Coupling element for receiving a probe tip in a probe measuring apparatus, screw insert for receiving a probe tip in a probe measuring apparatus, coupling assembly for a probe insert in a probe measuring apparatus, and probe measuring apparatus

A coupling element for receiving a probe tip in a probe measuring apparatus has a journal at one end with a first connecting/coupling region. A screw insert has a first connecting/coupling region at one end with a recess, in particular for connecting to the coupling element 16. The journal of the coupling element forms, on an outer surface, or the recess of the screw insert forms, on an inner surface, multiple thread segments or respectively which do not adjoin one another in a radial circumferential direction. A probe measuring apparatus includes the coupling element, the screw insert, a coupling arm/measuring shaft, and a probe insert connected to the coupling arm by way of the coupling element and the screw insert.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority, under 35 U.S.C. § 119, of German patent application DE 10 2020 113 401.0, filed May 18, 2020; the prior application is herewith incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to a coupling element for receiving a probe tip in a probe measuring apparatus, a screw insert for receiving a probe tip in a probe measuring apparatus, a coupling assembly for a probe insert in a probe measuring apparatus, and one or more probe measuring apparatus-es.

A probe measuring apparatus, for example a multi-coordinate probe measuring apparatus, also referred to merely as 3D probe for short, which allows distance measurements to be performed both in the direction of a measuring axis and transversely with respect thereto, is known for example from our commonly assigned U.S. Pat. No. 7,024,786 B2 (cf. WO 02/103282 A1).

This probe measuring apparatus comprises a housing on which a probe lever, sometimes also referred to as probe arm, is guided so as to be displaceable in the direction of a measuring axis defined by the housing. The probe lever is, by means of a universal joint, for example in this case in the form of a ball joint in U.S. Pat. No. 7,024,786 B2, furthermore guided on the housing so as to be pivotable in all directions about a pivot point situated on the measuring axis, and said probe lever is resiliently preloaded by a resetting spring.

The probe lever has a probe insert which projects out of the housing and which is also often descriptively referred to for short as probe tip, the free probe end of which, formed by a probe ball, defines a probe reference point which lies on the measuring axis when the probe lever is in the rest position.

In relation to the pivot point, a coupling arm of the probe lever, also referred to as measuring shaft of the probe lever, projects, oppositely to the probe insert, into a circular cylindrical guide opening, which is central in relation to the measuring axis, of the housing.

The probe insert, which has not only the probe ball but also a pin, which receives the probe ball, and a sleeve, which is in turn connected to the pin, is screw-connected to the coupling arm by means of a screw connection arrangement which has a centering element and a threaded rod with external thread.

For this purpose, the probe insert, in this case the sleeve of the probe insert, is held, at the other end of the joint ball, in a corresponding bore at that end of the centering element which lies in the direction of the probe insert. At the other end of said bore end, the centering element has an internal thread which is screwed together with the threaded rod or with the external thread of the threaded rod. At that end of the threaded rod which is averted from the probe insert, said threaded rod is screw-connected—by means of an external thread on the threaded rod—in an internal thread of the coupling arm.

A dial gauge held on the housing records the position of the measuring shaft or of the probe lever relative to the housing.

Improper usage of such a probe measuring apparatus during use can result in damage to the probe insert, for example can break in the region of the (ceramic) sleeve, which is composed of ceramic and which serves as a predetermined breaking point, of the probe insert. A replacement or exchange of the probe insert is then necessary.

BRIEF SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a coupling which overcomes a variety of disadvantages of the heretofore-known devices and methods of this general type and which provides for a simple, inexpensive and quickly exchangeable coupling of a probe insert in a probe measuring apparatus.

With the above and other objects in view there is provided, in accordance with the invention, a coupling element for receiving a probe tip in a probe measuring apparatus, the coupling element comprising:

a journal having a first connecting and coupling region formed at an end thereof; and

said journal having an outer surface formed with a plurality of thread segments which do not adjoin one another in a radial circumferential direction.

With the above and other objects in view there is also provided, in accordance with the invention, a screw insert for receiving a probe tip in a probe measuring apparatus, the screw insert comprising:

a first connecting and coupling region formed at one end and configured for connecting to a coupling element as outlined above;

said first connecting and coupling region having a recess with an inner surface and multiple thread segments formed on said inner surface that do not adjoin one another in a radial circumferential direction.

In other words, the objects of the invention are achieved by way of a coupling element for receiving a probe tip in a probe measuring apparatus, a screw insert for receiving a probe tip in a probe measuring apparatus. There is also provided a coupling assembly for a probe insert in a probe measuring apparatus, and one or more probe measuring apparatuses, having the features of the respective claims. Dependent claims and the following description relate to advantageous refinements of the invention.

Expressions used herein, such as axial and radial, are to be understood—unless explicitly defined otherwise—as being in relation to a measuring axis of a probe measuring apparatus which has the items according to the invention.

The coupling element according to the invention has, at one end, a journal which forms a first connecting/coupling region. The journal forms, on an outer surface, multiple thread segments which do not adjoin one another in a radial circumferential direction.

The screw insert according to the invention (also) has, at one end, a first connecting/coupling region, in particular for connecting to the coupling element,—having a recess, on the inner surface of which there are (likewise) formed multiple thread segments which do not adjoin one another in a radial circumferential direction.

