88 of the rotating body 55, offset from each other in the circumferential direction 90 at equal circumferential angles 91 about the axis of rotation 33 of the rotating body 55 or the spindle 30. The grooves 92 extend in the axial direction 59 and are flanked by tooth flanks 93.1, 93.2 a corresponding number of teeth 94 of the groove walls forming the tooth profile 89. Each groove 92, viewed in the circumferential direction 90, has a uniform groove width 95 between its two associated groove walls 93.1, 93.2. In the illustrated embodiment, each groove 92 has a groove width 95 of 6.2 mm. In each groove 92, the opposing groove walls 93.1, 93.2 are parallel and substantially planar. Each groove 92 has a substantially planar groove base 96, which can also be referred to as the tooth root. The groove base 96 of each groove 92 is perpendicular to the associated groove walls 86.1, 86.2 of the respective groove 92. Preferably, all grooves 92 are produced by removing material, in particular by machining, preferably by milling. The rotary encoder 85 (sensor) is arranged in the outer wall 87 of the cylinder 21 opposite the tooth profile 89 of the rotating body 55 (timing disk).In the embodiment shown in the figures, 12 identical grooves 92 are rotationally symmetrical about the axis of rotation 33 and are machined onto the outer diameter of the rotating body 55. In the illustrated embodiment, the piston 22 has a piston diameter of 63 mm. Preferably, the spindle thread 28 of the spindle 30 has a spindle pitch of 32 mm. This ensures that every 32 mm of stroke or travel that the piston 22 travels during a rotation of the spindle 30 about its axis of rotation 33 in the axial direction 59 completes one full revolution of the spindle 30, so that the spindle 30 has then rotated 360 degrees about the axis of rotation 33. When using the pressure-resistant inductive sensor 85 with a size M8x1, an accuracy of 1 mm can be achieved when measuring the piston travel or piston stroke, which the piston 22 travels in the axial direction 59 when the spindle 30 rotates about the axis of rotation. A pressure-resistant rotary encoder or...Sensor 85 is necessary in the present case because the chamber or space 75, with which the rotary encoder or sensor 85 is directly connected, is subjected to hydraulic pressure during the operation of the locking cylinder 20.

[0049] The invention also relates to a method for measuring the piston travel or piston stroke of the piston 22 of the locking cylinder 20, in which a change in the angle of rotation of the second threaded body, here the spindle 30, is detected by means of the rotary encoder 85 during the rotation of the second threaded body, here the spindle 30, about the axis of rotation 33 relative to the cylinder 21. During the rotation of the second threaded body or the spindle 30 about the axis of rotation 33, several signals 86.1, 86.2 or pulses proportional to the change in the angle of rotation of the second threaded body or the spindle 30 are generated by means of the rotary encoder 85, which are proportional to the piston travel or piston stroke of the piston 22 that it travels in the axial direction 59 relative to the cylinder 21 during the rotation of the second threaded body or the spindle 30 about the axis of rotation 33. This enables an integrated measurement of the piston travel or piston stroke.The piston stroke of piston 22 enables or facilitates an integrated measurement of the piston travel or stroke that the piston 22 travels during a rotation of the second threaded body or spindle 30 about the axis of rotation 33, in the axial direction 59 relative to the cylinder 21. The signals 86.1, 86.2 generated by the rotary encoder 85 can be evaluated (decoded) by means of a signal evaluation device (decoder) not shown in the figures. In particular, it is provided that the signal evaluation device coupled to the rotary encoder 85 is used to determine the piston travel or stroke that the piston 20 travels during a rotation of the second threaded body or spindle 30 about the axis of rotation 33 relative to the cylinder 21, in the axial direction 59 relative to the cylinder 21.

