micrometer

Abstract

Micrometer screw (10) having: - a basic body (11), - a measuring pin (19) mounted so as to be linearly movable in a longitudinal direction (L) along a longitudinal axis (A) relative to the base body (11), - comprising a spindle unit (24) rotatably mounted about the longitudinal axis (A), a spindle (23) extending along the longitudinal axis (A), and an operating sleeve (26) enclosing the longitudinal axis (A), wherein the spindle (23) is coupled to the measuring pin (19) by means of a first coupling device (22), - a preloading device (40) configured to generate a longitudinally directed (L) preload force (F) between the spindle unit (24) and the base body (11), - an actuating ring (45) rotatably mounted about the longitudinal axis (A), which is coupled to the spindle unit (24) in the longitudinal direction (L) and which is coupled to the base body (11) by means of a second coupling device (47) such that a rotation of the actuating ring (45) causes a displacement of the spindle unit (24) and the measuring pin (19) in the longitudinal direction (L) relative to the base body (11) against the preload force (F) of the preload device (40).

Description

[0001] The invention relates to a micrometer, in particular a micrometer with a hand-held caliper. The micrometer is specifically designed to be held and operated with one hand. It can, for example, have a measuring range of up to 50 mm.

[0002] The micrometer has a preferably digital display for outputting a sensor-detected measurement value. The measurement value can be detected by a measuring device, particularly without contact, for example electrically and / or electronically and / or optically and / or inductively. The micrometer can also be referred to as a digital micrometer.

[0003] To measure a dimension of a workpiece, it is placed between a contact surface and a linearly movable measuring pin. The measuring pin is then moved against the workpiece using a rotatable operating sleeve, so that the side of the measuring pin opposite the contact surface rests against the workpiece. The measured value can then be read on a display.

[0004] To repeatedly measure identical workpieces, micrometers are known in which an additional operating device can be used to stroke the measuring pin, allowing the measured workpiece to be removed and a new one inserted. This eliminates the need for additional actuation of the rotating operating sleeve, enabling the rapid measurement of several identical workpieces in succession.

[0005] Such a micrometer screw is known, for example, from DE 295 03 339 U1. The measuring pin is connected to a spindle for movement, which can be rotated by means of the operating sleeve. The spindle is mounted in a housing via a rotary bearing. By means of a release lever, the rotary bearing, together with the measuring spindle and the measuring pin, can be moved against the force of a spring.

[0006] To achieve sufficient stroke of the micrometer's measuring pin with such a lifting lever, depending on the effective lever length, either high forces must be applied manually (especially with the thumb) to the lifting lever, or the lever must travel a long distance. The spring force cannot be reduced arbitrarily, as this would impair the measuring accuracy.

[0007] DE 10 2009 002 649 B4 discloses a gear measuring device with two measuring rollers that can be inserted into a gear tooth. The distance between the measuring rollers indicates the measured value. A support rod, on which one of the measuring rollers is arranged, can be linearly displaced by means of a pivotably mounted lifting lever.

[0008] DE 10 2015 224 902 A1 describes a micrometer with a locking device. The locking device can be switched between a locking position and a release position by means of a sliding wedge knob. The locking device has a gear whose teeth engage with external teeth on a rotatable spindle. The rotatable spindle is coupled to a measuring pin of the micrometer. The spindle can be rotated by turning an operating sleeve, thereby moving the measuring pin. In the release position of the locking device, the gear engaging with the external teeth of the spindle is freely rotatable, so that movement of the spindle and the measuring pin along the axis of rotation is permitted. In this way, rapid adjustment of the measuring pin is possible.

[0009] The measuring instrument known from DE 10 2015 208 403 B4 has a measuring pin and a contact surface on an anvil, whereby the dimension of a workpiece can be measured between the measuring pin and the contact surface. The anvil can be moved away from the measuring pin by means of a device. The device has a pivotally mounted lever, the pivoting movement of which causes a displacement of the anvil. A control button located at one end of the lever can be pressed to initiate the pivoting movement.

[0010] A micrometer with manually adjustable measuring force is described in DE 101 36 360 B4. The set measuring force is displayed, so that workpieces can be measured under a constant measuring force whenever possible.

[0011] DE 43 31 768 A discloses an electronic linear yoke micrometer having a quill which can be moved freely by hand in the entire measuring space when the quill is unlocked by means of an operating button.

[0012] The micrometer screw known from US patent 4,389,783 has a slider that can be moved linearly forwards and backwards and locked in any position relative to a frame of the micrometer screw. A measuring force on an object to be measured can be set independently of the slider's position.

[0013] From US 2 810 201 A a micrometer screw is known in which the micrometer spindle can be retracted by means of an operating lever to enable a simpler arrangement of the micrometer screw on an object to be measured.

[0014] The micrometer measuring instrument known from JP S54-130 152 A features a rotating control knob for linearly moving a measuring spindle. Length measurement is performed using an optoelectronic measuring device.

