Locking system for a mechanical component

Abstract

A platform has a support surface for a mechanical component and is provided with at least two locking seats extending about respective axes perpendicular to the support surface and opening on the support surface. The locking seat is adapted to coaxially receive a respective locking pin fixed to the mechanical component and provided with a respective circumferential groove adapted to be restrictively engaged by a retaining means associated with the platform. The retaining device comprises a retaining element supported by the platform such that the retaining element is rotatable about an axis of rotation perpendicular to the support surface for rotation under control of the actuating device between a release position and a locking position, and the retaining element is provided with a peripheral edge, the outer peripheral edge has a profiled surface at each of the locking seats, the profiled surface having a profile to restrictively engage the circumferential groove when the retaining element is in the locked position and disengage from the circumferential groove when the retaining element is in the released position.

Description

Technical Field

[0001] The invention relates to a locking system for a mechanical component. Background Art

[0002] In this specification, the term "machine component" is generally understood to be a fixture (such as a vise, etc.) used to fix a workpiece suitable for machining on a machine tool and directly the workpiece to be machined. However, in order to simplify the description, reference will be made to the first case and more specifically to the locking of the vise.

[0003] As is known, a workpiece designed to be machined on a machine tool can be secured to a vise which in turn can be mounted in a fixed position in the working area of ​​the machine tool by means of a locking system.

[0004] Typically, the locking system may comprise a platform provided with a plurality of locking seats, typically four locking seats arranged in a square pattern. The locking seats are adapted to coaxially receive corresponding locking pins, which are fixed in the same square arrangement directly to the vise or more usually to a fixing plate which serves as an engagement piece and to which the vise is fixed.

[0005] Each locking pin is provided with a circumferential groove adapted to be engaged by a respective retaining means associated with the platform.

[0006] In known locking systems, the retaining device generally comprises a plurality of locking inserts slidably received in respective seats of the platform. Each locking insert can slide radially relative to a respective one of four locking pins between a locking position, in which the locking insert engages a groove of the locking pin, and a release position, in which the locking insert releases the locking pin, thereby allowing the locking pin to be inserted into or extracted from the respective locking seat.

[0007] The locking insert is actuated by a corresponding actuating element which, in known locking systems, can, for example, comprise a plurality of sliding transmission elements which are interconnected by inclined planes and which can move under the control of a screw actuator, a hydraulic piston transmission, or a rotating cam acting on the locking insert.

[0008] Due to the fact that a plurality of sliding mechanical elements form the retaining device, the known locking systems have the disadvantage of being particularly susceptible to play and to wear, which has a negative impact on the positioning accuracy and therefore requires frequent maintenance or replacement interventions. Summary of the invention

[0009] The object of the present invention is therefore to provide a locking system for a mechanical component which is less prone to play and wear than known systems, thereby increasing positioning accuracy and reducing the need for maintenance or replacement interventions.

[0010] This and other objects of the invention which will become more apparent from the following description are achieved by a locking system having the characteristics described herein, while the dependent claims define other advantageous characteristics of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The invention will now be described in more detail with reference to some preferred but non-exclusive embodiments shown by way of non-limiting examples in the accompanying drawings, in which:

[0012] Figure 1 is an exploded perspective view of a locking system according to the present invention;

[0013] Figure 2 is an assembled perspective view of a locking system according to the present invention;

[0014] Figure 3 yes Figure 1 A partial cross-sectional plan view of the locking system in FIG.

[0015] Figure 4 yes Figure 1 A side elevation view of the locking system in FIG.

[0016] Figure 5 It is taken along plane VV Figure 3 sectional view of;

[0017] Figure 6 It is taken along plane VI-VI Figure 3 sectional view of;

[0018] Figure 7 It is taken along plane VII-VII Figure 3 sectional view of;

[0019] Figure 8 It is taken along plane VIII-VIII Figure 4 sectional view showing the locking system according to the present invention in an initial operating configuration;

[0020] Fig. 9 yes Figure 8 A magnified view of the details in the

[0021] Fig.10 is similar to Figure 8 , showing the locking system according to the invention in a second operating configuration;

[0022] Fig.11 yes Fig.10 A magnified view of the details in the

[0023] Fig.12 is a schematic diagram of elements of a locking system according to an alternative embodiment of the present invention;

[0024] Fig.13 yes Fig.12 An enlarged side elevation of the detail in. DETAILED DESCRIPTION

[0025] refer to Figures 1 to 11 , reference numeral 10 generally designates a locking system for a mechanical component according to the present invention.