[0050] The signals 86.1, 86.2 generated by the rotary encoder (sensor) 85 are incremental signals. These are designed such that a trapezoidal or rectangular signal waveform is obtained over time (see Figures 6.1 to 7.2). To detect the change in the angle of rotation and consequently the piston travel or stroke of the piston 22 during the rotation of the second threaded body or the spindle 30 about the axis of rotation 33, a temporal sequence of signals 86.1, 86.2 is generated by the rotary encoder 85. In this process, a signal 100.1, 101.1 that increases over time 103 is followed by a signal 100.2, 101.2 that decreases over time 103, and a signal 100.2, 101.2 that decreases over time 103 is followed by a signal 100.1, 101.1 that increases over time 103 (see Figures 6.1 to 7.2). Each rising signal 100.1, 101.1 and each immediately following falling signal 100.2; 101.2 each have a first signal spacing of 97.1; 98.1 from each other. Each falling signal 100.2, 101.2 and each immediately following rising signal 100.1, 101.1 each have a second signal spacing of 97.2; 98.2 from each other. In the Figures 6.1 and 6.2In the first example of a signal diagram or signal curve 99.1 shown, in which the signal strength 102 is plotted against time 103, the first signal interval 97.1 and the second signal interval 97.2 are equal. In other words, the first signal interval 97.1 from a rising edge to a falling edge is equal to the second signal interval 97.2 from a falling edge to a rising edge. This results when, as in the illustrated embodiment, all grooves 92 are identical and arranged such that they are offset from each other in the circumferential direction 90 by the same circumferential angle 91 about the axis of rotation 33 and each has the same groove width 95.It necessarily follows that the teeth 94 of the rotating body 85 are also arranged such that they are offset from each other by the same circumferential angle about the axis of rotation 33 and each has the same tooth width. In the embodiment shown in the figures, the respective circumferential angle by which the teeth 94 are offset from each other in the circumferential direction 90 about the axis of rotation is not exactly the same as the respective circumferential angle 91 by which the grooves 92 are offset from each other in the circumferential direction 90 about the axis of rotation 33. Furthermore, the respective tooth width of the teeth 94 is not exactly the same as the respective usable width 95 of the grooves 92 (see in particular...). Figure 5.2Due to the measures described above, both signals 100.1 and 100.2, rising and falling edges, can be evaluated (counted) as an incremental signal, resulting in twice the accuracy compared to when only the falling edges or only the rising edges are detected by a rotary encoder or sensor. For this to work, it would suffice that the slots or teeth of a similar rotating body are arranged circumferentially at equal circumferential angles around the axis of rotation of the rotating body or spindle. In this latter case, the distance between the slots and teeth is, simply put, limited only to the point where only one signal from the rotary encoder or sensor 85, with both rising and falling edges, is present.

[0051] In the Figures 7.1 and 7.2A second example of a signal diagram 99.2, or signal curve, is shown, in which the signal strength 102 is plotted against time 103. This second example illustrates an alternative embodiment in which the teeth of a similar body of revolution are narrower, i.e., have a smaller tooth width in the circumferential direction than those in the Figures 1 to 5.4 shown teeth 94 and in which the grooves of the rotating body are wider, i.e., have a greater groove width in the circumferential direction than those in the Figures 1 to 5.4 shown grooves 92. In this second example, the falling edges as well as the rising edges of the signals 86.2 are detected by means of the rotary encoder or sensor 85.

[0052] It goes without saying that signal generation methods other than those using slots and teeth in combination with an inductive rotary encoder or sensor, or other rotary encoders or sensors, would also be possible. For example, a coded magnetic ring could be used for signal generation, or a type of barcode that is optically detected. However, such rotary encoders or sensors are currently not pressure-resistant. It would, however, be possible to use such non-pressure-resistant rotary encoders or sensors in a sealed area, as already mentioned above as an example.

[0053] The invention can also be summarized as follows: The invention relates to a locking cylinder 20 comprising a cylinder 21 extending in the direction of a cylinder longitudinal axis 25 and a piston 22, which is movable in an axial direction 59 parallel to the cylinder longitudinal axis 25 relative to the cylinder 21 by means of a fluid pressure medium, but is rotationally fixed to the cylinder 21. The piston 22 is rotationally fixed to a first threaded body 24, the first thread 26 of which engages with a second thread 28 of a frictionally and automatically lockable second threaded body 30, forming a non-self-locking thread 27. The second threaded body 30 is rotatable about an axis of rotation 33 extending parallel to the cylinder longitudinal axis 25 of the cylinder 21 and is axially movable in the axial direction 59.According to the invention, an integrated rotary encoder 85 is provided for detecting a change in the angle of rotation of the second threaded body 30 when it rotates about the axis of rotation 33 relative to the cylinder 21, by means of which it is possible to measure a piston travel that the piston 22 travels when the second threaded body 30 rotates about the axis of rotation 33 in the axial direction 59 relative to the cylinder 21. Reference symbol list