[0015] JP S56-72 301 A discloses a micrometer measuring device in which a measuring spindle, upon contact with an object to be measured, transmits a force via a spring to a slide. The spring serves to set a defined measuring force, whereby further slide movement is prevented once the measuring force is reached.

[0016] Based on the prior art, the object of the present invention can be considered to be to create a measuring screw whose operation has improved ergonomics.

[0017] This problem is solved by a micrometer screw with the features of claim 1.

[0018] The micrometer according to the invention has a base body. The base body can be part of a housing. A yoke with a contact surface for a workpiece can be provided on the base body if the micrometer is designed as a yoke micrometer. The base body can be sleeve-shaped at least in one section, the sleeve-shaped section preferably enclosing a longitudinal axis, in particular coaxially. The direction parallel to the longitudinal axis is referred to as the longitudinal direction.

[0019] A measuring pin is mounted for linear movement in the longitudinal direction. A spindle unit is rotatably arranged about the longitudinal axis and comprises a spindle extending along the longitudinal axis and an operating sleeve enclosing the longitudinal axis. The operating sleeve is, in particular, arranged coaxially with the longitudinal axis. The spindle is coupled to the measuring pin by means of a first coupling device. The first coupling device can, for example, be a threaded connection. In particular, the first coupling device causes a linear movement of the measuring pin when the spindle rotates about the longitudinal axis. Depending on the direction of rotation of the spindle, the measuring pin moves either towards a contact surface opposite it (extension movement) or away from the contact surface (retraction movement).

[0020] The spindle unit is mounted to be linearly movable relative to the base body, for example by means of a sliding bearing between the spindle unit and the base body.

[0021] The micrometer screw also has a preloading device. This device is designed to generate a preload force between the spindle unit and the base body. The preload force is understood to be a force component of the preloading device that is oriented in the longitudinal direction. Force components perpendicular to the longitudinal axis can optionally be generated by the preloading device in addition to the longitudinally acting preload force, but these are not required.

[0022] An actuating ring of the micrometer screw surrounds the longitudinal axis, in particular coaxially, and is rotatably mounted about the longitudinal axis. The actuating ring is longitudinally coupled to the spindle unit such that a rotation or screw movement of the actuating ring causes a longitudinal movement of the spindle unit. In particular, the actuating ring can be supported indirectly or directly on the spindle unit in the longitudinal direction (e.g., on the operating sleeve of the spindle unit). The actuating ring is coupled to the base body by means of a second coupling device. A rotation of the actuating ring causes a longitudinal displacement of the spindle unit and the measuring pin relative to the base body against the preload force of the preload device.

[0023] The actuating ring can be rotatably arranged and fixed in the longitudinal direction relative to the base body. In a preferred embodiment, the second coupling device causes a rotation of the actuating ring about its longitudinal axis to result in a further linear movement of the actuating ring in the longitudinal direction relative to the base body. This rotation about the longitudinal axis, combined with the linear movement in the longitudinal direction, allows the actuating ring to be moved between a starting position and an actuating position.

[0024] Due to the coupling of the actuating ring's movement with the spindle unit (e.g., operating sleeve), the rotation or helical movement of the actuating ring, in turn, causes a linear movement of the spindle unit in the longitudinal direction, counteracting the preload force of the preloading device. The spindle unit is in a rest position when the actuating ring is in its initial position. The spindle unit is in a position offset longitudinally from its rest position (which can be described as the lifting or actuation position) when the actuating ring is in an actuated position outside its initial position. Moving the spindle unit also moves the measuring pin longitudinally. In the rest position of the spindle unit, the distance of the measuring pin to the contact surface is smaller than in the offset position of the spindle unit.

[0025] When the spindle unit is moved from the rest position to the offset position, the measuring pin retracts. The measuring pin extends when the spindle unit is moved from the offset position to the rest position. The preload force generated by the preloading device preferably forces the spindle unit into the rest position.

[0026] The rotatably mounted actuating ring allows for ergonomic operation, for example, using the thumb and / or forefinger of an operator. In one embodiment, it can have radially outwardly projecting operating cams or protrusions, on which a finger can be ergonomically positioned. This improves force transmission in the circumferential direction around the longitudinal axis. The second coupling device can, for example, operate like a bayonet fitting. Converting the rotary motion of the actuating ring into a linear movement in the longitudinal direction enables precise coordination between the applied force or torque and the stroke or linear path of movement that the actuating ring, the spindle unit, and the measuring pin are to execute.By using such an actuation mechanism to perform a lifting movement of the measuring pin, very good ergonomics of the micrometer can be achieved, especially for micrometers that are operated with one hand by a single operator.

[0027] The micrometer preferably has a measuring device for acquiring a measured value and, in particular, for acquiring the longitudinal position of the measuring pin. The measuring device can comprise a sensor arranged on the base body and a scale arranged on the measuring pin. The sensor is configured to detect the position and / or change in position of the scale in the longitudinal direction relative to the sensor. The sensor preferably operates without contact with the scale, for example, inductively, capacitively, or optically.

