Control knob for manual fine-tuning of the setup, and tool for mounting such a control knob.

Abstract

Control knob for manual fine adjustment of equipment, with a base body (10) and a scale ring (11) rotatable relative to the base body (10), wherein the base body (10) and the scale ring (11) have mutually complementary guide elements, one of which is a groove (23), characterized in that the groove (23) has a contour complementary to the other guide element.

Description

[0001] The present invention relates to a control knob for manual fine adjustment of a device, comprising a base body and a scale ring rotatable relative to the base body, wherein the base body and the scale ring have mutually complementary guide elements, one of which guide element is a groove.

[0002] Such a control button is known from DE 20 2015 101 932 U1.

[0003] Control knobs are used for fine adjustment of devices, such as the relative distance between two tool components. Specific application examples include depth adjustment in milling, turning, for XY tables, CNC engraving machines, or for knurling tools. Furthermore, such a control knob can also be advantageously used for adjusting the stroke of (pneumatic) cylinders. Many other general industrial applications are conceivable.

[0004] To date, the control heads used have mostly been fixed scale ring knobs, scale rings with threaded pins or scale rings with O-rings or leaf / disk springs.

[0005] Fixed dial knobs may have a permanently engraved scale, but this cannot be reset. This means that the user must change the current position of the dial every time they want to make a relative adjustment (from a reference plane). Therefore, these control knobs are not suitable for relative adjustments, only for absolute adjustments.

[0006] With a scale ring with a threaded pin, a tool must be used every time the user wants to reset the scale ring. This makes this solution impractical. Furthermore, vibrations can affect the threaded pin and loosen it, resulting in the loss of the set position.

[0007] For scale rings with O-ring or leaf / disk springs, at least three main parts are required to secure the scale ring in position.

[0008] As far as the applicant is aware, there are currently no control knobs available that allow mechanical relative adjustment with a repeatable accuracy of 0.05 mm. According to the applicant's observations, this is due to the fact that the base body and the scale ring cannot be rotated relative to each other with the required ease, and the known control knobs are composed of a multitude of components and are therefore complex in design.

[0009] The invention is therefore based on the problem of developing a control knob of the type mentioned at the outset in such a way that devices can be manually adjusted with a high repeat accuracy of, for example, 0.05 mm.

[0010] To solve this problem, the control knob according to the invention is characterized in that the groove has a contour complementary to the other guide element.

[0011] The applicant has surprisingly discovered that the base body and the scale ring can be rotated more easily relative to each other by means of a groove with a shape complementary to the other (complementary) guide element. The control knob according to the invention thus requires only two main components, namely the base body and the scale ring. The guide elements fulfill three functions: Friction is reduced, making it easier for the user to reset the scale ring. At the same time, the friction is still high enough to prevent unintentional adjustment, e.g., due to vibrations. Furthermore, the scale ring and the base body are securely axially secured against accidental removal and thus unwanted disassembly.

[0012] According to a further development of the invention, the groove is shaped like a circular segment. The other, complementary guide element is a ball with approximately the same diameter. This allows for particularly smooth rotation of the base body relative to the scale ring. This is due to the ball's complete circumference contacting the circular segment-shaped groove, whereas a ball only contacts a V-shaped groove at two points. Furthermore, the ball sits perfectly in the groove, preventing accidental disassembly of the base body from the scale ring.

[0013] According to a particularly simple design, the ball can be preloaded toward the groove by a spring, particularly a helical spring. This simultaneously secures the base body and the scale ring to each other in the axial direction. No additional securing elements are required. The ball, which corresponds to the shape of the groove, reduces the preload on the spring and thus the pressure force of the ball on the groove, which further facilitates rotation of the base body relative to the scale ring.

[0014] For good guidance and axial locking, it is advantageous to provide at least two complementary guide elements distributed around the circumference. The guide elements should be distributed equidistantly around the circumference. Two diametrically opposed guide elements have been shown to be completely sufficient.

[0015] The control knob according to the invention can further comprise a threaded bolt guided in a complementary threaded bore in the base body or the scale ring. This serves to axially displace an element of the device to be adjusted. Furthermore, an anti-rotation device can be provided to prevent unintentional rotation and thus misalignment of the element. According to a structurally simple embodiment, the anti-rotation device can be designed as a lock nut. A knurled nut is suitable for ease of operation. A spring washer or spring ring placed underneath improves the effect of the lock nut.

