FR2770166A1 - Locator of work pieces in clamp - Google Patents

Abstract

Locator (1) of pieces (2) in a clamp (100) consists of a block (3) provided with a series of sliding wedges (4,4a,4b,4c) emerging from different faces (5a,5b,5c) of the block (3). The wedges are actuated by a liaising piece (MLA) arranged to transmit the clamping force between the wedges and the actuator causing their movements.

Description

PARTS HOLDING ELEMENT
The present invention relates to a workpiece holding element intended to allow positioning and holding of the workpieces in a clamping device, so as to allow, for example, the machining thereof. It also relates more particularly to the means for locking the clamps of the holding element as well as associated clamping devices which comprise a set of holding elements according to the invention.

 The machining of mechanical parts in large series obliges manufacturers, anxious to improve their productivity, to limit tool changes on their machine tools as much as possible in order to save time to increase their output. Therefore, there are assemblies called clamping devices intended to allow the positioning and the blocking of several identical parts to be machined on the same support.

However, such devices are not always suitable for several types of workpieces and are often specific to only one type of workpiece. In addition, they are often impractical and require numerous manipulations to ensure the positioning of said parts. The existing devices thus have drawbacks linked to their implementation and to their different construction methods.

 Thus, the present invention aims to remedy the aforementioned drawbacks by simple means, reliable, easy to implement and inexpensive. To do this, the invention has a holding element or module intended to be used in a clamping device in order to allow the positioning and blocking of several parts simultaneously in the device. The invention also makes it possible, by putting in place several kinematically connected holding elements, to position a large number of parts, and this, considerably reducing the handling operations. Furthermore, these elements can advantageously allow several different types of parts to be clamped and are easy to install.

 According to its main characteristic, the workpiece holding element in a clamping device according to the invention, intended for positioning workpieces, for example, is of the type comprising a housing body equipped with a set of movable shims of clamping emerging from different faces of said housing, said clamping blocks being linked together by connecting and actuating means intended to transmit the forces between said blocks and to cause them to move.

 According to another characteristic, the part holding element comprises blocking means intended to limit the movement of the movable wedges.

 According to an additional characteristic, the part holding element according to the invention is characterized in that the locking means limit the respective displacement of each of the movable clamping wedges between two extreme positions, a projecting position where the head of the wedge emerges from the face of the housing and a retracted position where the head of the movable wedge is set back relative to the face at the level of the latter or very slightly projecting.

 According to one embodiment of the holding element according to the invention, the blocking means are constituted by a longitudinal hollow profile disposed laterally on the wedge, intended to slide between two extreme positions around a blocking pin secured to the body.

 According to this embodiment, the mobile wedges are of cylindrical shape and the hollow profile of these is produced by a lateral flat.

 According to an alternative embodiment, the blocking pins consist of portions of rods, forced fitting in complementary internal bores orthogonal to the longitudinal axis of the wedge whose movement they limit.

 According to an additional characteristic, the retaining element comprises three movable clamping wedges of cylindrical shape arranged in a longitudinal plane of the housing, two wedges whose end located in the housing is bevelled being arranged along a longitudinal axis called sliding, while that the third perfectly cylindrical wedge is arranged along a transverse median axis orthogonal to the longitudinal axis carrying the other wedges.

 According to another characteristic of the part holding element, the connection and actuation means consist of an intermediate transmission part of cylindrical shape, disposed between the movable clamping shims along the longitudinal axis of sliding, the ends have a beveled shape complementary to that of the two beveled shims and whose diameter is less than the diameter of the clamping shims.

 Furthermore, the invention also relates to a device for clamping parts of the type comprising a set of holding elements such as those described above, said elements being kinematically connected.

 Other characteristics and advantages of the invention will emerge from the description which follows with reference to the appended drawings which are given only by way of nonlimiting examples.

 Figures 1 to 8b illustrate the preferred embodiment of the holding element.

 Figure 1 illustrates in perspective a clamping device in which several holding elements are arranged to hold a large number of workpieces.

 Figure 2 illustrates in perspective a holding element.

 Figure 3 shows the holding element in rear view.

 Figure 4 shows in side view the holding element.

 FIG. 5a illustrates in cross section along BB the holding element and its blocking means.

 Figure 5b illustrates in a view similar to Figure 5a an alternative embodiment of the locking means.

 FIG. 6 illustrates in perspective a mobile beveled clamping wedge.

 Figure 7 illustrates in perspective the connecting and actuating part.

 Figures 8a and 8b respectively illustrate in longitudinal section a movable clamping wedge in a so-called projecting position and in its withdrawn position.