[0028] It is preferred that the first coupling device is designed such that a rotation of the spindle causes a linear movement of the measuring pin along the longitudinal axis. The spindle, and preferably the entire spindle unit, does not move longitudinally relative to the base body. The measuring pin is secured against rotation about the longitudinal axis relative to the base body, in particular by means of an anti-rotation device.

[0029] In one embodiment, an axial bearing can be provided between the actuating ring and the operating sleeve. Viewed longitudinally, the actuating ring and the operating sleeve rest against the axial bearing from opposite sides. Alternatively, the actuating ring and the operating sleeve can also rest directly against each other longitudinally. Optionally, the actuating ring can also be coupled longitudinally to any other component of the spindle unit, so that a longitudinal movement of the actuating ring results in a corresponding movement of the spindle unit.

[0030] The rotational angular range within which the actuating ring can be rotated about the longitudinal axis can preferably be limited, in particular to a rotational angular range of less than 360°. In a preferred embodiment, the rotational angular range is limited to 90° or less, for example to a maximum of 60° to 90°.

[0031] The spindle unit can be rotatably mounted on the base body, for example, by means of a plain bearing. Alternatively, the spindle unit can be rotatably mounted on the base body by means of a rotary bearing, and in particular a rolling bearing. Using a rolling bearing reduces the torque required for rotation compared to using a plain bearing. The plain bearing has the advantage of a simple design.

[0032] The rotary bearing and the spindle unit can be coupled in the longitudinal direction and, in particular, rigidly connected to each other in the longitudinal direction. The rotary bearing and the spindle unit can thus form an assembly that is linearly movable in the longitudinal direction. For this purpose, the rotary bearing can be arranged to be linearly movable in the longitudinal direction on the base body, for example by means of a plain bearing.

[0033] The first coupling device and the second coupling device preferably provide different gear ratios or coupling ratios. The first coupling device, for example, has a first coupling ratio defined as the length of the linear movement of the measuring pin in the longitudinal direction divided by the number of spindle revolutions required for this linear movement of the measuring pin in the longitudinal direction. The second coupling device has a second coupling ratio defined as the length of the linear movement of the measuring pin in the longitudinal direction divided by the number of revolutions of the actuating ring required for this linear movement of the measuring pin in the longitudinal direction. The two coupling ratios are particularly different in magnitude, and preferably the first coupling ratio is smaller than the second coupling ratio.

[0034] For example, the first coupling ratio can be less than 1 mm per revolution (360°). The second coupling ratio can preferably be greater than 10 mm per revolution (360°). For example, the second coupling ratio can be 15 mm to 20 mm per revolution (360°). The rotation angle range can be limited, as explained above, whereby the second coupling ratio, when utilizing the available rotation angle range (in particular 60° to 90°), allows, for example, a longitudinal movement of 2 mm to 4 mm (e.g., 3 mm longitudinal movement for a 60° rotation).

[0035] In particular, the first coupling device is designed to be self-locking. The first coupling device can, for example, be implemented as a threaded coupling or threaded connection. In one embodiment, the spindle has an external thread that engages with an internal thread of the measuring pin. Alternatively, the spindle can have the internal thread and the measuring pin the external thread.

[0036] It is advantageous if the second coupling device is designed to be non-self-locking. This allows it to return to its initial position by means of the preload force. If an operator moves the actuating ring from its initial position by applying a torque, the preload force will return the actuating ring to its initial position when the operator reduces or removes the torque. Due to the non-self-locking design of the second coupling device, a restoring torque is thus generated on the actuating ring, which is transmitted to the actuating ring via the second coupling device and the preload force of the preload device.

[0037] The starting position of the actuating ring can be defined by a stop on the base body against which the spindle unit and / or the actuating ring indirectly or directly rest when the actuating ring assumes the starting position.

[0038] In the preferred embodiment, the second coupling device has a guide track and a guide body movably arranged relative to the guide track. The guide track can be arranged on the actuating ring and the guide body on the base body, or vice versa. Multiple pairs, each consisting of a guide track and a guide body, can also be present, for example, two pairs. The guide track extends circumferentially around the longitudinal axis and is inclined at least in sections with a non-zero slope relative to the longitudinal direction. For example, the guide track can extend along a section of a helix or helical path around the longitudinal axis.

[0039] The guide track and the guide body operate together, for example, in the manner of a bayonet fitting. The guide track preferably extends only partially around the longitudinal axis, for example, within a rotational angle range of a maximum of 360°, 270°, or 180°.

[0040] In one embodiment, the guide track can be designed as a guide groove into which the guide body engages. The guide track preferably has at least one longitudinally extending surface, for example, a groove flank.

