MXPA00000796A - Tool coupling system for machine tools - Google Patents

Abstract

An improved coupling system for lockably coupling machine tool components is provided that includes a male coupling, a female coupling having an axis, a pair of opposing jaw members having lock surfaces for engaging ledge surfaces in the male coupling when the jaw members are moved apart, and a drive train having first and second drive spheres for simultaneously moving proximal and distal ends of the jaw members apart. The drive spheres engage ramps on the inner surfaces of the jaw members that have cylindrical profiles to provide lenticular contact between the spheres and the jaw members. Cam and follower surfaces are provided between the jaw members and one of the male or female couplings to enhance the locking force between the couplings. The invention provides a more rigid coupling between the male and female components by providing two locking spheres that operate in tandem to simultaneously spread the distal and proximal ends of the jaw members apart.

Description

SYSTEM. TOOL COUPLING FOR TOOL MACHINES BACKGROUND OF THE INVENTION This invention relates generally to a system for coupling machine tools and relates specifically to an improved coupling system of the type having a clamping mechanism of the jaw type where the improvement comprises a driving rail that distributes simultaneously the proximal as well as distal ends of the jaws to provide a more rigid coupling. Coupling systems for interconnecting machine tools are well known in the prior art. Such coupling systems include a frustoconical, hollow male component that is part of the tool. The male component is joined to a frusto-conical opening in a female component that is typically part of an axis for rotating the tool. The taper of both frustoconical components typically has a slope of approximately 1-10 with respect to the longitudinal axis of the tool. Such a slope provides an interference coupling on the center, rigid, when the components are pulled together by means of a clamping mechanism placed inside the female aperture.

A variety of mechanisms are available so far to hold together the male and female components of the prior art coupling systems. In some of these mechanisms, the female component includes mobilization that moves radially to engage connection openings in a complementary manner in the walls of the male component. When moving radially outwardly, the locking spheres function to secure and pull the frusto-conical body of the male tool towards the opening of the female component. An axially slidable locking bar, having cam surfaces radially forces the locking spheres outwardly towards the connecting openings. In other types of mechanisms, the female openings include a radially expanding immobilization piston which can extend into the hollow interior of the male frustoconical component. The immobilization piston may include two or more radially moving fingers that engage the openings in the wall of the male component before forcing the wedge of the male component toward the opening of the female component. Although both of those general types of coupling systems of the prior art have shown themselves • Even if they are effective for their intended purpose, the systems manufactured by different manufacturers are unfortunately not interchangeable. In this way the end user of a tooling system has been forced, until recently, to choose between a particular type of tool and a patented or other coupling system. To remedy this problem, the German government in 1987 standardized the dimensions of the envelope so that such systems would have to comply with a proclamation entitled "DIN 69890". However, this proclamation does not standardize the aspect ratio or type of coupling mechanism that had to hold the male and female frustroconical components together. The standardization specifications that allowed such interchangeability did not occur in Germany until the issuance of a final proclamation entitled "DIN 69893" in 1993, in which the dimensions of the tapered area of the male and female components that would secure the components together are fixed. This last proclamation also specified that the male component must have an annular rim circumscribing its interior that defines a driving surface. By implication, the female component must have a member with a cam surface to engage the male driving surface to immobilize the two components together. The standardized coupling system specified in DIN 96893 is already being manufactured by several tool companies based in Germany, whose systems are being sold to several of the leading German automakers. The growth of the implementation of DIN 69893 in Germany and elsewhere probably results in the adoption of those same specifications internationally. DIN 69893 does not specify what form any cam members should take on the female component, or what drive mechanism must be used to move those cam members in engagement with the driving surface within the male component, a particularly successful design employs a pair of opposed jaw members placed inside the female coupling. Each of the jaw members includes legs on its proximal end which slides in a cavity complementary in shape to the inner diameter of the female coupling to rotatably mount the jaw members. The distal end of each of these members includes a cam surface which interacts with the driving surface on the male coupling when the jaw members are rotatably distributed, spaced apart, to immobilize the two components together. The drive mechanism for this particular design includes a single locking sphere positioned between the distal ends of the opposing jaw members. An immobilization bar axially moves the locking sphere towards the proximal ends of the jaw members, so that the mobilization sphere distributes the proximal ends of these separated members in immobile engagement with the conducting surface in the wedge-shaped manner. male coupling. Such a clamping mechanism advantageously provides a rigid coupling by means of a relatively simple part that can be easily replaced when worn. The use of a sphere that floats freely as a wedging element in this design is particularly advantageous since wear on the sphere due to its wedging action does not occur in the same place, but is distributed on the surface of the sphere, giving so the life of the mechanism. Although such a drive mechanism has proven effective in rigidly immobilizing a male and female coupling together, the applicant has observed several areas where the operation of this mechanism can be improved. For example, the rotational movement between the legs of the jaw members and their respective cavities within the female coupling results in a smaller contact area than that of the jaw members and the inner surfaces of the male and female coupling than what would occur if the jaw members could be evenly distributed, separated, without such rotating movement. The rotational action of the jaw members also requires that the cam surfaces and legs be manufactured to greater tolerances than would be necessary if all the jaw members could be distributed, separated, uniformly throughout. Clearly, there is a need for an improved coupling system of the type employing opposite jaw members for immobilisably interconnecting a male coupling to a female coupling having a drive mechanism capable of distributing the proximal as well as distal ends of the coupling. the jaw members to overcome the aforementioned drawbacks associated with the prior art systems. Ideally, such a drive system will be of cheap manufacture, easily adaptable to existing systems and reliable in its operation. Finally, such an improved system should retain all the advantages associated with drive mechanisms that use spherical components to distribute, separately, by wedging a pair of locking jaws.