[0016] As an alternative to the internal thread, the base body or the scale ring can also have a through hole in which a shaft is held.

[0017] The invention further relates to a tool for easily assembling the scale ring and base body. The tool has a forked shape and is designed and constructed to hold the other guide element in an assembly position during assembly of the scale ring to the base body, for example, to press the ball in against the force of the spring. The base body and scale ring can thus be easily connected to each other.

[0018] Further features of the invention emerge from the further dependent claims and the following description based on an exemplary embodiment illustrated in the drawing, from which further advantages of the invention also emerge. In the drawing: Fig. 1 a base body and a scale ring for a control knob with the features of the invention in a perspective exploded view, Fig. 2 the control knob according to the invention in vertical section, Fig. 3 a tool for mounting the control button according to Fig. 2 Fig. 4 a detail of the control knob according to Fig. 2 with a lock nut.

[0019] The control knob shown in the drawing comprises a base body 10 and a scale ring 11. In this case, the base body 10 is formed in one piece and has a gripping portion 12 of larger diameter, immediately adjacent to it a sliding portion 13 of medium diameter, and, immediately adjacent to it, a shoulder 14 with the smallest diameter compared to the gripping portion 12 and sliding portion 13. The gripping portion 12 is knurled on its casing 15 to facilitate gripping and turning by the user. RAA knurling with straight grooves is used for this purpose.

[0020] Two diametrically opposed and radially directed blind holes 16 are provided in the sliding area 13. Alternatively, only one, three, or more blind holes 16 can be provided. The blind holes 16 should be distributed equidistantly around the circumference.

[0021] A compression spring, in this case a helical spring 17, is inserted into each of the blind bores 16 and is supported on the base of the blind bore 16. At the opposite, outer end of the helical spring 17, a ball 18 is inserted into the blind bore 16, which protrudes at least partially.

[0022] The base body 10 is further provided with a through-bore 20 extending along its longitudinal axis 19. In the present case, the through-bore 20 is formed as a threaded bore over its entire length, but may also be formed as a threaded bore only over part of its length or not at all (simple bore).

[0023] In the case of a simple, unthreaded bore, a shaft is guided in the through-bore 20, which can be connected to the base body 10 in a rotationally fixed manner, e.g., by a press fit or other suitable means. In the present case, however, a complementary threaded bolt 21 is provided in the through-bore 20, which is firmly connected in a suitable manner to a device to be actuated. By rotating the base body 10 relative to the threaded bolt 21, the threaded bolt 21 is moved axially, and with it the device to be actuated.

[0024] The scale ring 11 is guided with its inner surface 22 in a sliding manner on the sliding area 13 of the base body 10 and can thus be rotated relative to the base body 10 about the common longitudinal axis 19. To axially secure the scale ring 11 to the base body 10, the scale ring 11 has a circumferential groove 23 on its inner surface 22 that complements the balls 18. The balls 18 engage in this groove 23, being preloaded outwardly against the groove 23 by the springs 17. The groove 23 can also have a polished surface, which reduces friction and at the same time further counteracts unintentional disassembly of the base body 10 from the scale ring 11.

[0025] The groove 23 and the balls 18, which complement the guide element, also have a complementary shape. The groove 23 therefore has the shape of a circular segment, which corresponds to the spherical shape. The circular segment for the groove 23 and the ball 18 have approximately the same, ideally the same, diameter.

[0026] On its outer surface, the scale ring 11 also has a grip area 24, which is knurled for easier operation. RAA knurling with straight grooves is also used for this purpose.

[0027] The knurling with straight, axially extending grooves on the base body 10 and / or scale ring 11 ensures good resistance when the base body 10 and the scale ring 11 are rotated against each other with the operator's fingers, while simultaneously ensuring low friction in the axial direction. Furthermore, for the same reason, the diameter of the scale ring 11 and / or the base body 10 should not expand in the direction away from each other, i.e., in this sense, they should be designed in the shape of a truncated cone. In the exemplary embodiment shown here, they are cylindrical. To further reduce friction when gripping with the fingers, the outer surface of the base body 10 and / or the scale ring 11, in particular the flanks of the knurling, should be polished.Tests conducted by the applicant on a prototype have shown that the fingers slip off in the axial direction at a tensile force of just 25 N, while a tensile force of 34 N was required to detach the base body 10 from the scale ring 11. This effectively prevents the base body 10 from being accidentally pulled off the scale ring 11.