[0041] Advantageous embodiments of the invention will become apparent from the dependent claims, the description, and the drawing. Preferred embodiments of the invention are explained in detail below with reference to the accompanying drawing. The drawing shows: Fig. 1 an embodiment of a micrometer in the form of a micrometer with a hand-held caliper, Fig. 2 the micrometer screw Fig. 1 in a longitudinal section view along a longitudinal axis of the micrometer screw (section line II-II in Fig. 1) Fig. 3 A view of an embodiment of a micrometer screw looking in a longitudinal direction parallel to the longitudinal axis of the micrometer screw, Fig. 4 a perspective view of an embodiment of an actuating ring of the micrometer screw from the Fig. 1 to 3, Fig. 5 a block diagram-like schematic representation of an embodiment of the micrometer screw with an actuating ring in a starting position and a spindle unit in a rest position, and Fig. 6 the representation of the micrometer screw according to Fig. 5, wherein the actuating ring is in an actuating position and the spindle unit is in a position offset longitudinally from the rest position.

[0042] In the Fig. Figures 1 to 3 show an embodiment of a micrometer 10. The micrometer 10 has a base body 11. The base body 11 can comprise several parts. For example, the base body can include a housing part or several housing parts. In this embodiment, the base body 11 has a sleeve-shaped part, which is referred to here as the base sleeve 12. The base sleeve 12 coaxially surrounds a longitudinal axis A. The direction parallel to the longitudinal axis A is referred to as the longitudinal direction L.

[0043] The base body 11 also has a bracket 13 on which an anvil 14 is arranged. The anvil 14 has a contact surface 15, which is oriented perpendicular to the longitudinal direction L. The contact surface 15 is penetrated by the longitudinal axis A, preferably in the center. In this embodiment, the contact surface 15 is circular.

[0044] A measuring pin 19 is mounted on the base body 11 so as to be linearly movable in the longitudinal direction L, for example by means of a sliding bearing arrangement. In the exemplary embodiment, two sliding bearing points are provided. For example, a sliding bearing 20 for the measuring pin 19 can be provided on a housing part of the base body 11. As shown in Fig. As can be seen in Figure 2, the measuring pin 19 is guided slidably in the base sleeve 12 with an end section 21.

[0045] The end section 21 is connected to a spindle 23 of a spindle unit 24 by means of a first coupling device 22, thus being drive-connected. The spindle unit 24 is rotatably mounted about the longitudinal axis A on the base body 11. For this purpose, the spindle 23 can, for example, be supported on the inside of the base sleeve 12 by means of a rotary bearing 25, preferably a rolling bearing.

[0046] The spindle 23 of the spindle unit 24 extends along the longitudinal axis A and, for example, within the base sleeve 12. The spindle 23 is rotationally fixed to an operating sleeve 26 of the spindle unit 24 by means of a connecting device 27. The operating sleeve 26 is arranged coaxially to the longitudinal axis A and, in the exemplary embodiment, encloses at least a longitudinal section of the base sleeve 12.

[0047] The operating sleeve 26 has an operating surface pointing away from the longitudinal axis A, which is designed for rotation of the operating sleeve 26 by an operator. The operating surface of the operating sleeve 26 can, for example, have a knurled or serrated surface to improve operability by hand for rotating the operating sleeve 26 about the longitudinal axis A.

[0048] In the exemplary embodiment, the connecting device 27 is configured to create a rotationally fixed connection between the operating sleeve 26 and the spindle 23. For example, the operating sleeve 26 is connected to the spindle 23 by means of a connecting pin 29. The operating sleeve 26, the connecting pin 29, the spindle 23, and optionally also the rotary bearing 25 can form a single rotatable assembly. The rotary bearing 25 can, for example, alternatively be rotationally fixed to the base body 11, whereby the rotary bearing 25 is displaceable in the longitudinal direction L relative to the base body 11.

[0049] The in Fig. The connecting device 27 shown in Figure 2 is merely an exemplary embodiment. The rotationally fixed connection can also be achieved by other positive-locking and / or material-locking and / or force-locking connections. Positive-locking coupling in the circumferential direction around the longitudinal axis A provided by the connecting device 27 is preferred. In particular, the connecting device 27 can establish a positive-locking, rotationally fixed coupling with both the operating sleeve 26 and the spindle 23.

[0050] Preferably, the first coupling device 22 is designed to be self-locking. A rotation of the spindle 23 can cause movement of the measuring pin 19 in the longitudinal direction L; conversely, a force acting on the measuring pin 19 in the longitudinal direction cannot cause rotation of the spindle 23.

[0051] In the embodiment illustrated here, the first coupling device 22 is implemented by a threaded connection. For this purpose, the spindle 23 has an external thread 31 which engages with an internal thread 32 on the measuring pin 19. The internal thread 32 is present, in particular, in the end section 21 of the measuring pin 19. The end section 21 can be a spindle nut.

[0052] As it is in Fig. As can be seen in Figure 2, the measuring pin 19 is secured against rotation about the longitudinal axis A. For this purpose, in the exemplary embodiment, a locking projection 33 is provided in the end section 21, which engages in a longitudinal recess 34 on the base body 11 and, for example, the base sleeve 12. The longitudinal recess 34 can be a longitudinal groove, a longitudinal slot, or an elongated hole. The locking projection 33 can therefore move within the longitudinal recess 34 in the longitudinal direction L, but prevents rotation of the measuring pin 19 and, for example, its end section 21 about the longitudinal axis A. The locking projection 33 and the longitudinal recess 34 thus form an anti-rotation device.