(Such) a thread segment (— be it on the coupling element or on the screw insert —) may in this case be formed by one or more depressions which form in each case one part of a thread turn (partial thread turn) (, wherein, then, “elevations” which delimit such a depression or such a partial thread turn can be regarded—and referred to—as thread flanks).

In simple terms, — in a radial circumferential direction—between the thread segments, there are formed (on the out-er journal surface (in the case of the coupling element) or on the inner recess surface (in the case of the screw insert) thread-free regions or thread-free sections, hereinafter referred to for short and for simplicity as discontinuities, for example substantially smooth partial cylinder surfaces/shells.

That is to say, in descriptive terms, on the journal sur-face or inner surface of the recess respectively, the thread segments (in the case of the journal of the coupling element, in descriptive terms, external thread segments or, in the inner recess of the screw insert, in descriptive terms, internal thread segments) and the thread-free regions or discontinuities alternate in a radial circumferential direction.

This has proven to be advantageous in that it is possible in this way for a corresponding counterpart with respect to the coupling element or with respect to the screw insert, for example the screw insert with respect to the coupling element or vice versa, to be easily and quickly coupled thereto, for example by (quick) rotary coupling, that is to say by axial pushing on/in and then (relative) rotation.

Here, it is the case—during the axial pushing on/in—that the thread segments of one element, for example of the coupling element or the external thread segments of the coupling element, “plunge” into the discontinuities of the other element (counterpart element), for example of the screw insert (or vice versa, that is to say the internal thread segments of the counterpart element, for example of the screw insert, plunge into the discontinuities of the element, for example of the coupling element)—until said elements are then rotated relative to one another—wherein, then, the external thread segments and internal thread segments engage into one another.

In short, the coupling element and screw insert can—by way of this rotary coupling—be easily and quickly coupled—and braced together in a precise manner. The connection—and thus the advantages of the coupling element and/or screw insert—proves to be more stable, better, in particular quicker and free from play and with centering action.

It is furthermore expedient here if the discontinuities—between the thread segments—are radially set back in relation to the thread segments. In descriptive terms, the discontinuities—between the thread segments—lie— in the case of the coupling element—radially further to the inside than the thread segments or lie—in the case of the screw insert—radially further to the outside than the thread segments. The axial insertion (of element and counterpart element) or “plunging-in” (of the thread segments into the discontinuities) can take place more easily.

This rotary coupling can also be further simplified if the thread segments of one element, for example of the coupling element, and the discontinuities of the counterpart element, for example of the screw insert, are adapted to one another in particular in terms of their extent in a circumferential direction. That is to say, if the extent in a circumferential direction of the thread segments (of one element) is equal to or in particular less than the circumferential direction extent of the discontinuities (of the counterpart element), then the element and counterpart element can more easily be axially displaced relative to one another or plunge into one another.

In particular, it is also expedient (— be it in the case of the coupling element or in the case of the screw insert —) if the pitch profiles in the case of all depressions that form the partial thread turns are identical.

In this way, jamming-free coupling of the coupling element or of the screw insert with a corresponding counterpart, for example of the coupling element and the screw insert, can be made possible.

Expressed/explained in simplified or descriptive terms, identical pitch profiles have the result that the same “stroke” is set at/in the case of every partial thread turn. Different strokes can otherwise lead to instances of jamming or can impede a coupling of the coupling element or of the screw insert to a corresponding counterpart.

Here, it is however possible for the—identical—pitch profiles to themselves in turn each be constant—or to vary, in particular to be degressive.

In particular, the degressive configuration of a partial thread turn allows an (initially) quick engagement during a process of coupling of the coupling element or of the screw insert to a corresponding counterpart, for example during the process of rotary coupling (see above).

Furthermore, it may also be provided that (— be it in the case of the coupling element or in the case of the screw insert —) the depressions that form the partial thread turns are formed such that they do not form a common thread turn.

That is to say, expressed in descriptive or simplified terms, all depressions or partial thread turns do not lie on an (imaginary continuous) common helical line.

Furthermore, it may (— be it in the case of the coupling element or in the case of the screw insert —) also be expedient for gaps to be formed between the partial thread turns of a thread segment.

Expressed in descriptive or simplified terms, partial thread turns of a thread segment do not directly adjoin one another in an axial direction, it rather being the case that, between in each case two partial thread turns, there are in each case depressions that are wider than the partial thread turns themselves.

In this way—in the case of coupling of the coupling element or of the screw insert to a corresponding counterpart—the external thread in the case of the coupling element or the internal thread in the case of the screw insert can be more easily brought together with the corresponding in-ternal thread or the corresponding external thread of the counterpart.

In particular, it is expedient from a production aspect if (— be it in the case of the coupling element or in the case of the screw insert —) at least two or more, in particular all, thread segments are of identical form.

Preferably, it may also be provided that three thread segments, which are in particular distributed uniformly in a radial circumferential direction, are arranged on the out-er surface of the journal or on the inner surface of the recess respectively. It is also possible for four or even more thread segments, which are in particular distributed uniformly in a radial circumferential direction, to be provided.

These thread segments may preferably also be arranged at uniform angular intervals.

This may then also apply correspondingly to the discontinuities on the journal or on the inner surface of the recess respectively.

Furthermore, it may also be provided that a recess which has an internal thread is provided in the journal, which forms the first connecting/coupling region, of the coupling element.