[0054] 20 Locking cylinder 21 Cylinder 22 Piston 22.1 Piston rod 23.1 (First) side / Piston side 23.2 (Second) side / Piston side 24 (First) Threaded body / Nut 25 Longitudinal axis / Cylinder longitudinal axis 26 (First) Thread / Piston thread 27 Non-self-locking thread 28 (Second) Thread / Spindle thread 29 Load (arrow) 30 (Second) Threaded body / Spindle 31 First direction 32 Second direction 33 Axis of rotation of 30 34 Double arrow / Axial displacement / Displacement clearance / Axial spindle play 35 (First) Locking support body 36 (Second) Locking support body 37 Seal / Ring seal 38 (First) Thrust bearing / Roller bearing / Needle bearing / Ring bearing 39 (Second) Axial bearing / Fluid plain bearing 40 Cylinder base 40.1 (Cylinder) cover 41 (First) bearing body 42 (Second) bearing body 43 (First) bearing surface 44 (Second) bearing surface 45 Fluid plain bearing 46 (First) fluid channel 47.1 (First) spherical bearing 47.2 (second) spherical bearing 48 (first) working chamber 49 (second) working chamber 50 threadless part of 30 51 (first) locking cone surface(s) 52 (second) locking cone surface(s) 53 (first) clamping cone body 54 (second) clamping cone body 55 rotating body / cone bushing / timing disc / cone washer / cone stub washer 56 external cone 57 internal cone 58 part of 53 59 axial direction (double arrow) 61 (first) locking support and bearing body 62 (second) locking support and bearing body 63 (first) angle of inclination 64 (second) angle of inclination 65 (first) side of 53 66 (second) Page of 53 67 (first) Page of 54 69 (cylinder bottom end) End of 30 71 (free) End of 30 72 Approach 75 Recess / chamber / space 76 Seal 80 Outer diameter of 43 81 Inner diameter of 76 82 Outer diameter of 50 83 Side of 76 84 Device for control and / or regulation 85 Rotary encoder / Angle encoder / Incremental encoder / Incremental rotary encoder / Sensor 86.1 Signal / pulse 86.2 Signal / Impulse 87 Outer wall of 21 88 Outer circumference of 21 89 Tooth profile / Gear profile 90 Circumferential direction (double arrow) 91 Circumferential angle 92 Groove 93.1 (first) Tooth flank / Groove wall 93.2 (second) Tooth flank / Groove wall 94 Tooth 95 Groove width 96 Groove root 97.1 (first) Signal spacing 97.2 (second) Signal spacing 98.1 (first) Signal spacing 98.2 (second) Signal spacing 99.1 Signal diagram / Signal curve 99.2 Signal diagram / Signal curve.

Claims

1. Locking cylinder (20) comprising a cylinder (21) extending in the direction of a cylinder longitudinal axis (25) and a piston (22) comprising a first piston side (23.1) and a second piston side (23.2) pointing away from it, and which is connected by means of one of the first piston side (23.1) or the second piston side (23.2) or the first piston side (23.1) and the second piston side (23.2) a supplyable fluid pressure medium in an axial direction (59) parallel to the longitudinal axis (25) of the cylinder relative to the cylinder (21), but rotationally fixed to the cylinder (21), wherein the piston (22) is rotationally fixed to a first threaded body (nut or spindle) (24), the first thread (nut thread or spindle thread) (26) of which engages with a second thread (spindle thread or nut thread) (28) of a frictionally and automatically lockable second threaded body (spindle or nut) (30) forming a non-self-locking thread (27), and wherein the second threaded body (spindle or nut) (30) is rotatable about an axis of rotation (33) extending parallel to the longitudinal axis (25) of the cylinder (21) relative to the cylinder (21) and axially movable relative to the cylinder (21) in the axial direction (59). is movable. characterized by thatan integrated rotary encoder (85) is provided for detecting a change in the angle of rotation of the second threaded body (spindle or nut) (30) when it is rotated about the axis of rotation (33) relative to the cylinder (21), by means of which it is possible to measure a piston travel that the piston (22) travels when the second threaded body (spindle or nut) (30) is rotated about the axis of rotation (33) in the axial direction (59) relative to the cylinder (21).

2. Locking cylinder according to claim 1 characterized by the fact that by means of the rotary encoder (85) several signals (86.1, 86.2) proportional to the change in the angle of rotation of the second threaded body (spindle or nut) (30) can be generated or are generated, which are proportional to the piston travel of the piston (22) which it travels when the second threaded body (spindle or nut) (30) is rotated about the axis of rotation (33) in the axial direction (59).