[0053] Following the end section 21, the measuring pin 19 has a hollow cylindrical longitudinal section extending along the longitudinal axis A, forming a cavity 35. The cavity 35 is dimensioned radially to the longitudinal axis A such that the spindle 23 can move freely into the cavity 35. Rotation of the spindle 23 about the longitudinal axis A generates a linear movement of the measuring pin 19. During this movement, the end section 21 with the internal thread 32 moves longitudinally L along the external thread 31 of the spindle 23. An axial section of the spindle 23 then projects into the cavity 35 of the measuring pin 19.

[0054] The spindle unit 24 is mounted to be movable in the longitudinal direction L relative to the base body 11. In the exemplary embodiment, the rotary bearing 25 is arranged to slide in the base sleeve 12 in the longitudinal direction L. To block rotational movement of the rotary bearing 25 about the longitudinal axis A, it can have a locking projection 33, analogous to the measuring pin, which engages in a corresponding longitudinal recess 34 on the base body 11 and, for example, on the base sleeve 12. The two longitudinal recesses 34 for the locking projection 33 can be aligned with each other in the longitudinal direction L.

[0055] A preload force F is generated between the base body 11 and the spindle unit 24 by means of a preloading device 40. The preload force F is the force component that is generated in the longitudinal direction L between the base body 11 and the spindle unit 24. By means of the preload force F, the spindle unit 24 is forced into a rest position R ( Fig. 2 and Fig. 5).

[0056] In the Fig. 2, Fig. 5 and Fig. In the embodiment shown in Figure 6, the preload device 40 comprises a spring and, for example, a coil spring 41. A single coil spring 41 is sufficient. In addition to or as an alternative to a coil spring 41, at least one disc spring or at least one other elastically deformable body could also be used as the preload device 40. The preload force can also be generated in other ways, for example, as a magnetic force. For this purpose, for example, repelling magnets can be used.

[0057] In the exemplary embodiment, the helical spring 41 is arranged around the longitudinal axis A and, for example, surrounds at least a part of the connecting pin 29. The helical spring 41 is, for example, arranged inside the base sleeve 12 and is supported at one end via the rotary bearing 25 on the spindle unit 24 and at the other end indirectly or directly on the base sleeve 12. For this purpose, a support ring 42 (in particular a spring ring) can, for example, be arranged in an inner groove of the base sleeve 12.

[0058] As it is in Fig. As shown schematically in Figure 2, the preloading device 40 and, for example, the coil spring 41 exert a preload force F on the rotary bearing 25 and thus on the spindle unit connected to the rotary bearing 25, which forces the spindle unit 24 in the longitudinal direction L into the rest position R. The preload force F is, for example, a compressive force.

[0059] In addition to the operating sleeve 26, the micrometer screw 10 has an actuating ring 45 rotatably mounted coaxially with respect to the longitudinal axis A. In the exemplary embodiment, the actuating ring 45 is supported directly or indirectly by the spindle unit 24. The actuating ring 45 can be arranged adjacent to the operating sleeve 26 in the longitudinal direction L. An axial bearing 46 can be arranged between the actuating ring 45 and the operating sleeve 26, against which the actuating ring 45 and the operating sleeve 26 bear. The axial bearing 46 is preferably designed as a rolling bearing (e.g., a ball bearing). It allows relative rotation between the actuating ring 45 and the operating sleeve 26.

[0060] Ball bearings or roller bearings can be used as rolling bearings.

[0061] The actuating ring 45 is coupled to the base body 11 and, for example, the base sleeve 12 by means of a second coupling device 47. The coupling by means of the second coupling device 47 is designed such that a rotation of the actuating ring 45 about the longitudinal axis A produces a displacement of the actuating ring 45 in the longitudinal direction L relative to the base body 11 or the base sleeve 12. The actuating ring 45 thus performs a screw motion relative to the base body 11 or the base sleeve 12.

[0062] By way of example, the second coupling device 47 has at least one guide track 48 and a guide body 49 that is movable relative to and along the guide track 48. The guide track 48 can, for example, be a guide groove 50 into which the guide body 49 engages. In the exemplary embodiment, the guide track 48 or the guide groove 50 is located on the inner side of the actuating ring 45 facing the longitudinal axis A ( Fig. 2 and 4 to 6). On the base body 11 and, for example, the base sleeve 12, the guide body 49 is arranged immovably and rests against the guide track 48 or engages in the guide groove 50. In Fig. Figure 4 shows only a guide track 48 with an associated guide body 49. As shown in Fig. As can be seen in the longitudinal section 2, two or more pairs consisting of a guide track 48 and an associated guide body 49 can also be arranged circumferentially around the longitudinal axis A.