BRIEF DESCRIPTION OF THE INVENTION Generally speaking, the invention is an improved coupling system for immobilisably coupling machine tool components comprising a male coupling having edge surfaces, a male coupling, a pair of opposed jaw members which have proximal ends mounted movably within the female coupling, and distal ends having locking surfaces for engaging the edge surfaces of the male coupling when the jaw members are separated, and a driving rail for moving the separate jaw members, which includes first and second drive spheres and means for simultaneously moving the drive spheres in and out of engagement by wedging with the inner surfaces of the distal proximal ends of the opposing jaw members. Each of the internal surfaces of the jaw members has proximal and distal ramps for engaging the first and second drive spheres by wedging. Advantageously, each of these ramps has a cylindrical profile, so that the driving spheres are coupled to those ramps in lenticular contact. Each of the jaw members includes a leg extending orthogonally from its proximal end that can be received within a cavity of complementary shape in the female coupling to moveably adjust the jaw member within the female coupling. The means for moving the driving spheres are preferably a locking bar having first and second holes positioned orthogonally with respect to the axis of the female coupling. The drive spheres float freely within their respective holes in the locking bar, so that different surfaces of the spheres are used to couple and expand the opposing jaw members during the operational life of the coupling system, thereby avoiding areas of wear clamp located in the drive spheres. This free-floating characteristics also advantageously compensates for the normal tolerances associated with the manufacture of the jaw members and the locking surface, and the edge. The edge and immobilization surfaces of the male coupling and the jaw members may include cam and driving surfaces which cooperate to increase the locking force between the male and female couplings when the drive rail moves the jaw members apart. In an alternative embodiment, the legs and cavities of the jaw members and the female coupling may include cam and drive surface to likewise increase the locking force between the male and female couplings. This alternative embodiment is particularly useful in arrangements where the edge and locking surfaces of the jaw members and the male coupling are positioned orthogonally with respect to the axis of the female coupling. Both embodiments include a release mechanism for rotatably moving the jaw members together to separate the male and female couplings when the locking bar moves the first and second drive spheres out of the engagement by wedging with the ramp on the inner surfaces of the jaws. the gag members. This release mechanism includes a shock wall positioned on the proximal end of each of the jaw members, and opposing impact surfaces on the locking rod to rotationally move the jaw members inward after engagement with the walls. of those members. By providing a second locking sphere which moves the proximal ends of the jaw members apart, while the first sphere simultaneously moves the distal ends apart, the invention advantageously provides a more rigid connection between the male and female couplings by virtue of the increase in the surface contact between the jaws and the couplings. The elimination of a rotating action during the immobilization operation also allows some relaxation in the dimensional tolerances of the jaw members.