This recess may for example be provided for coupling the coupling element—instead of via the thread segments on the journal surface—to another, alternative counterpart, for example a threaded rod, as is provided for example by the 3D probe from U.S. Pat. No. 7,024,786 B2. The “original” coupling facility of the coupling element by way of the thread segments on the journal surface therefore does not need to be dispensed with, and it is—expressed in simplified terms—supplemented by a further coupling facility. The coupling element can thus be used in a versatile manner. That is to say, in descriptive terms, interfaces open or multi-compatible with 3D probes.

Furthermore, a further journal which forms a second connecting/coupling region may be provided on the coupling element—at the other end thereof. This further journal, too, may be formed with a further recess. This further recess may for example serve for receiving a probe tip/a probe insert. For example, said probe insert/probe tip may be screwed and/or adhesively bonded therein.

Provision may thus for example be made for a sleeve of a probe insert to be adhesively bonded in said further recess.

It is also expedient for a radially extending abutment surface for axial planar abutment to be provided on or in the case of the coupling element (also referred to for short merely as planar abutment). This may be oriented in particular in the direction of the journal end of the journal that forms the first connecting/coupling region—and may in particular also be provided for lying on a corresponding surface on a coupling arm/a measuring shaft.

It is also possible for the coupling element to have a substantially cylindrical subsection, on the outer surface of which there is formed a radially outwardly bulged bead, which runs in at least partially, in particular fully, encircling fashion in a radial circumferential direction, for radial centering (also referred to for short merely as centering, for example for centering of the coupling element in a recess in the coupling arm/measuring shaft, in which recess the coupling element is received).

This bead may, in particular after the journal which forms the first connecting/coupling region, be formed on the outer surface of the journal, in particular between planar abutment and the journal that forms the first connecting/coupling region.

Furthermore, it may also be provided that the coupling element provides a subsection, the outer circumference of which is non-circular in cross section. This non-circular configuration may be formed in particular by regions situated radially further to the inside and regions situated radially further to the outside.

Here, geometrical shapes and cross sections that deviate from a circle may be regarded as “non-circular”.

Accordingly, it is also expedient if an inner surface of a recess in the coupling arm/measuring shaft, in which recess the coupling element can be or is received, is of complementary form with respect to the non-circular con-figuration, in particular also has regions situated radially further to the inside and radially further to the outside.

It is thus then possible, if the coupling element is to be received in the coupling arm/measuring shaft, for said coupling element to be pushed into the recess thereof and then rotated—relative to the coupling arm/measuring shaft. Here, if the regions, situated radially further to the outside, of the coupling element or in/of the subsection of the coupling element abut against the regions, situated radially further to the inside, of the coupling arm/measuring shaft or in the recess of the coupling arm/measuring shaft or on the inner surface of the recess of the coupling arm/measuring shaft, then the coupling element and the coupling arm/measuring shaft (that is to say the play is obtained from the pairing) are braced relative to one another—and can thus also be centered relative to one another.

It may also be advantageous if the screw insert, at the other end, has a journal which forms a second connecting/coupling region and on the outer surface of which there is formed an external thread, or if the screw insert, at the other end, has a bore which forms the second connecting/coupling region120and which has an inserted (hexagonal socket) screw.

By means of this external thread or this screw or the (external) thread thereof, it is for example possible for the screw insert to be screwed together with an internal thread provided on the coupling arm.

Also, in the case of the screw insert, a reduced-diameter, substantially cylindrical intermediate region may be pro-vided between the first and the second connecting/coupling region. By means of this, the screw insert can have a certain degree of flexibility—in order to be able to compensate possibly occurring tolerances.

Axial planar abutment and/or centering may also be provided in the case of the screw insert. That is to say, in other words, it may be provided that the screw insert has a radially extending abutment surface for axial planar abutment or a substantially cylindrical subsection for radial centering (for example for centering of the screw insert in a recess in the coupling arm/measuring shaft, in which recess the screw insert is received)—both in particular for abutment and/or centering relative to the measuring shaft/the coupling arm.

In a refinement, it is also possible for a radially resilient structure to be provided on an outer surface of the screw insert, in particular in the region of the first connecting/coupling region.

It may furthermore be expedient here, because it is simple in terms of manufacturing, if the axially resilient structure is formed by means of spring clamp elements (“clip”).

Accordingly, it may then also be expedient if, on an inner surface of a recess in the coupling arm/measuring shaft, in which recess the screw insert can be or is received, there is formed a (detent engagement) structure in which said radially resilient structure on/of the screw insert can be engaged with detent action.

It may furthermore be expedient here, because it is simple in terms of manufacturing, if the (detent engagement) structure is formed by a radially encircling groove on the inner surface of the recess in the coupling arm/measuring shaft.

By means of these simple structural elements—of axially resilient structure of the screw insert and/or (detent engagement) structure of the coupling arm/measuring shaft—it is thus possible for the screw insert to be received and held securely in the coupling arm/measuring shaft in a simple manner.

It is possibly also expedient here for the screw insert to be formed with a means for securing against rotation relative to the coupling arm/measuring shaft.

The coupling assembly according to the invention provides the coupling element and the screw insert. Both may in particular be formed with the described configurations.

It is particularly expedient here if the thread segments of the coupling element and the thread segments of the screw insert are formed as corresponding internal/external threads that can be screwed together (see above with regard to the rotary coupling).