3. Locking cylinder according to claim 1 or 2, characterized by the fact thatTo detect the change in the angle of rotation of the second threaded body (spindle or nut) (30) by means of the rotary encoder (85), a rotating body (85) having an outer circumference (88) is provided, which is non-rotatably connected to the second threaded body (spindle or nut) (30) and which has a tooth profile (89) on its outer circumference (88) extending in a circumferential direction (90) around the axis of rotation (33), for triggering the signals (86.1, 86.2) generated by means of the rotary encoder (85).

4. Locking cylinder according to claim 3 characterized by the fact that the tooth profile (89) is provided with a plurality of grooves (92) arranged over the outer circumference (88) of the rotating body (85) in the circumferential direction (90) at equal circumferential angles (91) to each other about the axis of rotation (33), which extend in the axial direction (59) and which are bounded by tooth flanks of teeth (94) of the tooth profile (89) groove walls (93.1, 93.2).

5. Locking cylinder according to claim 4 characterized by the fact that Each groove (92) of the grooves (92), viewed in the circumferential direction (90), has the same groove width (95) between the groove walls (93.1, 93.2) associated with it.

6. Locking cylinder according to claim 4 or 5, characterized by the fact that the opposing groove walls (93.1, 93.2) of each groove (92) are formed parallel to each other.

7. Locking cylinder according to claim 1 characterized by the fact that Each groove (92) has a substantially planar groove base (96) which is formed perpendicular to the associated groove walls (93.1, 93.2).

8. Locking cylinder according to one of claims 4 to 7, characterized by the fact that Each groove (92) is produced by removing material from the rotating body (55).

9. Locking cylinder according to one of the preceding claims, characterized by the fact that The rotary encoder (85) is an inductive and / or pressure-resistant sensor.

10. Locking cylinder according to one of claims 3 to 9, characterized by the fact thatthe rotary encoder (85) is attached in an outer wall (87) of the cylinder (21) opposite the tooth profile (89).

11. Method for measuring the piston travel of the piston (22) of the locking cylinder (20) according to one of the preceding claims, characterized by that by means of the rotary encoder (85) during the rotation of the second threaded body (spindle or nut) (30) about the axis of rotation (33) relative to the cylinder (21) the change in the angle of rotation of the second threaded body (spindle or nut) (30) is detected.

12. Method according to claim 11, characterized by the fact thatBy means of the rotary encoder (85) during the rotation of the second threaded body (spindle or nut) (30) about the axis of rotation (33) several signals (86.1, 86.2) proportional to the change in the angle of rotation of the second threaded body (spindle or nut) (30) are generated, which are proportional to the piston travel of the piston (22) which it travels in the axial direction (59) during the rotation of the second threaded body (spindle or nut) (30) about the axis of rotation (33), so that a measurement of the piston travel is made possible or is carried out, which the piston (22) travels when the second threaded body (spindle or nut) (30) is rotated about the axis of rotation (33) in the axial direction (59).

13. Method according to claim 11 or 12, characterized by the fact thatThe piston travel distance traveled by the piston (22) during a rotation of the second threaded body (spindle or nut) (30) about the axis of rotation (33) relative to the cylinder (21) in the axial direction (59) is determined by means of a signal evaluation device coupled to the rotary encoder (85) for evaluating the signals (86.1, 86.2) generated by the rotary encoder (85).

14. Method according to any one of claims 11 to 13, characterized by the fact thatThe signals (86.1, 86.2) of the rotary encoder (85) are incremental signals (86.1, 86.2) designed such that a trapezoidal or rectangular signal profile results over time, whereby a temporal sequence of signals (86.1, 86.2) is generated by the rotary encoder (85) to detect the change in the angle of rotation and consequently the piston travel during the rotation of the second threaded body (spindle or nut) (30) about the axis of rotation (33), in which a signal increasing over time (100.1; 101.1) is followed by a signal decreasing over time (100.2; 101.2) and in which a signal decreasing over time (100.2; 101.2) is followed by a signal increasing over time (100.1; 101.2). follows, wherein each rising signal (100.1; 101.1) and the immediately following falling signal (100.2; 101.2) have a first signal interval (97.1; 98.1) to each other, and wherein each falling signal (100.2; 101.2) and the immediately following rising signal (100.1; 101.1) have a second signal spacing (97.2; 98.2) to each other that is the same as the first signal spacing (97.1; 98.1).

Images