BRIEF DESCRIPTION OF THE DIFFERENT FIGURES Figure 1 is an exploded view of a coupling system of the invention, where partial cross-sectional views of the male and female couplings are given; Figure 2 is a plan view, in partial cross-section, of the female coupling of the system with the locking bar in an extended position and the jaw members in a retracted, non-immobilized position; Figure 3 illustrates the female coupling of Figure 2 with the locking bar in a retracted position and the jaw members in a radially extended locking position; Figure 4 is a cross-sectional side view of a first embodiment of the coupling system, wherein the annular edge of the male coupling defines a camming surface and the locking surfaces of the jaw members define driving surfaces, and Figure 5 is a side view, in cross section, of an alternative embodiment, wherein the edge surface of the body of the female coupling defines the cam surface of the distal locking surfaces and the jaw members define driving surfaces.

DETAILED DESCRIPTION OF THE PREFERRED MODE With reference now to Figure 1, where similar numbers represent similar components throughout all the different figures, the coupling system 1 of the invention generally comprises a male coupling 3, which is connected to the body of a tool 5 (indicated in shaded form), and a female coupling 7 which is attached to a support or carrier of the tool 9. The body of the tool 5 may contain a cutting tool (not shown), such as a simple cutting insert, cutter, or a drill. The support or carrier of the tool 9 can be attached to a rotary shaft or retractable extendable tool arm (not shown). As best seen in Figures 1, 2 and 3, the female coupling 7 includes a pair of movable jaw members 11 a, b and a drive rail 13 for radially extending and retracting those members in and out of engagement with a annular flange 27 placed inside the male coupling 3. Up to this point, the driving rail 13 includes a pair of driving spheres 15a, b which are removably mounted in holes present in an immobilization bar 17 extending and retracts along an axis A. As will be explained in greater detail hereinafter, such axial movement of the locking rod 17- moves the driving spheres 15a, b in engagement by wedging, simultaneously, with the surfaces of the ramp distal and proximal present along the inner surface of the jaw members lla, b, thus simultaneously biting or retracting both proximal and distal ends. to those members. The male coupling 3 is formed largely from a hollow body 21 having an external frustoconical surface 23. The base of the frustoconical surface 23 is circumscribed by an annular face 24. As will be evident hereinafter, the annular face 24 engages a ring-shaped coupling face 44 extending from the female coupling 7 when the two couplings are joined. The body 21 has a generally hollow interior 25. An annular rim 27 circumscribes the inside diameter of the body 21. This annular rim 27 defines the surface of an edge 29 which can be engaged by the distal locking surfaces present on the ends of the edges. gag members lla, b.