[0026] The locking system 10 comprises a platform 12 having a support surface 14 on which a machine component is adapted to be supported, such as a vise 16 (only in the case of a vise 16) for securing a workpiece designed to be machined on a machine tool. Figure 4 , Figure 5 and Figure 7 The vise 16 (or other machine component) may be supported directly on the support surface 14 or (as in the example shown and described herein) by interposing a fixing plate 18 (also only in FIG. Figure 4 , Figure 5 and Figure 7 ) and supported on a support surface, the fixing plate acting as a joint.

[0027] The platform 12 is provided with a plurality of locking seats 20 , in particular four locking seats 20 arranged in a square in the example described here, which extend about respective axes perpendicular to the support surface 14 and open towards the support surface.

[0028] The locking seats 20 are suitable for coaxially receiving corresponding locking pins 22 (of a type known per se) which are fixed at right angles to the fixing plate 18 in the same square arrangement.

[0029] Each locking pin 22 has a generally cylindrical profile and is provided with a circumferential groove 24 adapted to be captively engaged by retaining means 26 associated with the platform 12 .

[0030] refer to Figure 6 The circumferential groove 24 is axially defined between a first frustoconical surface 24' and a second frustoconical surface 24", the first frustoconical surface facing the fixing plate 18 and adapted to be engaged by the retaining means 26, and the second frustoconical surface coaxially facing the first frustoconical surface.

[0031] The retaining device 26 according to the present invention includes a retaining element 28, which is supported by the platform 12 so that the retaining element can rotate around a rotation axis A perpendicular to the supporting surface 14, so that the retaining element can rotate between a release position and a locking position under the control of an actuating device 29, and the retaining element is provided with a peripheral edge 30, which has a molded surface 33 at each locking seat 20, the contour of which engages the circumferential groove 24 of the locking pin 22 in a restrictive manner when the retaining element 28 is rotated into the locking position, and disengages from the circumferential groove 24 when the retaining element 28 is rotated into the release position.

[0032] In the embodiment described herein, the retaining element 28 has a substantially annular profile and is housed in a cavity 32 of the platform 12 , which has a complementary substantially annular profile and communicates with the four locking seats 20 .

[0033] Specifically, the retaining element 28 is rotatably mounted on a cylindrical portion 12 a of the platform 12 which defines an inner annular contour of the cavity 32 .

[0034] Reference now Fig. 9 and Fig.11 Each of the four molding surfaces 33 is provided with a contact portion 33a, which is defined between a first end 33a' and a second end 33a" and has an outer contour gradually away from the rotation axis A, so that when the retaining element 28 is in the locked position, the contact portion engages the circumferential groove 24 at an intermediate position between the first end 33a' and the second end 33a", and when the retaining element 28 is in the released position, the contact portion disengages from the circumferential groove 24.

[0035] In the embodiment described here, the contact portion 33a advantageously has an arc-shaped profile with a concave surface facing inwards (ie towards the axis of rotation A).

[0036] Furthermore, in the embodiment described here, the peripheral edge 30 of the retaining element 28 has a generally cylindrical profile, and each profiled surface 33 forms a recess of the cylindrical profile. Specifically, in this embodiment, the contact portion 33a is included between a first end portion 33b and a second end portion 33c, the first end portion advantageously having a concave outwardly arc-shaped profile and a diameter greater than or equal to the diameter of the locking pin 20, and the second end portion advantageously having a concave outwardly arc-shaped profile and a diameter less than the diameter of the locking pin 20.

[0037] Preferably, the diameter of the contact portion 33a is larger than the diameter of the first end portion 33b.

[0038] When the retaining element 28 is in the released position, each profiled surface 33 faces the corresponding locking seat 20 and is located so as not to interfere with the profile of the locking pin 22 ( Figure 8 and Fig. 9 ).

[0039] When the retaining element 28 is in the locked position, each profiled surface 33 enters the corresponding locking seat 20 and engages the first frustoconical surface 24′ ( Fig.10 and Fig.11 ).

[0040] Preferably, reference Figure 6 Each of the molding surfaces 33 has a chamfered edge at least on the side facing the first truncated cone surface 24' so that the first truncated cone surface and the first inclined surface 33' of the contact portion 33a having the same inclination therewith are engaged.

[0041] Preferably, and again with reference to Figure 6 Each of the four molding surfaces 33 also has a chamfered edge on the side facing the second truncated cone surface 24 ″ so that the second truncated cone surface faces the second inclined surface 33 ″ of the contact portion 33 a having the same inclination as that of the contact portion 33 a.