[0063] The at least one guide body 49 is, for example, arranged immovably on the base body 11 and, for example, on the base sleeve 12. Alternatively, the guide body 49 could be rotatable about its own axis relative to the base body 11 and arranged immovably on the base body 11 in the longitudinal direction L, thereby reducing frictional forces. In the exemplary embodiment, the at least one guide body 49 projects radially outwards from the longitudinal axis A into the respective guide groove 50 on the actuating ring 45.

[0064] In a variation of the illustrated embodiment, the guide track 48 could be arranged on the base body 11 and the guide body 49 on the actuating ring 45.

[0065] In this embodiment, the guide track 48 or the guide groove 50 extends along a section of a helical path that is arranged coaxially to the longitudinal axis A. The pitch of the guide track 48 or the guide groove 50 is constant, but in a modified embodiment, it can also assume different values ​​along its length.

[0066] The guide track 48 is preferably limited to a rotation angle range about the longitudinal axis A that is less than 360° and preferably a maximum of 270° or a maximum of 180°. In the embodiment illustrated here, a guide stop 51 for the associated guide body 49 is provided at least at one end of the guide track 48 or the guide groove 50, by means of which a maximum possible rotation angle range for rotating the actuating ring 45 about the longitudinal axis A can be limited. In the embodiment, the guide stop 51 is formed at an inner end of the groove by a wall section that connects the two groove flanks of the guide groove 50. At the end opposite the guide stop 51, the guide groove 50 can be open, as shown in Fig. 4 can be seen.

[0067] The first coupling device 22 has a first coupling ratio and the second coupling device 47 has a second coupling ratio, which differ from each other. The first coupling ratio is defined as the length of a linear movement of the measuring pin 19 in the longitudinal direction L divided by the number of revolutions of the spindle 23 performed during this movement. Analogously, the second coupling ratio is defined as the length of the linear movement of the measuring pin 19 in the longitudinal direction L divided by the number of revolutions of the actuating ring 45 performed during this movement. The first coupling ratio is, for example, smaller than the second coupling ratio.

[0068] The second coupling ratio can, for example, be in the range of 15 mm to 20 mm per revolution (360°). The rotation angle range can be limited, whereby, when utilizing the available rotation angle range (in particular 60° to 90°), the second coupling ratio allows, for example, a longitudinal movement of approximately 3 mm for a 60° rotation.

[0069] The first coupling ratio can be less than 1 mm per revolution (360°).

[0070] The actuating ring 45 can have at least one, and in the exemplary embodiment two, actuating projections 52 on its outer side facing away from the longitudinal axis A ( Fig. 3 and Fig. 4) On the actuating projections 52, the actuating ring has actuating surfaces 53 extending obliquely to the circumferential direction, which improve gripping with the fingers of one hand, in particular the thumb and / or index finger. As shown in Fig. As can be seen in Figure 4, knurling, ridges, or similar features may be present in the area of ​​the actuating surfaces 53 to further improve grip. In the embodiment illustrated here, the actuating projections 52 have a cam-like shape. Viewed circumferentially around the longitudinal axis A, each actuating projection 52 has a high point (area with maximum distance to the longitudinal axis A), to which an actuating surface 53 adjoins on opposite sides.

[0071] The actuating projections 52 are arranged at a distance from each other in the circumferential direction around the longitudinal axis A, whereby they are not, for example, arranged diametrically opposite each other offset by 180°, but deviating from this by an amount of 5° to 20° ( Fig. 3) This improves the grip with the thumb and forefinger of one hand.

[0072] A stop 54 may be provided on the base body 11, which defines the rest position R of the spindle unit 24 and / or the starting position I of the actuating ring 45. For this purpose, the actuating ring 45 and / or the spindle unit 24 and / or the rotary bearing 25 may abut the stop 54 when the spindle unit 24 is in the rest position R or the actuating ring 45 is in its starting position I. Fig. 5) An example is in the Fig. 5 and Fig. Figure 6 illustrates that the rotary bearing 25 rests against the stop 54, which is located inside the base sleeve 12 and is fixedly connected to the base sleeve 12. Alternatively, the stop 54 could also be located on a housing part or another part of the base body 11, against which the actuating ring 45 rests in its initial position I.

[0073] The micrometer 10 also has a measuring device 57 for acquiring a measured value and, for example, for acquiring the position of the measuring pin 19 in the longitudinal direction L. The measuring device 57 operates, for example, without contact. It has a sensor 58, which is arranged on the base body 11. A scale 59 is associated with the sensor 58 and is arranged on the measuring pin 19. The sensor 58 and the scale 59 work together to detect the position or change in position of the measuring pin 19 during a linear movement in the longitudinal direction L relative to the base body 11. The sensor 58 is communicatively connected to an evaluation unit 60 and transmits a sensor signal to the evaluation unit 60, which describes the position or change in position of the measuring pin 19 relative to the base body 11 in the longitudinal direction L.The evaluation unit 60 is communicatively connected to a display unit 61 in order to display the measured value on the display unit 61 based on the determined position of the measuring pin 19.