The respective discontinuities in the case of the coupling element and screw insert may also be adapted to one another (see above with regard to the rotary coupling).

The connection of coupling element and screw insert is then performed in particular by—quick—rotary coupling (see above), that is to say by axial insertion of the coupling element into the screw insert and then—mutual—(relative) rotation.

It is thus also particularly expedient for the coupling element and/or the screw insert or the coupling assembly to be used for receiving a probe tip in a probe measuring apparatus, in particular a 3D probe, it is thus possible for the probe tip to be easily and quickly installed (in the probe measuring apparatus) or exchanged (in the case thereof).

A probe measuring apparatus according to the invention provides (at least) the screw insert, in particular according to described configurations, and a coupling arm/measuring shaft, wherein the screw insert and the coupling arm/measuring shaft are connected to one another, in particular are screwed together or are formed as a single piece.

In particular, this connection of screw insert and coupling arm/measuring shaft may be realized by virtue of screw insert having, at the other end, the journal which forms the second connecting/coupling region and on the outer surface of which the external thread is formed, and the coupling arm providing the provided internal thread. The external thread of the screw insert and the internal thread of the coupling arm can then be screwed together.

A further probe measuring apparatus according to the invention may also have the coupling element, in particular according to described configurations, a screw insert, in particular according to described configurations, a probe insert, in particular a probe insert which has a probe ball, a pin and a sleeve, and a coupling arm/measuring shaft, wherein the probe insert is connected to the coupling arm/measuring shaft by means of the coupling element and by means of the screw insert connected to the coupling element.

Furthermore, in the case of the probe measuring apparatus, it may also be provided that the thread segments of the coupling element and the thread segments of the screw insert are formed as corresponding internal/external threads that can be screwed together.

The respective discontinuities may also be adapted to one another, such that the coupling element and the screw insert can be connected to one another by rotary coupling (see above).

As an alternative to the coupling element according to the invention which has the thread segments, it is also possible for a (further) coupling element to be provided which, at one end, has a journal which forms a first connecting/coupling region and on the outer surface of which there is formed (instead of the (multiple) thread segments (spaced apart by the discontinuities) a (continuous or uninterrupted) multi-turn external thread.

This alternative coupling element may also be refined with described refinements of the above-described coupling element which has the thread segments, such as in particular the recess with internal thread or the further recess with the further internal thread, the planar abutment or the centering means.

An advantage in the case of this alternative coupling element which has the multi-turn thread is in particular that, with such a coupling element, if it is screw-connected by means of said multi-turn thread, for example in a probe measuring apparatus, a greater axial feed/stroke can be realized for the same rotational angle (in relation to single-turn threads), whereby said coupling element can be screw-connected—more quickly than a part which has a conventional single-turn thread.

If the connection of a probe insert is then realized by means of such an alternative coupling element, which has the multi-turn thread, in the case of/in a probe measuring apparatus, a probe insert can thus be changed or exchanged in a short(er) time.

The above description of advantageous configurations of the invention contains numerous features that are in some cases depicted together in combination in the individual subclaims. These features may however expediently also be considered individually and combined to form further meaningful combinations.

Even if some terms have been used in each case in the singular or in conjunction with a numeral in the description or in the patent claims, the scope of the invention is not intended to be restricted to the singular or to the respective numeral for said terms. Furthermore, the words “a” or “an” are to be understood not as numerals but as indefinite articles.

The above-described characteristics, features and advantages of the invention, and the manner in which these are achieved, will become clearer and more distinctly understandable in conjunction with the following description of the exemplary embodiments of the invention, which will be discussed in more detail in conjunction with the drawing figures.

The exemplary embodiments serve for the explanation of the invention and do not restrict the invention to the combinations of features, including functional features, specified therein. Furthermore, for this purpose, suitable features of each exemplary embodiment may also explicitly be considered in isolation, taken from one exemplary embodiment, introduced into another exemplary embodiment in order to supplement the latter, and/or combined with any of the claims.

Identical parts/components and respective functions are denoted by the same reference designations throughout the drawing.

DETAILED DESCRIPTION OF THE INVENTION

The first portion of the following description relates toFIGS.1-4and pertains to a 3D probe insert/tip8with rotary coupling for a 3D probe2.

Expressions used here, such as axial and radial, are to be understood—unless explicitly defined otherwise—as being in relation to the measuring axis82of the 3D probe2.

The 3D probe2comprises a housing4(not illustrated in the figures) on which a probe lever6(cf.FIG.1,FIG.4) is guided displaceably in the direction of a measuring axis82defined by the housing4.

The probe lever6is, by means of a universal joint86, in this case in the form of a ball joint86, furthermore guided on the housing4so as to be pivotable in all directions about a pivot point situated on the measuring ax-is82, and said probe lever is resiliently preloaded by a resetting spring (not illustrated in the figures).

The probe lever6has, as shown inFIGS.1and4, a probe insert/probe tip8which projects out of the housing and the free probe end of which, formed by a probe ball10, defines a probe reference point which lies on the measuring axis82when the probe lever6is in the rest position.

As illustrated inFIGS.1and4, the probe lever6furthermore comprises a coupling arm80which—in relation to the pivot point—projects, oppositely to the probe insert8or oppositely to the direction84to the probe tip8, into a circular cylindrical guide opening, which is central in relation to the measuring axis82, of the housing4(not illustrated in the figures).