[0042] Reference now Figures 7 to 11 In the embodiment described herein, the actuating device 29 comprises a rotary actuator 36 supported by the platform 12 so that it can rotate about the actuation axis B. In this embodiment, the rotary actuator 36 has a generally cylindrical profile and is rotatably inserted into a through hole 38 of the platform 12, which extends about the actuation axis B. Moreover, in this embodiment, the actuation axis B extends radially relative to the rotation axis A. The rotary actuator 36 has an inner end 36a, facing the peripheral edge 30 of the retaining element 28, and an outer end 36b, shaped to allow the rotary actuator 36 to be manually locked. In this embodiment, the outer end 36b of the rotary actuator 36 has a hexagonal seat 39 that can be engaged by a corresponding hexagonal locking wrench (not shown). The inner end 36a of the rotary actuator 36 has an eccentric protrusion 36c, which engages in place with a corresponding seat 40 on the retaining element 28, which seat is spaced from the rotation axis A. In this embodiment, the seat 40 is provided on the peripheral edge 30 of the retaining element 28 between the two profiled surfaces 33 defining the recess.

[0043] The rotary actuator 36 is held in the through hole 38 by an externally threaded ring 42, in which a sealing ring 44 is inserted. The ring 42 is screwed onto the correspondingly threaded outer portion 38a of the through hole 38.

[0044] One of the two axial ends of the cavity 32 is defined by a cover 46 that is screwed onto the cylindrical portion 12 a of the platform 12 by a plurality of screws 47 .

[0045] A first annular gasket 48 , which is housed in an annular groove 50 of the retaining element 28 , is interposed between the cover 46 and the retaining element 28 .

[0046] A second annular washer 52 is interposed between the face of the platform 12 opposite the support surface 14 and defining the other axial end of the cavity 32 , and is housed in a second annular groove 54 of the retaining element 28 .

[0047] The surface of the cover 46 facing the cavity 32 has four additional annular grooves 56 aligned with the locking seats 20 and housing corresponding additional annular washers 58 against which the locking pins 22 are adapted to abut.

[0048] The locking system operates Figures 8 to 11 Shown in detail.

[0049] When the retaining element 28 is in the released position, the fixing plate 18 on which the vise 16 is mounted can rest on the support surface 14 of the platform 12, and the locking pins 22 are free to enter the corresponding locking seats 20 ( Figure 8 and Fig. 9 ). In this configuration, the profiled surface 33 faces the corresponding locking seat 20 but does not interfere with the passage of the locking pin 22 .

[0050] To lock the fixing plate 18 to the platform 12, the rotary actuator 36 is rotated using a hexagonal wrench (not shown), thereby causing the retaining element 28 to be moved from the retaining element 28 by engagement of the eccentric protrusion 36c in the seat 40 of the retaining element 28. Figure 8 and Fig. 9 Rotate to the release position in Fig.10 and Fig.11 in the locked position.

[0051] In the locked position, the first inclined surface 33' of the contact portion 33a of the profiled surface 33 restrictively engages the first frustoconical surface 24' of the recess 24 of the locking pin 22, thereby clamping the fixing plate 18 against the support surface 14 of the platform 12. The arc-shaped profile of the contact portion 33a causes the ratio between the clamping force and the rotation angle of the retaining element 28 to gradually increase as the rotary actuator 36 is tightened.

[0052] Of course, in order to release the mechanical part, it is sufficient to turn the rotary actuator 36 in the opposite direction to return the retaining element 28 to its release position.

[0053] Practice has also shown that the present invention has fully achieved the intended purpose and objectives.

[0054] In particular, the locking system according to the invention comprises a single rotation retaining element which directly engages all locking pins, i.e. without intermediate sliding elements. This makes the locking system according to the invention less susceptible to wear and less susceptible to play than known systems, thereby improving positioning accuracy and reliability.

[0055] Fig.12 The retaining element 128 according to an alternative embodiment of the present invention is schematically shown in a release position (solid line) in which the profiled surface 133 does not engage the groove 124 of the locking pin 122, and in a locking position (dashed line) in which the profiled surface 133 engages the groove 124. In this alternative embodiment, instead of the cylindrical profile profiled in the form of a recess in the previous embodiment, the retaining element 128 is cross-shaped, and the profiled surfaces 133 are formed at the ends of the four arms 135 of the cross. Furthermore, in this alternative embodiment, the profiled surface 133 has a straight profile inclined relative to the radius connecting the rotation axis A' to the axis of the locking pin 122, but the profiled surface may also have an arc-shaped profile with the concave surface facing inwards, as in the example of the contact portion of the profiled surface in the previous embodiment.

[0056] Some preferred embodiments of the present invention have been described, but those skilled in the art will of course make various modifications and variations within the scope of the claims.

[0057] For example, those skilled in the art will readily appreciate that the system described herein can be used to lock any fixture or workpiece directly, or by inserting a retaining plate as in the example described herein with respect to locking a vise.