[0074] Based on the Fig. 5 and Fig. Section 6 explains the operating principle of the micrometer screw 10.

[0075] The actuating ring 45 can be switched between a starting position I ( Fig. 5) and an actuation position B ( Fig. 6) are moved. During this movement, the actuating ring 45 is rotated about the longitudinal axis A and, by means of the second coupling device 47 (here: the slope of the guide track 48), is moved in the longitudinal direction L relative to the base body 11 during the rotation. As shown in Fig. As illustrated in Figure 6, the actuating ring 45 travels a longitudinal path x between its starting position I and its actuating position B parallel to the longitudinal direction L ( Fig. 6).

[0076] During this movement in the longitudinal direction L, the spindle unit 24 is also displaced by the longitudinal path x in the longitudinal direction L relative to the base body 11 against the preload force F of the preloading device 40. The rotary bearing 25 moves together with the spindle unit 24 in the longitudinal direction L away from the stop 54. By coupling the spindle unit 24 to the measuring pin 19 by means of the first coupling device 22, the measuring pin 19 is also moved by the longitudinal path x away from the contact surface 15 of the anvil 14. The measuring pin 19 performs a retraction movement when the actuating ring 45 is moved from the initial position I to the actuating position B. During this movement, the spindle unit 24 moves from the rest position R to a position P displaced or offset by the longitudinal path x in the longitudinal direction L, which can also be referred to as the lifting or initial position.

[0077] The spindle unit 24 has the same rotational position about the longitudinal axis A in both the rest position R and the offset position P. The actuating ring 45 is supported on the operating sleeve 26 by a friction-reducing axial bearing 46 (in particular a rolling bearing, for example a ball bearing), thus improving the rotatability of the actuating ring 45 relative to the operating sleeve 26. The operating sleeve 26 maintains its relative rotational position with respect to the base body 11 during rotation of the actuating ring 45.

[0078] The actuating ring 45 is operated manually by an operator, in particular with one or two fingers of the hand holding the micrometer 10. By applying a torque, the actuating ring 45 can be rotated or moved from its initial position I towards the actuating position B. As soon as the applied torque is released, the preload force F of the preloading device 40 ensures that the spindle unit 24 is forced back towards its rest position R. A restoring torque is generated on the actuating ring 45 via the second coupling device 47, which forces it back towards its initial position I. For this purpose, the second coupling device 47 is designed to be non-locking in the exemplary embodiment.This means that the actuating ring 45, by applying a torque, is able to displace the spindle unit 24 in the longitudinal direction L against the preload force F, and conversely, the preload force F can cause a return movement of the spindle unit 24 to the rest position R and of the actuating ring 45 to the initial position I. Forces and moments can be transmitted bidirectionally via the second coupling device 47.

[0079] In the Fig. 1, Fig. 5 and Fig. Figure 6 schematically illustrates an optional configuration of the micrometer 10. The evaluation unit 60 can have an interface 62, which is configured for wireless or wired communication with an external device. In the case of the Fig. In the embodiment shown in Figure 1, interface 62 is shown as a wired interface in the form of a USB interface.

[0080] The invention relates to a micrometer 10, which is in particular designed as a micrometer with a yoke. The micrometer 10 has a base body 11 on which a measuring pin 19 is mounted so as to be linearly movable, in particular translationally movable. A spindle unit 24 is rotatably mounted relative to the base body 11 about a longitudinal axis A. The longitudinal axis A extends in the longitudinal direction. It has a spindle 23 extending along the longitudinal axis A and an operating sleeve 26, which is rotatably connected to the spindle 23 and can be manually rotated by an operator. The spindle 23 is coupled to the measuring pin 19 by means of a first coupling device 22, so that rotation of the spindle 23 causes a linear movement of the measuring pin 19. The first coupling device 22 can, for example, be a threaded connection.

[0081] A preloading device 40 generates a preload force F in the longitudinal direction L, which acts between the spindle unit 24 and the base body 11 and forces the spindle unit 24 into a rest position R. Against the preload force F, the spindle unit 24 can be displaced in the longitudinal direction L relative to the base body 11. An actuating ring 45 is supported on the spindle unit 24 and is coupled to the base body 11 by means of a second coupling device 47. The second coupling device 47 is designed such that a rotation of the actuating ring 45 about the longitudinal axis A simultaneously causes a linear movement of the actuating ring 45 in the longitudinal direction L relative to the base body 11. Due to this longitudinal movement of the actuating ring 45, the spindle unit 24 can be moved from the rest position R to a position P displaced by a longitudinal distance x, whereby the measuring pin 19 is moved together with the spindle unit 24 by the longitudinal distance x in the longitudinal direction L.The movement of the spindle unit 24 from its rest position R to position P results in a retraction movement of the measuring pin 19, while a movement of the spindle unit 24 from position P to its rest position R results in an extension movement of the measuring pin 19. Alternatively, the actuating ring 45 can be fixed in the longitudinal direction L, with the second coupling device 47 causing a movement in the longitudinal direction L of the measuring pin 19 together with the spindle unit 24 when the actuating ring 45 is rotated about the longitudinal axis A. The micrometer screw 10 provides improved ergonomics for operation. Reference symbol list: 10 micrometer 11 Basic bodies 12 Base sleeve 13 hangers 14 Anvil 15 Plant area 19 Measuring pin 20 plain bearings 21 Final section 22 first coupling device 23 Spindle 24 spindle unit 25 swivel bearings 26 Operating sleeve 27 Connection device 29 Connecting pin 31 external threads 32 internal threads 33 locking projection 34 Longitudinal recess 35 cavity 40 Pre-tensioning device 41 coil spring 42 Support ring 45 Actuating ring 46 axial bearings 47 second coupling device 48 Guide rail 49 guide bodies 50 guide groove 51 Guide stop 52 Actuation lead 53 Operating area 54 attacks 57 Measuring device 58 Sensor 59 Body of measurement 60 Evaluation unit 61 Display device 62 Interface A Longitudinal axis B Actuation position F Preload force I Starting position L Longitudinal direction P Position R Resting position x Longitudinal path