By means of a coupling assembly216, which has a coupling element16(cf.FIG.2) and a screw insert116(cf.FIG.3) connected to the coupling element16, as illustrated inFIGS.1and4, the probe insert8, which aside from the probe ball10has a (steel) pin12, which receives the probe ball10by means of a welded connection, and a (ceramic) sleeve14, which is in turn connected to the pin12, is screwed to the coupling arm80.

For this purpose, as described in more detail in conjunction withFIG.2, the (installed) coupling element16(then) provides, at its end pointing in the direction84of the probe tip8, a recess (26b) in the form of an axial bore which is open at one side (at the end side) and which serves for receiving the sleeve14of the probe insert8.

As shown inFIG.2(in views2-1,2-2,2-3, detail view of the coupling element16), the coupling element16has, at one end, a journal (24a) which forms a first connecting/coupling region18.

This journal (24a) forms, on an outer surface60, multiple, in this case three, thread segments28which do not adjoin one another in a radial circumferential direction62and which are arranged so as to be distributed uniformly in a radial circumferential direction62and which are identical in themselves and which are in the form of external thread components30, the partial thread turns30of which all have the same, slightly degressive pitch profile68or, for short, the same slightly degressive pitch68.

That is to say that, as shown inFIG.2, in a radial circumferential direction62, between the three thread segments28(on the outer journal surface60in the case of the coupling element16), there are formed three thread-free regions or thread-free sections, which are thus likewise arranged so as to be distributed uniformly in a radial circumferential direction62(so as to alternate with the thread segments28), and which are hereinafter referred to for short and for simplicity as discontinuities32and which are in this case in the form of smooth partial cylinder surfaces/shells.

Here, as can also be seen fromFIG.2, the three discontinuities32are, in a radial circumferential direction62, in each case somewhat longer than the three thread segments28—and, as is also illustrated inFIG.2, are formed so as to be situated radially further to the in-side, or radially set back, in relation to the thread segments28.

Furthermore, as shown inFIG.2, the journal (24a), which bears the external thread components30, of the coupling element16has an axial recess (26a), in the form of an axial bore which is open at one side (at the end side) and in which an internal thread34is provided.

Furthermore, as illustrated inFIG.2, a further journal24b, which forms a second connecting/coupling region20, is provided on the coupling element16—there at the other end of the journal (24a) that bears the thread segments28or the external thread components30.

Said further journal24balso provides a recess (26b) in the form of an axial bore which is open at one side (at the end side) and which serves (as shown inFIGS.1and4) for receiving the sleeve14of the probe insert8. That is to say, the sleeve14of the probe insert8is adhesively bonded in this recess (26b).

Furthermore, as shown inFIG.2, on the coupling element16, a radially extending abutment surface36which is directed in the direction of the journal (24a) that bears the thread segments28or the external thread components30is provided—on a radially outwardly extending flange-like projection42—for axial planar abutment against a counterpart surface44on the coupling arm80(also referred to for short merely as planar abutment).

As is also shown inFIG.2, the flange-like projection42provides, on its outer circumferential surface, a fluting46in order that it can be more easily gripped. A corresponding fluting48is also formed on the outer circumference of the further journal24b(there also in order that it can be more easily gripped).

Furthermore, the coupling element16provides—axially between the journal (24a), which bears the thread segments28and the external thread components30, and the flange-like projection42that provides the planar abutment—a substantially cylindrical subsection38, on the outer sur-face of which there is formed a radially outwardly bulged bead40which runs in encircling fashion in a radial circumferential direction and which serves for radial centering of the coupling element16in the coupling arm80(cf.FIGS.1and4) (also referred to for short merely as centering).

FIG.3shows the screw insert116in detail. As shown inFIG.3, the screw insert116likewise provides, at one end, a first connecting/coupling region118.

This first connecting/coupling region118has an axial recess124, in the form of an axial bore which is open at one side (at the end side) and on the inner surface70of which there are formed multiple, in this case three, thread segments126which do not adjoin one another in a radial circumferential direction62and which are arranged so as to be distributed uniformly in a radial circumferential direction62and which are identical in themselves and which are in the form of internal thread components128, the partial thread turns128of which all have the same, slightly degressive pitch profile68or, for short, the same slightly degressive pitch68.

That is to say that, as shown inFIG.3, in a radial circumferential direction62, between the three thread segments126(on the inner recess surface70in the case of the screw insert116), there are formed three thread-free regions or thread-free sections, which are thus like-wise arranged so as to be distributed uniformly in a radial circumferential direction62(so as to alternate with the thread segments126), and which are hereinafter again referred to for short and for simplicity as discontinuities130and which are in this case in the form of smooth partial cylinder surfaces/shells.

Here, as can also be seen fromFIG.3, the three discontinuities130are, in a radial circumferential direction62, in each case somewhat longer than the three thread segments126—and, as is also illustrated inFIG.3, are situated radially further to the outside, or radially set back, in relation to the thread segments126.

In short, the first connecting/coupling region118of the screw insert116is formed as a complementary, couplable counterpart/counter-element in relation to the first connecting/coupling region18of the coupling element16—or—the recess124, which bears the thread segments126—of the screw insert116is formed as a complementary, couplable counterpart/counter-element in relation to the journal (24a), which bears the thread segments28, of the coupling element16.