[0058] Furthermore, variations obvious to a person skilled in the art are that the locking system can be adapted to lock two, three, five or more pins, depending on specific requirements.

[0059] Of course, alternative actuation means for actuating the rotation of the retaining element may be provided, such as a worm gear mechanism engaging with a toothed portion of the retaining element, a lever system or other similar locking system.

[0060] The described engagement means may also be modified in such a way that the rotary actuator is provided with an eccentric projection engaging a seat of the retaining element spaced apart from the axis of rotation. For example, in principle, the actuation axis about which the rotary actuator rotates may be parallel rather than radial relative to the axis of rotation of the retaining element, so as to engage with its eccentric projection a seat provided on one of the faces axially defining the retaining element in a position axially offset relative to the axis of rotation.

[0061] Importantly, in the examples described, the contact portion of the shaped seat has an arc-shaped profile with the concave surface facing inwards (first embodiment) or a straight profile (second embodiment). Of course, other suitable curved profiles can be easily designed by a person skilled in the art, for example in order to change the progressive course of the force applied during locking.

Claims

1. A locking system for a mechanical component, comprising a platform (12) having a support surface (14) for a mechanical component (16, 18) and provided with at least two locking seats (20), the locking seats extending around respective axes perpendicular to the support surface (14) and opening on the support surface (14), the locking seats (20) being suitable for coaxially receiving respective locking pins (22), the locking pins being fixed to the mechanical component (16, 18) and provided with respective circumferential grooves (24), the circumferential grooves being suitable for restrictive engagement by retaining means (26) associated with the platform (12), characterised in that The retaining device (26) includes a retaining element (28), which is supported by the platform (12) so that the retaining element can rotate about a rotation axis (A) perpendicular to the supporting surface (14) to rotate between a release position and a locking position under the control of an actuating device (29), and the retaining element is provided with a peripheral edge (30), and the peripheral edge has a molded surface (33) at each locking seat in the locking seat (20), and the molded surface has a contour to restrictively engage the groove (24) when the retaining element (28) is in the locking position, and disengage from the groove (24) when the retaining element (28) is in the release position.

2. The locking system according to claim 1, characterized in that: Each of the molding surfaces (33) is provided with a contact portion (33a), which is defined between a first end (33a') and a second end (33a"), and has an outer contour that gradually moves away from the rotation axis (A) so as to engage the groove (24) at an intermediate point between the first end (33a') and the second end (33a") when the retaining element (28) is in the locked position.

3. The locking system according to claim 2, characterized in that: The contact portion (33a) has an arc-shaped profile with a concave surface facing inwards.

4. The locking system according to claim 2, characterized in that: The peripheral edge (30) generally has a cylindrical profile, and each of the molding surfaces (33) forms a recess of the cylindrical profile, the contact portion (33a) being included between a first end portion (33b) and a second end portion (33c) of the recess.

5. The locking system according to claim 4, characterized in that: The first end portion (33b) has an arc-shaped profile with a concave surface facing outward, and the diameter of the first end portion is greater than or equal to the diameter of the locking pin (22).

6. The locking system according to claim 4, characterized in that: The second end portion (33c) has an arc-shaped profile with a concave surface facing outward, and the diameter of the second end portion is smaller than the diameter of the locking pin (22).

7. The locking system according to claim 4, characterized in that: The contact portion (33a) has an arc-shaped profile with a concave surface facing inward, and the diameter of the contact portion is larger than the diameter of the first end portion (33b).

8. The locking system of claim 2, wherein: The groove (24) is axially defined between a first truncated conical surface (24') and a second truncated conical surface (24"), the first truncated conical surface facing the mechanical part (18) and suitable for being engaged by the retaining device (26), characterized in that each of the molding surfaces (33) has a chamfered edge at least on the side facing the first truncated conical surface (24') so that the first truncated conical surface and the first inclined surface (33') of the contact portion (33a) having the same inclination as the first truncated conical surface engage.

9. The locking system according to claim 1, characterized in that: The actuating device (29) comprises a rotary actuator (36) supported by the platform (12) so that the rotary actuator can rotate about an actuating axis (B), and the rotary actuator is provided with an eccentric protrusion (36c) which engages a corresponding seat (40) of the rotating retaining element (28) spaced apart from the rotation axis (A), and the rotary actuator (36) can be manually actuated to rotate the retaining element (28) between the locking position and the releasing position by engaging between the eccentric protrusion (36c) and the seat (40).

10. The locking system according to claim 9, characterized in that The actuation axis (B) extends radially relative to the rotation axis (A), and the seat (40) is arranged on the peripheral edge (30) of the retaining element (28).

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