[0028] Furthermore, the scale ring 11 has a scale area 25 provided with equidistant graduations. In the present case, ten graduations 26 are provided, numbered 0 to 9, each subdivided by subdivisions 27 located centrally between two graduations 26. Of course, a different number of graduations 26 can also be provided, which may not be further subdivided or may be further subdivided by a different subdivision 27.

[0029] By turning the scale ring 11 on the base body 10, the control knob can be “zeroed”.

[0030] Depending on the thread pitch of the internal thread in the through-hole 20 and the associated threaded bolt 21 or the thread attached to the shaft, one rotation of the base body 10 results in a specific distance as axial displacement of the threaded bolt 21 and thus of the device to be actuated. For example, with a thread pitch of 1 mm, the distance of axial displacement in one rotation is also 1 mm. In the present case of the scale ring 11 with a division from 0 to 9 on the scale ring 11, one unit on the scale ring 11 corresponds to 0.1 mm of axial displacement. With the intermediate markings ("half steps"), an accuracy of 0.05 mm is achieved.

[0031] Of course, any type of thread or pitch is possible. For example, instead of a threaded bolt 21 with a metric thread, a bolt with a trapezoidal thread or a recirculating ball screw can be used.

[0032] To prevent the position of the device being adjusted from being accidentally changed, an anti-twist device can be provided to prevent the base body 10 and threaded bolt 21 from accidentally twisting against each other. Fig. In the embodiment shown in more detail in Figure 4, a lock nut 28 is provided. Additionally, a spring washer, e.g., DIN 137 A or B, or a spring washer 35, e.g., according to DIN 127, can be provided between the lock nut 28 and the base body 10 to prevent accidental loosening.

[0033] Furthermore, according to the Fig. In the embodiment shown in Figure 4, a spacer 36 is also provided between the lock nut 28 and the base body 10. In the present case, the spacer 36 is formed as a spacer ring and is integral with the lock nut 28. It surrounds the spring washer 35. Alternatively, the spacer ring can also be formed integrally with the base body 10 or, although less preferably, as a separate component. Furthermore, the spacer 36 can then be provided as individual projections distributed preferably equidistantly around the circumference, e.g., two opposing projections or three projections.

[0034] The spacer 36 creates a defined gap 37 between the lock nut 28 and the base body 10. The spacer 36 should be dimensioned such that the thickness of the gap 37 corresponds to the normal working stroke of the spring washer or spring ring 35, thus preventing plastic deformation of the spring washer or spring ring 35 due to overtightening the lock nut 28. This also ensures that the lock nut 28 is only tightened far enough to be easily loosened by hand without tools when the control knob needs to be readjusted.

[0035] Furthermore, the spacer 36 provides additional friction between the lock nut 28 and the base body 10. The spring washer or spring washer 35 also provides a constant force against vibrations. The combination of the spacer 36 with extra friction and the spring washer or spring washer 35 thus provides reliable locking even under strong vibrations.

[0036] The lock nut 28 is designed as a knurled nut. For easier operation, the outer surface of the lock nut 28 also has a knurling 29, in particular an RAA knurling with straight grooves.

[0037] The above description assumes that the bolt 21 has a thread of some kind and that the bore 20 has a complementary internal thread. Alternatively, the bore 20 can also be a simple through-hole, and the thread can be assigned to the device to be adjusted. In this case, it is sufficient if the bolt 21 is designed as a threaded bolt at its end facing the device. Here, too, the only important thing is that the threaded section covers at least the desired adjustment range.

[0038] This is particularly suitable for a recirculating ball screw thread for bolt 21 due to the larger space available.

[0039] In this variant, the bolt 21 can be connected to the base body 10 in any suitable way. A one-piece connection is also possible, although not preferred for manufacturing reasons. A press connection is more suitable here. This can be a press fit between the bore 20 and the bolt 21. Furthermore, the bore 20 can be conical. A sleeve with a complementary cone is then inserted between the bore 20 and the bolt 21 and the pressing is created by axially displacing the sleeve relative to the base body 10. This can be done by a screw connection. Furthermore, for better protection against rotation, the bore 20 and the section of the bolt 21 engaging in it can be non-circular, e.g. as a polygon or with a flattened area on one long side.