By means of these complementary elements, it is possible, as will be described, for the coupling element16and the screw insert116to be connected to one another easily and quickly—by rotary coupling.

Furthermore, as illustrated inFIG.3, a journal122, which forms a second connecting/coupling region120, is provided on the screw insert116—there at the other end of the recess124that bears the thread segments126or the internal thread components128.

On the outer surface140of the journal122, there is pro-vided an external thread134by means of which the screw insert116can be screwed into the coupling arm80(into an internal thread88thereof) (cf.FIGS.1and4).

Furthermore, as shown inFIG.3(and illustrated inFIG.4),—similarly to the coupling element16—on the screw insert116, there is provided—on a radially outwardly extending flange-like projection142—a radially extending abutment surface136which is directed in the direction of the journal122that bears the external thread134, which abutment surface serves for axial abutment against a counterpart surface144on the coupling arm80.

Furthermore, the screw insert116provides—axially be-tween the journal122that bears the external thread134and the flange-like projection142that provides the abutment—a substantially cylindrical subsection138for ra-dial centering in the coupling arm80.

As is also shown inFIG.3, the screw insert116furthermore also has a reduced-diameter, substantially cylindrical intermediate region132—axially between the first and the second connecting/coupling region118,120or axially between the flange-like projection142and the first connecting/coupling region118of the screw insert116—, whereby the screw insert116can have a certain flexibility in order to be able to compensate possibly occurring tolerances.

The installation of the probe insert8may be performed in the screw insert116that is screwed into the coupling arm80.

For this purpose, the screw insert116can be screwed by way of the external thread134, provided on the outer journal surface140, into the coupling arm80(into an in-ternal thread88thereof) (cf.FIGS.1and4).

For the fixing of the probe insert8, which is connected by way of its sleeve14to the coupling element16, to/on the coupling arm80(cf.FIGS.1and4), the journal (24a), which has the thread segments28with the external thread components30, of the coupling element16is then axially introduced/pushed into the recess124, which has the thread segments126with the internal thread components128, of the screw insert116(specifically until the axial planar abutment surface36abuts against the counterpart surface44of the coupling arm80), wherein the thread segments28of the coupling element16plunge into the discontinuities130of the screw insert116(or vice versa (32/126),—and are then braced by “relative rotation” (here, it is then the case that the external and in-ternal thread components30,128of the thread segments28,126engage into one another)—and thus coupled or held/fixed (rotary coupling).

This push-turn sequence—that is to be performed during the installation of the probe insert8into the 3D probe2—or the rotary coupling of coupling element16and screw insert116does not require any laborious screw connection operation such as is required in the case of the 3D probe from WO 02/103282 A1—with its centering element and threaded rod—and thus allows an easy and quick exchange or quick and easy installation of the probe insert8in the 3D probe2.

The following description, which relates specifically toFIGS.5-6pertains to a 3D probe insert/tip8with rotary coupling for a 3D probe2with screw insert116as “clip.”

Again, expressions used here, such as axial and radial, are to be understood—unless explicitly defined otherwise—as being in relation to the measuring axis82of the 3D probe2.

FIG.6(in the three differently rotated views) shows this alternative screw insert116in detail.

The probe insert8and the coupling element16are of identical form in relation to the embodiment described above (according toFIGS.1to4); the coupling arm/measuring shaft80and the screw insert116also substantially correspond to the above-described embodiment, in particular as regards the rotary coupling of coupling element16and screw insert116.

The embodiment of the probe lever described below (according toFIGS.5to6) has differences—in relation to the above-described probe lever6(according toFIGS.1to4)—“only” with regard to the retention of the screw insert16in the coupling arm/measuring shaft80.

Owing to the substantial correspondence of the two embodiments, the description of identical elements in both embodiments will be omitted for the sake of simplicity here (below)—and, in this regard, reference will be made to the statements relating to the embodiment described above. In particular, identical parts/components and functions are denoted by the same reference designations in the drawing figures.

As shown inFIGS.5and6, the alternative screw insert116provides a radially resilient structure148on the outer surface146of the screw insert116, which structure is formed there in the region of the first connecting/coupling region118.

Here, as illustrated inFIG.6in particular, said axially resilient structure148is formed by means of—in this case three—spring clamp elements150(“clip”).

As is also then shown inFIG.5, on the inner surface92of the recess90in the coupling arm/measuring shaft80, in which recess the screw insert116is received, there is formed a (detent engagement) structure94—in this case in the form of a radially encircling groove96on the inner surface92of the recess90in the coupling arm/measuring shaft80—in which groove96said radially resilient structure148or the spring clamp elements150can engage with detent action.

By means of these simple structural elements—of radially resilient structure148or spring clamp elements150of the screw insert116and (detent engagement) structure94or groove96of the coupling arm/measuring shaft80—it is thus possible for the screw insert116to be received and held securely in the coupling arm/measuring shaft80in a simple manner.

The following description relates specifically toFIGS.7-8and pertains to a 3D probe insert/tip8with coupling elements16braced in the coupling arm/measuring shaft80.

Once more, expressions used here, such as axial and radial, are to be understood—unless explicitly defined otherwise—as being in relation to the measuring axis82of the 3D probe2.