The female coupling 7 is formed of a cylindrical body 35 (shown in cross section in Figures 1, 2 and 3 to facilitate the understanding of the invention) that can be integrally connected to the carrier support of the tool 9. The support of Tool 9 includes an opening 36 which leads to a hollow interior 37 for receiving a base portion of the locking rod 17. The cylindrical body 39 of the female coupling 7 includes an internal frusto-conical wall 39 which is complementary in shape to the external frusto-conical surface 23 of the coupling 3. The proximal end of the inner wall 39 is circumscribed by an annular guide ring 41 which is aligned concentrically with the opening of the locking rod 36 of the tool holder 9. The proximal wall of the guide ring 41 defines a surface of annular rim 42 cooperating with the legs of the jaw members, b for joining the male 3 and female 7 couplings. An annular cavity 43 is defined between the surface of the edge 42 and the front wall of the tool holder 9 for housing the aforementioned legs of the jaw members lla, b. The proximal end of the internal frustoconical wall 39 terminates in the aforementioned annular coupling face 44. Referring again to Figures 1, 2 and 3 each of the jaw members lla, b includes an elongated body portion 47a , b which ends, at its distal end, on a tapered or inclined front surface 49a,. The distal locking surfaces 51 a, b are positioned behind the tapered or inclined front surfaces 49 a, b. Each of the jaw members lla, b terminates on its proximal end, on the legs 52a, b, which extend orthogonally from the elongate body portions 47a, b. The right-angled, distal faces of each of the legs 52a, b define proximal locking surfaces 53a, which engage against the aforementioned edge surface 42 defined by the annular guide ring 41 of the female coupling 7. Positioned on the internal surfaces of each of the jaw members lla, b are distal ramp-shaped surfaces 54a, and proximal ramp-shaped surfaces 57a, b. The distal ramp-shaped surfaces 54a, b both include a retention portion of the sphere 55 for retaining the distal drive sphere 15a when the locking rod 17 extends toward the position illustrated in Figure 2, as well as a portion of cam 56 for engaging wedge 15a when the locking rod 17 is retracted towards the position illustrated in Figure 3. The jaw members lla, b have additional proximal ramp-shaped surfaces 57a, b on the proximal ends of its internal surfaces. Referring now to Figure 4, each of these proximal ramp-shaped surfaces 57a, b also includes a retention portion of the ball 58 and a cam portion 59 for retaining and snap-fitting the proximal drive ball 15a. Advantageously, the cam portions 56, 59 of the distal and proximal ramp-shaped surfaces 54a, and 57a, b have a cylindrical profile, so that a relatively wide, lenticular contact between the surfaces of the spheres is achieved. 15a, b and the cam portions 56, 59. Such a lenticular contact prevents relatively high stresses and wear resulting from pinpoint or linear contact between the elements of the wedge. As best seen in Figure 1, the locking bar 17 includes a base portion 61 that is normally positioned within the hollow interior 37 of the tool holder 9. Although not specifically shown in any of the specific drawings, the base portion 61 is connected to an actuator, which may be a Bellville stacking washer for forcibly extending and removing the locking bar 17 along the axis A. The locking bar 17 further includes a retention portion of the sphere 63 which is characterized by being opposite the elongated cavities 64a, b. These cavities 64a, b allow the curved surfaces of the driving spheres 15a to engage the distal and proximal locking surfaces 51a, b, and 53a, b located on the inner surfaces of the jaw members lla, b. A pair of parallel through holes 65a, b extend through the distal and proximal ends of the retention portion of the sphere 63 of the locking bar 17 to receive and retain the actuation spheres 15a, b. The inner diameter of each of the holes 65a, b is slightly larger than the outer diameter of the driving spheres 15a, b to allow the spheres 15a, b to have some measure of rotational freedom. Such freedom makes, advantageously, that the spheres 15a, b have different surface couplings to the distal and proximal ramp-shaped surfaces 54a, b and 57a, b of the jaw members lla, b during the operation of the coupling system 1, avoiding thus localized areas of frictional wear on the spheres 15a, b. This freedom also allows the drive spheres to compensate for small manufacturing imperfections in the jaw members lla, b and the locking and edge surfaces. Referring now to Figures 4 and 5, both embodiments of the coupling system 1 include a release mechanism 67 for detaching the distal locking surfaces 51a, b from the jaw members lla, b from the surfaces of the edge 29 of the male coupling. 