[0040] In order to facilitate the assembly of the base body 10 and the scale ring 11, a special tool 30 is provided, which is Fig. 3 is shown in more detail. The tool 30 is fork-shaped and has a handle 31 and a fork 32 formed thereon. The mouth 33 of the fork 32 has a width corresponding to the diameter of the sliding area 13 of the base body 10. Furthermore, the fork 32 is provided at its free ends with chamfers 34 that converge slightly outwards from the handle 31 in order to facilitate sliding onto the sliding area 13 and pressing the balls 18 into the bores 16. The thickness of the fork 32, i.e. the thickness perpendicular to the image plane in Fig. 3, is smaller than the diameter of the ball 18, so that it partially protrudes downwards, towards the shoulder 14.

[0041] For assembly, the fork 32 is pushed over the sliding area 13 so that the balls 18 are almost completely pressed into the holes 16. The lower sliding area 13 can now be pushed into the scale ring 11, and then the fork 32 can be retracted. After complete assembly, the balls 18 snap into the groove 23. List of reference symbols: 10 basic bodies 11 Scale ring 12 Grip area 13 Sliding area 14 Approach 15 coat 16 blind bore 17 spring 18 ball 19 Longitudinal axis 20 through holes 21 bolts 22 inner surface 23 grooves 24 grip area 25 scale range 26th division 27 lower division line 28 Lock nut 29 Knurling 30 tools 31 handle 32 fork 33 mouth 34 chamfers 35 spring washer or spring washer 36 spacer 37 gap QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 20 2015 101 932 U1

[0002]

Claims

[1] Control knob for manual fine adjustment of a device, comprising a base body (10) and a scale ring (11) rotatable relative to the base body (10), wherein the base body (10) and the scale ring (11) have mutually complementary guide elements, one of which guide elements is a groove (23), characterized by that the groove (23) has a contour complementary to the other guide element. [2] Control button according to claim 1, characterized by that the groove (23) has the shape of a circular segment and the other guide element is a ball (18) of approximately the same diameter. [3] Control button according to claim 2, characterized by that the ball (18) is prestressed by a spring (17) in the direction of the groove (23). [4] Control button according to claim 3, characterized by that the spring (17) is a helical spring. [5] Control button according to one of claims 1 to 4, characterized bythat two or more complementary guide elements are arranged distributed in the circumferential direction. [6] Control button according to claim 5, characterized by that the complementary guide elements are arranged equidistantly around the circumference. [7] Control knob according to one of claims 1 to 6, further comprising a bolt (21) which is guided in a complementary bore (20) in the base body (10) or the scale ring (11). [8] Control button according to claim 7, characterized by that the bolt (21) is designed as a threaded bolt, a trapezoidal threaded bolt or a ball screw, at least at its end facing the base body (10), and the bore (20) is designed to be complementary thereto. [9] Control button according to claim 7, characterized bythat the bore (20) is designed as a through-bore and the bolt (21) is designed, at least with its end facing the device, as a threaded bolt, a trapezoidal threaded bolt or a ball screw which cooperates with a complementary bore on the device. [10] Control button according to one of claims 7 to 9, characterized by that the bolt (21) can be secured against unintentional rotation by means of an anti-rotation device, in particular a lock nut (28). [11] Control button according to claim 10, characterized by that the lock nut (28) is a knurled nut. [12] Control button according to claim 10 or 11, characterized by that a spring washer or a spring ring (35) is provided between the lock nut (28) and the base body (10) or the scale ring (11). [13] Control button according to one of claims 10 to 12, characterized bythat a spacer (36) is arranged between the lock nut (28) and the base body (10). [14] Control button according to claim 13, characterized by that the spacer (36) is designed as a spacer ring, in particular formed integrally with the lock nut (28). [15] Control button according to one of claims 1 to 14, characterized by that the base body (10) and / or the scale ring (11) has a grip area (12; 24) with a knurled casing (15) with straight knurling. [16] Control button according to claim 15, characterized by that the grip area (12; 24) on the base body (10) and / or on the scale ring (11) is cylindrical. [17] Control button according to one of claims 1 to 16, characterized by that the sliding area (13) on the base body (10) and / or the scale area (25) on the scale ring (11) is polished. [18] Tool for assembling the control knob according to one of claims 1 to 17, characterized bya fork-shaped form and arranged and designed to hold the other guide element in an assembly position during assembly of the scale ring (11) with the base body (10).

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