FIGS.7and8show—in sectional illustrations—embodiments of above-described coupling elements16(received in the coupling arm/measuring shaft80) which furthermore provide bracing by means of their surfaces in the coupling arm/measuring shaft80or in the recess90of the coupling arm/measuring shaft80(said coupling elements16, like the coupling arms/measuring shafts80that receive them, may be or are otherwise designed in accordance with the embodiments described above).

For this purpose, as illustrated inFIGS.7and8, such coupling elements16have a subsection38, the outer circumference of which is of non-circular cross section. This non-circular con Figuration is, as shown inFIGS.7and8(in both cases), formed by regions50,52situated radially further to the inside and radially further to the out-side.

This “non-circular” subregion38is in this case arranged on the respective coupling element (as perFIG.7andFIG.8) between the planar abutment36and the journal (24a) which forms the first connecting/coupling region18(cf. for exampleFIG.2).

FIG.7shows a coupling element16in the case of which—to form the non-circularity or the regions50,52situated radially further to the inside and radially further to the outside—the outer circumference of the subregion38has, in cross section, three circular arcs54which are connected to one another and which are “relatively flat”, that is to say whose radii of curvature are greater than half of the circle diameter.

FIG.8shows a similar coupling element16, in the case of which the outer circumference of the subregion38in cross section connects three circular arcs54(of a common circle, that is to say with equal radius) via straight chords56respectively situated in between.

Correspondingly to these “non-circular” subregions38of the coupling elements16, correspondingly complementary “non-circular” structures are formed on the inner surfaces92of the recesses90in the coupling arms/measuring shafts80. That is to say that, in that case, too, these have regions50,52situated radially further to the in-side and radially further to the outside.

FIG.7shows a coupling arm/measuring shaft80, the recess90of which has, on the inner surface92thereof in cross section—in somewhat larger form (in relation to the subregion38of the coupling element16)—three interconnected “relatively flat” circular arcs54(, such that—in the case of a “concentric” arrangement/orientation of coupling arm/measuring shaft80and coupling element16—a degree of play (required for the relative rotation (bracing) forms/can form between coupling arm/measuring shaft80and coupling element16).

FIG.8shows a coupling arm/measuring shaft80, the recess90of which has, on its inner surface92in cross section, three interconnected circular arcs54—three ra-dii of identical circles with offset central points (starting points of the circular arcs54marked by circles K).

In both cases according toFIGS.7and8, it is thus the case that regions50,52situated radially further to the inside and radially further to the outside form—on the outer surface of the subsection38of the respective coupling element16and on the inner surface92of the recess90of the respective coupling arm/measuring shaft80.

It is thus then possible, if the coupling element16is to be received in the coupling arm/measuring shaft80, for said coupling element to be pushed into the recess90thereof and then rotated—relative to the coupling arm/measuring shaft80. Here, if the regions50,52, situated radially further to the outside, of the coupling element16or in/of the subsection38of the coupling element16abut against the regions50,52, situated radially further to the inside, of the coupling arm/measuring shaft80or in the recess90of the coupling arm/measuring shaft80or on the inner surface92of the recess90of the coupling arm/measuring shaft80, then the coupling element16and the coupling arm/measuring shaft80are braced relative to one another.

The following description refers specifically toFIGS.9-11and pertains to a 3D probe insert/tip8with rotary coupling for a 3D probe2.

Needless to say, expressions used here, such as axial and radial, are to be understood—unless explicitly defined otherwise—as being in relation to the measuring axis82of the 3D probe2.

FIG.10shows a detail of said 3D probe2with alternative screw insert116.

FIG.11shows a section—along the section line denoted by F-F inFIG.9in the case of said 3D probe2with alternative screw insert116.

The probe insert8and the coupling element16are of identical form in relation to the embodiment described above (according toFIGS.1to4); the coupling arm/measuring shaft80and the screw insert116also substantially correspond to the above-described embodiment, in particular as regards the rotary coupling of coupling element16and screw insert116(thread segments28,126(cf.FIGS.2and3).

The embodiment of the probe lever6described below (according toFIGS.9to11) has differences—in relation to the above-described probe lever6(according toFIGS.1to4)—“only” with regard to the retention of the screw insert16in the coupling arm/measuring shaft80and the axial planar abutment of the axial planar abutment surface36of the coupling element16.

Owing to the substantial correspondence of the two embodiments, the description of identical elements in both embodiments will be omitted for the sake of simplicity here (below)—and, in this regard, reference will be made to the statements relating to the embodiment described above (as perFIGS.1to4). In particular, identical parts/components and functions are denoted by the same reference designations in the drawing figures.

As shown in particular inFIGS.9and10, the alternative screw insert116provides on the screw insert116—there at the other end of the recess124that bears the thread segments126or the internal thread components128—a bore152which forms the second connecting/coupling region120and which has an inserted (hexagonal socket) screw122.

By means of this (hexagonal socket) screw122—and its external thread134—the screw insert116is screwed into the coupling arm80(into the internal thread88thereof) (cf.FIGS.9and10).

Furthermore, as is also shown inFIGS.9and10, the end at the other side of the screw insert116, which end has the bore152and the screw122, forms a radially extending abutment surface136for the axial abutment against the counterpart surface144on the coupling arm80.

Furthermore, here, the screw insert116provides a substantially cylindrical subsection138for radial centering in the coupling arm80.