Claims

[1] Micrometer screw (10) having: - a basic body (11), - a measuring pin (19) mounted so as to be linearly movable in a longitudinal direction (L) along a longitudinal axis (A) relative to the base body (11), - comprising a spindle unit (24) rotatably mounted about the longitudinal axis (A), a spindle (23) extending along the longitudinal axis (A), and an operating sleeve (26) enclosing the longitudinal axis (A), wherein the spindle (23) is coupled to the measuring pin (19) by means of a first coupling device (22), - a preloading device (40) configured to generate a longitudinally directed (L) preload force (F) between the spindle unit (24) and the base body (11), - an actuating ring (45) rotatably mounted about the longitudinal axis (A), which is coupled to the spindle unit (24) in the longitudinal direction (L) and which is coupled to the base body (11) by means of a second coupling device (47) such that a rotation of the actuating ring (45) causes a displacement of the spindle unit (24) and the measuring pin (19) in the longitudinal direction (L) relative to the base body (11) against the preload force (F) of the preload device (40). [2] Micrometer screw according to claim 1, wherein the first coupling device (22) couples the spindle (23) and the measuring pin (19) such that a rotation of the spindle (23) causes a displacement of the measuring pin (19) along the longitudinal axis (A). [3] Micrometer screw according to claim 1 or 2, wherein the actuating ring (45) and the operating sleeve (26) are arranged adjacent to each other in the longitudinal direction (L). [4] Micrometer screw according to one of the preceding claims, wherein the rotation angle range of the actuating ring (45) about the longitudinal axis (A) is a maximum of 180° or a maximum of 90° or a maximum of 60°. [5] Micrometer screw according to one of the preceding claims, wherein the spindle unit (24) is rotatably mounted on the base body (11) by means of a rotary bearing (25). [6] Micrometer screw according to claim 5, wherein the spindle unit (24) and the rotary bearing (25) form a longitudinally movable assembly (L) which is arranged to be displaceable in the longitudinal direction (L) on the base body (11). [7] Micrometer screw according to one of the preceding claims, wherein the first coupling device (22) provides a first coupling ratio defined as the length of the linear movement of the measuring pin (19) in the longitudinal direction (L) divided by the number of revolutions of the spindle (23), wherein the second coupling device (47) provides a second coupling ratio defined as the length of the linear movement of the measuring pin (19) in the longitudinal direction (L) divided by the number of revolutions of the actuating ring (45) and wherein the first coupling ratio and the second coupling ratio have different values. [8] Micrometer screw according to claim 7, wherein the first coupling ratio is smaller than the second coupling ratio. [9] Micrometer screw according to one of the preceding claims, wherein the first coupling device (22) is designed to have a self-locking feature. [10] Micrometer screw according to one of the preceding claims, wherein the second coupling device (47) is designed such that it is self-locking. [11] Micrometer screw according to one of the preceding claims, wherein the preload force (F) generated by means of the preload device (40) forces the actuating ring (45) into a starting position (I). [12] Micrometer screw according to claim 11, wherein the initial position (I) is defined by a stop (54) on the base body (11) against which the actuating ring (45) or a component (24, 25) movable together with the actuating ring (45) in the longitudinal direction (L) rests in the initial position (I). [13] Micrometer screw according to one of the preceding claims, wherein the first coupling device (22) is a threaded connection between the spindle (23) and the measuring pin (19). [14] Micrometer screw according to one of the preceding claims, wherein the second coupling device (47) has at least one guide track (48) extending along a helix about the longitudinal axis (A) and at least one guide body (49) arranged to be movable relative to the guide track (48). [15] Micrometer screw according to claim 14, wherein the guide track (48) is a guide groove (50) and the guide body (49) engages in the guide groove (50). [16] Micrometer screw according to claim 14 or 15, wherein the guide track (48) on the actuating ring (45) and the guide body (49) is connected directly or indirectly to the measuring pin (19) and the spindle (23).

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