3. The release mechanism 67 is formed of a pair of tapered or inclined impact surfaces 69 a, b which engage against the tapered shock walls 71 a, b located at the proximal ends of each of the jaw members 11, b. b. The impact surfaces 69a, b and the impact walls 71a are not parallel, but are aligned 5o to 10 ° with respect to each other when the jaw members lla, b are in their radially extended position as shown in FIGS. Figures 4 and 5. Accordingly, when the striking surfaces 69a, b of the locking rod 17 are pressed against the impact wall 31a, b of the jaw members lla, b, the jaw members lla, b will rotate towards below, so that the distal and proximal locking surfaces 51a, and 53a, b are decoupled from their respective edge surfaces 29, 42. FIG. 4 illustrates a first embodiment of the invention where the distal locking surfaces of the limbs of jaw lla, b are cam surfaces 73a, b, and the edge surfaces 29 of the male coupling 3 define driving surfaces 75a, b. In contrast, the proximal locking surfaces 53a, b and the edge surface 42 of the male coupling 7 are positioned orthogonally with respect to the axis A. Accordingly, when the locking rod 16 is pulled to the right in the illustrated position, in the Figure a, the actuation spheres 15a, engage the cam portions 56, 59 of the distal and proximal ramp-shaped surfaces 54a, b; 57a, b to simultaneously radially extend both proximal and distal ends of the jaw members lla, b. The radial extension of the distal end of the jaw members lla, b causes the driving surfaces 75a, b of the jaw members lla, b to engage the cam surfaces 73a, b of the male coupling 3 such that the The body 21 of the coupling 3 is pulled further into the frustoconical cavity defined by the inner wall 39. At the same time, the proximal locking surfaces 53a, b extending from the legs 52a, b of the jaw members are orthogonally slid over the surfaces of the rim 42 of the cylindrical body 35, thereby providing the second relatively wide contact area between the jaw members lla, b and the attached couplings 3 and 7. The simultaneous radial extension of both the distal and proximal ends of the limbs of jaw lla, b, in combination with the wide contact areas between those members lla, b and couplings 3 and 7 provide the coupling more rigid than that of the devices. ive of the prior art which extend only the distal ends of the jaw members by means of a mechanical action, where each of those members rotates around its proximal leg. Figure 5 illustrates an alternative embodiment where the inner coupling cam and the driving surfaces between the jaw members lla, b and the couplings are located between the legs 52a, b of the jaw members lla, b and the edge surface "42 Specifically, the surface of the edge 42 is replaced by the frustoconical, annular cam surfaces 78a, b, while the proximal locking surfaces on the legs 52a, b have been replaced by conducting surfaces 80a. of distal locking 51a, and the surfaces of the edge 29 within the male coupling 7 are oriented orthogonally with respect to the axis A of the movement of the locking rod 17. Accordingly, when the driving spheres 15a, b are pulled towards the illustrated position in Figure 5, they react simultaneously against the cam portions 56, 59 of the surfaces in the form of a diastole and prox ramp. imal 54a, b and 57a, b for simultaneously radially extending both distal and proximal ends of the jaw members lla, b, thereby causing the proximal cam and the driving surfaces 78a, b and 80a, b to pull the male coupling 3 further into the cavity defined by the internal frustoconical wall 39 of the female coupling 7. In both cases, the wide lenticular contact between the distal and proximal ramp-shaped surfaces 54a, and 57a, b and their respective actuation spheres 15a, b in combination with the ability of the driving spheres 15a, b to move within the holes 65a, b in the retention portion of the sphere 63 of the locking bar 17 minimizes the areas of local stress between the spheres 15a, b and jaw members lla, b, thereby increasing the longevity and reliability of the coupling system 1. Although this invention has been described with respect to the preferred embodiments, the different Modifications, variations and additions will be apparent to those skilled in the art. All those modifications, variations and additions are encompassed by the scope of this invention, which is only limited by the appended claims hereof.