 The holding element according to the invention bearing the general reference (1) is intended to position and block the workpieces (2) in a clamping device (100), as for example in a frame-type assembly such as 'illustrated in Figure 1. In this example, the clamping device allows to position a large number of parts (2) using a set of holding elements (1, la, lb, lc) using means clamping device (MS) which may consist of one or more clamping screws or bolts (101) intended to actuate several holding elements simultaneously to ensure the clamping of all the parts located in the frame. It goes without saying that the invention also relates to a clamping device (100) provided with a set of holding elements such as those described later, said elements being advantageously kinematically connected in order to reduce the number of clamping operations for the parts. .

 According to the invention, the holding element (1) comprises a body or housing (3) from which emerges a set of movable clamping wedges (4, 4a, 4b, 4c). These mobile wedges, also called holding fingers (4a, 4b, 4c), are intended to move axially so as to cooperate directly, either with the parts (2) to tighten them, or with other holding fingers belonging to another holding element disposed in the clamping device to transmit the clamping force necessary for positioning all of the parts (2) to be machined. The body (3) of the retaining element (1) is advantageously of rectangular shape and has on some of its faces (5a, 5b, 5c) an orifice (7) from which emerges a movable clamping wedge (4), as shown in Figure 2.

 According to the preferred embodiment of the holding element (1), each of the holding fingers (4a, 4b, 4c) advantageously moves along its longitudinal axis orthogonally to the respective face (Sa, 5b, 5c) of the housing ( 3) from which it emerges. The holding element (1) advantageously comprises locking means (MB) intended to limit the longitudinal displacement of the different clamping wedges (4a, 4b, 4c) along their respective axes. Thus, each of the wedges (4a, 4b, 4c) can only move between a so-called projecting position where the head (6) of the wedge (4) emerges from the face (5, Sa, Sb, 5c) of the housing (3) with a maximum distance (d) as illustrated in FIG. 8a and a so-called withdrawal position in which the head (6) of the wedge (4) is located substantially at the level of the face (5). Note that, in the retracted position, said head (6) may emerge slightly from the face (5) or be flush with it so as to avoid any projection of dirt in the orifice (7) of the housing, as shown Figure 8b. It goes without saying that the withdrawal position could be different, the head of the wedge withdrawing into the orifice without however leaving the protective field of the invention.

 According to the preferred embodiment of the holding element, the locking means (MB) advantageously consist of a hollow longitudinal profile (8) of finite length, disposed laterally on the clamping wedge (4) and which is intended to slide longitudinally around a blocking member such as a rod or a blocking pin (9) secured to the body (3). The locking pin (9) thus bears alternately against the two longitudinal end surfaces (8a, 8b) of the hollow profile (8) during the movement of the clamping wedge (4) thus delimiting the two extreme positions of said movable clamping wedge illustrated respectively in FIGS. 8a and 8b.

 According to the preferred embodiment of the holding element (1), this comprises three movable clamping wedges (4a, 4b, 4c). Said shims are advantageously arranged in the housing (3) of the element (1) so that their respective longitudinal axes are coplanar. Thus, the three wedges are arranged in a longitudinal plane (P) advantageously located in the upper part of the body (3), as shown in Figures 3, 4, 5a and 5b. According to this embodiment, the mobile wedges (4a, 4b, 4c) are of cylindrical shape with identical diameter (D1) and move in internal bores (10) of the body (3) opening onto the respective faces (Sa, Sb , Sc) orthogonally thereto. It goes without saying that the number of clamping shims could be different, without however departing from the claimed protective field of the invention. Similarly, the arrangement of the shims could be three-dimensional, for example, and the profile of said shims of a different geometric shape.

 Note that the hollow profile (8) of the cylindrical shims (4, 4a, 4b, 4c) can be produced by a longitudinal groove, for example. It can, as in the preferred embodiment of the device, be constituted by a lateral flat, as shown in FIG. 6.

 According to the preferred embodiment and its variant embodiments, the locking members (9) are disposed inside the body (3) in a fixed manner. Thus, they can for example be constituted by headless screws with studs (50), as shown in FIG. 5b. Said screws are arranged in complementary threaded bores (11), advantageously situated in the longitudinal plane (P) of the clamping wedges (4a, 4b, 4c) and are arranged orthogonally to the respective internal bores (10) in which said wedges slide. Note that during the mounting of the retaining elements, the stud screws can be of dimension adjusted in length, so that their stud itself (9a) comes out in the internal bore (10) to operate the blocking of the surfaces d end (8a, 8b) of the hollow profile (8) of the wedge (4) and that their rear end remains on the surface (5) of the housing on which the complementary bore (11) opens, so as to prevent any intrusion of dirt, projection or other particles inside the housing (3).

 According to the variant illustrated in FIG. 5a, the locking pins (9) consist of portions of rods adjusted to their complementary bore (11), said rods advantageously being arranged in their respective bores by forced fitting, for example.