As is also illustrated byFIGS.9and10, the radially extending abutment surface36, which is directed in the direction of the journal (24a) that bears the thread segments28or the external thread components30, of the radially outwardly extending flange-like projection42of the coupling element16is supported here on a counterpart surface44on the screw insert116(planar abutment—see above) (cf. according to the embodiment as perFIGS.1to4, this planar abutment36/44took place between coupling element16and coupling arm80).

(Further) planar abutment between screw insert116and coupling arm80then takes place, as shown inFIGS.9and10, via a planar abutment surface156on the screw insert116and a counterpart surface154on the coupling arm80.

In short, and in descriptive terms, where, according to the embodiment of the probe lever6as perFIGS.1to4, the planar abutment takes place by means of a flange-like structure158—provided integrally on the coupling arm80—between coupling element16and coupling arm80(cf. planar abutment44/36as perFIG.4), it is the case in the embodiment of the probe lever6as perFIGS.9to11that this flange-like structure158is formed integrally on the screw insert116, whereby, firstly, first planar abutment44/36occurs between coupling element16and screw insert116and, secondly, second planar abutment154/156occurs between screw insert116and coupling arm80.

Here, too, it is thus possible by means of these simple structural elements on the screw insert116for the screw insert116to be received and held securely in the coupling arm/measuring shaft80in a simple manner.

Regardless of above-described exemplary embodiments, in particular those according toFIGS.1to4,FIGS.7to8andFIGS.9to11, respectively, elements of an exemplary embodiment may be combined with elements of another exemplary embodiment.

For example, the screw insert116with separate screw122(as per the embodiment according toFIGS.9to11) and abutment surfaces44/36(as per the embodiment according toFIG.4) may be combined with one another in the case of a further probe lever6of a 3D probe2.

In the case of this combined embodiment, the screw insert116may also wobble somewhat if the screw112is not fully tightened, such that the centering of the coupling arm116is not influenced.

Although the invention has been illustrated and described in more detail using the preferred exemplary embodiments, the invention is not restricted by the disclosed examples and other variations can be derived therefrom without de-parting from the scope of protection of the invention.

The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention:2Probe measuring apparatus, 3D probe4Housing6Probe lever, probe arm8Probe insert, probe tip10Probe ball (probe reference point) (welded to steel pin12)12(Steel) pin (adhesively bonded in ceramic sleeve14)14(Ceramic) sleeve (screwed and adhesively bonded in coupling element16)16Coupling element (for quick-action coupling probe insert8—coupling arm/measuring shaft80, coupled to screw insert36)18First connecting/coupling region, first screw region (coupling to screw insert116)20Second connecting/coupling region, second screw region (connection to probe insert/probe tip8or ceramic sleeve14)(24a) (Threaded) journal (at one end) (thread segments28thereon)24bFurther (threaded) journal (at the other end) (with recess (26b) for sleeve14)(26a) Further recess (in the first connecting region18for internal thread34for screw connection to previous threaded rod)(26b) Recess (in the second connecting region20for sleeve14)28Thread segment (on the journal (24a) for (quick-action) coupling to screw insert36)30Depression, partial thread turn, external thread com-ponent (in the thread segment28)32Discontinuity, recess (between thread segments28)34Internal thread (in recess (26a) in the journal (24a) for screw connection to previous threaded rod)36Abutment surface for axial planar abutment (axial planar abutment surface)38Substantially cylindrical subsection (for radial centering)40Bead42Flange-like projection (with planar abutment)44Counterpart surface (on coupling arm80/on screw insert116for planar abutment surface36)46Fluting48Fluting50Region (of the non-circular structure) situated radially further to the inside52Region (of the non-circular structure) situated radially further to the outside54Circular arc56Chord60Outer surface (of the journal (24a)62Radial circumferential direction68Pitch profile70Inner surface (in recess124)80Coupling arm, measuring shaft82Measuring axis84Direction of probe tip86Universal/ball joint88Internal thread90Recess (in the coupling arm80for coupling element16and screw insert116)92Inner surface (in recess90(with non-circular structure)94(Detent engagement) structure96Radially encircling groove116Screw insert (for quick-action coupling probe insert8—coupling arm/measuring shaft80, coupled to coupling element16)118First connecting/coupling region, first screw region (coupling to coupling element16)120Second connecting/coupling region, second screw region (connection to coupling arm/measuring shaft80)External thread (for screw connection to coupling arm/measuring shaft80)122(Threaded) journal or screw (with external thread134for screw connection to/in the coupling arm/measuring shaft80)124Recess (at/in the first connecting region118for thread segments126)126Thread segment (for (quick-action) coupling to coupling element16)128Depression, partial thread turn, internal thread com-ponent (in the thread segment126)130Discontinuity, recess (between thread segments126)132Reduced-diameter intermediate region (between the first and the second connecting/coupling region118,120(flexibility)134External thread136Abutment surface for axial abutment (axial abutment surface)138Substantially cylindrical subsection (for radial centering)140Outer surface (of the journal122or of the screw122)142Flange-like projection (with abutment), abutment144Counterpart surface (on the coupling arm80for abutment surface136)146Outer surface of the screw insert116in the region of the first connecting/coupling region148Radially resilient structure150Spring clamp elements152Bore154Counterpart surface (on the coupling arm80for planar abutment surface156)156Abutment surface (on screw insert116for axial planar abutment (axial planar abutment surface)216Coupling assembly, rotary couplingF-F Section