Claims (20)

1. CHAPTER CLAIMEDICATORÍO Having described the invention, it is considered as a novelty and, therefore, the content is claimed in the following CLAIMS: 1. A coupling system for immobilisably coupling machine tool components, characterized in that it comprises: (a) a male coupling having a cavity at a distal end that includes surfaces at the edge; (b) a female coupling having an axis, and an opening positioned along the axis to receive the distal end of the male coupling; (c) a pair of opposed jaw members having proximal ends mounted movably within the opening in the female coupling, and distal ends having locking surfaces for engaging the edge surfaces of the male coupling when the jaw members are they move apart to join the male and female couplings, both jaw members have opposite inner surfaces, and (d) a drive rail for moving the separate jaw members including first and second drive spheres, and means for simultaneously moving the first and second driving spheres in and out of engagement by wedging with the inner surfaces of the proximal and distal ends of the opposing jaw members. The coupling system according to claim 1, characterized in that the internal surfaces of the jaw members have proximal and distal ramps for engaging by wedging to couple the first and second drive spheres by wedging. 3. The coupling system according to claim 2, characterized in that each of the ramps has a cylindrical profile so that the first and second driving spheres couple the proximal and distal ramps in lenticular contact. The coupling system according to claim 1, characterized in that the means for simultaneously moving the driving spheres include a locking bar. The coupling system according to claim 4, characterized in that the locking bar includes first and second holes positioned orthogonally with respect to the axis of the female coupling, and where the first and second drive spheres float freely within the holes. 6. The coupling system according to claim 1, characterized in that the first and second driving spheres are of different diameters. The coupling system according to claim 3, characterized in that each of the ramps is inclined between 10 ° and 20 ° with respect to the axis of the female coupling. The coupling system according to claim 1, characterized in that each of the jaw members includes a leg that extends orthogonally from the proximal end that can be received within a cavity in the female coupling for movably mounting the jaw member on the female coupling. The coupling system according to claim 1, characterized in that it further comprises detachment means for moving the jaw members together to separate the male and female couplings when the locking rod moves the first and second drive spheres out of the coupling by wedging with the ramps of the opposite jaw members. The coupling system according to claim 9, characterized in that the detachment means comprise a shock wall placed on the proximal end of each jaw member which engages a collision surface placed on the immobilization bar when the bar Immobilization moves axially to decouple the drive spheres from the ramp of the jaw members. 11. A coupling system for immobilisably coupling machine tool components, characterized in that it comprises: (a) a male coupling having a cavity at a distal end and including surfaces at the edges; (b) a female coupling having an axis and an opening positioned concentrically along the shaft to receive the distal end of the male coupling; (c) a pair of opposed jaw members having proximal ends movably mounted within the opening in the female coupling, and distal ends having locking surfaces for engaging the edge surfaces when the jaw members move apart for joining the male and female couplings, both of the jaw members have opposite inner distal and proximal ramp-shaped surfaces, and (d) a driving rail for moving the separate jaw members including first and second driving spheres positioned between the opposite distal and proximal ramp-shaped surfaces, respectively, for wedging apart the distal and proximal ends of the jaw members, and a moving bar that moves axially to simultaneously move the first and second drive spheres in and out of the coupling by wedging with the surfaces in the form of a distal and proximal ramp. The coupling system according to claim 11, characterized in that the ramp-shaped surfaces have a cylindrical profile such that the driving spheres are coupled to the ramps in lenticular contact. The coupling system according to claim 11, characterized in that the first and second driving spheres are movably mounted on the mobilization bar to allow different portions of the surface of the driving sphere to be coupled to the ramps each time the drive rail is driven to put the male and female couplings. The coupling system according to claim 13, characterized in that the mobilization bar includes first and second holes positioned orthogonally with respect to the axis of the female coupling and where the first and second actuating sphere float freely within the holes. 15. The system according to claim 6, characterized in that the first and second driving spheres are of different diameters; The coupling system according to claim 11, characterized in that each of the jaw members includes a leg that extends orthogonally from the proximal end and that can be received within a cavity of a female coupling to mount in a manner mobile the jaw member on the female coupling. The coupling system according to claim 16, characterized in that the leg of each of the jaw members includes a cam surface which engages a driving surface of the cavity in the female coupling to axially retract the limbs. of jaw within the female coupling when the drive rail carries the jaw members apart to increase the locking forces between the male and female couplings. The coupling system according to claim 16, characterized in that the edge surfaces and the locking of the jaw members and the male coupling include driving cam surfaces to increase the mobilizing force between the male and female couplings. 19. The coupling system according to claim 11, characterized in that it further comprises detachment means for rotatably moving the jaw members together to separate the male and female couplings including a shock wall positioned on the proximal end of each jaw member. which engages a striking surface placed on the locking rod when the locking rod moves axially to uncouple the driving spheres from the ramp-like surfaces of the jaw members. 20. An improved coupling system for immobilisably coupling machine tool components of the type including a male coupling having a cavity at a distal end and including surfaces at the edge; a female coupling having an axis, and an opening positioned along the shaft to receive the distal end of the male coupling; a pair of opposed jaw members having proximal ends mounted movably within the opening in the female coupling, distal ends having surfaces for superimposing and engaging the edge surfaces when the jaw members move apart to join the male couplings and female, both of the jaw members have opposite inner surfaces; and a drive rail for rotatably moving the separate jaw members including a first drive sphere positioned between the inner surfaces of the distal ends of the jaw cams, and a moving bar that moves axially to move the first actuation sphere towards engagement by wedging with the internal surfaces of the distal ends of the jaw members for distributing the members apart, characterized in that the improvement comprises a second actuation sphere operably associated with the mobilization bar for coupling by wedging the inner surfaces of the proximal ends of the jaw members, so that the distal and proximal ends are distributed apart, simultaneously.