 According to the invention, the mobile clamping wedges (4a, 4b, 4c) are interconnected by connecting and actuating means (MLA) intended to allow the transmission of a clamping force exerted on one of the shims (4a) to the other shims (4b, 4c) of the holding element (1) and vice versa as well as to cause the displacement of the shims (4b, 4c) to bring them into abutment on a part (2) or a wedge of another element in order to transmit the clamping force to them.

 According to the preferred embodiment of the holding element, one of the shims (4a) is of perfectly cylindrical shape, while the other two clamping shims (4b, 4c) illustrated in FIG. 6 have a bevelled cylindrical shape, so that present an inclined bearing surface (12) intended to cooperate with an intermediate transmission part (13) illustrated in FIG. 7 in a cam-push type connection, said part constituting the connection and actuation means (MLA) of the element holding (1). The mobile clamping wedges (4b, 4c) having a beveled end are arranged along the same longitudinal axis (XX ') said to slide in the plane (P), while the other wedge (4a) is arranged orthogonally along an axis median (YY '), the intermediate transmission part (13) being arranged at the intersection of the three shims (4a, 4b, 4c) along the sliding axis (XX'). The intermediate transmission part (13) is in a manner known per se in the form of a beveled cylinder at its two ends so as to present two bearing surfaces (14a, 14b) complementary to those of the beveled shims (4b, 4c). It has a diameter (D2) smaller than the diameter (D1) so that it can move along the axis (YY ') under the action of the cylindrical shim (4a) so as to act on the bevelled shims (4b, 4c ) or under the action of one or two bevelled shims to act on the cylindrical shim.

 According to the preferred embodiment, the holding element (1) and more particularly its housing (3) comprises in its lower part positioning and fixing means. Said means may, for example, be constituted by threaded longitudinal or transverse holes (15a, 15b, 1Sc, 15d) or by a lower profile (16) in the form of a dovetail allowing appropriate guidance or by any other equivalent means. .

 Of course, the invention is not limited to the embodiments described and shown by way of examples, but it also includes all the technical equivalents and their combinations.

Claims (7)

 1. Workpiece holding element (1) (2) in a clamping device (100) intended to position workpieces, for example, of the type comprising a housing body (3) equipped with a set of movable shims clamping (4, 4a, 4b, 4c) emerging from different faces (5a, Sb, Sc) of the housing (3), said clamping wedges (4, 4a, 4b, 4c) being linked together by connecting and actuating means (MLA) intended to transmit the forces between the wedges and to cause them to move .  2. holding element (1) of parts (2) according to claim 1, characterized in that it comprises locking means (MB) intended to limit the displacement of the movable wedges (4, 4a, 4b, 4c).  3. holding element (1) of parts (2) according to claim 2, characterized in that the locking means limit the respective movement of each of the movable clamping wedges (4, 4a, 4b, 4c) between two extreme positions , a projecting position where the head (6, 6a, 6b, 6c) of the shim emerges from the face (5, Sa, Sb, Sc) of the housing (3) and a withdrawal position where the head of the movable shim is set back from the face at its level or very slightly protruding.  4. holding element (1) of parts (2) according to claim 2 or 3, characterized in that the locking means (MB) consist of a hollow profile (8) longitudinal disposed laterally on the wedge (4) , intended to slide between two extreme positions around a locking pin (9) secured to the body (3).  5. holding element (1) of parts (2) according to claim 4, characterized in that the movable shims (4, 4a, 4b, 4c) are of cylindrical shape and in that the hollow profile (8) is produced by a lateral flat.  6. holding element (1) of parts (2) according to claim 4 or 5, characterized in that the blocking pins (9) are constituted by portions of rods fitted into forced complementary internal bores (11) orthogonal to the longitudinal axis of the wedge (4, 4a, 4b, 4c) whose movement they limit.  7. holding element (1) according to any one of the preceding claims, characterized in that it comprises three movable clamping wedges (4a, 4b, 4c) of cylindrical shape of diameter (dol), arranged in a longitudinal plane (P) of the housing (3), two wedges (4b, 4c) whose end located in the housing is bevelled being arranged along a longitudinal axis (XX '), while the third perfectly cylindrical wedge is arranged along a transverse axis median (YY ') orthogonal to the axis (XX').   & Workpiece holding element (1) (2) according to claim 7, characterized in that the connection and actuation means (MLA) consist of an intermediate transmission part (13) of cylindrical shape, arranged between the mobile clamping wedges (4a, 4b, 4c) along the longitudinal axis (XX '), the ends of which have a beveled shape complementary to that of the two beveled wedges (4b, 4c) and whose diameter (D2) is less than diameter (D1) of the clamping shims (4a, 4b, 4c).  9. Clamping device (100) of parts (2) comprising a set of holding elements (1, la, lb, lc) according to any one of the preceding claims, said elements being kinematically connected.