EP1281480A1 - Clamping device - Google Patents

Abstract

The gripping yoke (1) consists of an upper jaw (4) that can be deployed and retracted relative to a lower thrust member (3) by means of a power cylinder. In the retracted position the jaw and thrust member lie flush with one another, while in the deployed position the jaw rotates about its axis by means of a guide rod in the power cylinder so that a workpiece can be gripped between the jaw and thrust member.

Description

The present invention relates to a clamp. It relates to more particularly a clamp intended for positioning and the maintenance of parts during their machining by machining centers specific working by chip removal.

We know many types of clamps for blocking of parts for their machining. We thus find the lever flanges swivel which encloses the part between the lever arm and a flange bearing surface. However, this type of flange is not suitable for this type of work due, in particular, to the absence of retraction of support.

In the wood sector, several solutions have been developed and in particular vacuum systems such as vacuum tables or vacuum tables. However, for certain machining of parts, the suction surface is too small compared to the cutting force and these vacuum systems are therefore not suitable for this type of work wooden parts. Some manufacturers have developed vices pneumatic tires mounted on suction cup.

However, these vices also have drawbacks linked to their size, the absence of retractable support and their number necessary to maintain the part. So, to be able to practice certain machining operations, the user must move said vices to release the tool path, this sometimes requires the machine to be stopped temporarily and thus makes machining longer.

The object of the present invention is to remedy the disadvantages mentioned above using means, simple, reliable, easy to put implemented and inexpensive. It offers an easy to use clamp and which can be retracted to leave sufficient space for the passage of cutting tools during machining either at the flange, either at the level of support.

According to its main characteristic, the clamp the invention is of the type comprising an upper jaw with a surface of stop and a lower jaw with a bearing surface, said jaws being movable to move relative to each other along an axis of displacement under the action of biasing means, and is characterized in which it includes a retracting device which allows one of the bearing or abutment surfaces to retract to pass from a position of clamping where it at least partially covers the other bearing surface or stop in the direction of movement of the jaws in a free position where it no longer covers it and vice versa.

According to another characteristic of the clamping flange the invention, it is characterized in that the retracting device is implemented by the displacement of the jaws under the action of the means of solicitation.

According to an additional characteristic of the clamping flange the invention, it is characterized in that the retracting device is a swivel type device which allows the flange to be swiveled greater than the other around the axis of movement of the jaws.

According to the preferred embodiment of the clamp, the biasing means include a secondary cylinder which moves the upper flange with respect to the lower support along the axis of displacement.

According to another characteristic of the clamping flange the invention, it is characterized in that the displacement of the flange between a low point and a high point and in that the pivoting of the upper flange, thanks to the retracting device, takes place when moving it in the ascending phase nearby from the high point, and when it goes from a low rest position corresponding to the low point at a high clamping position or Conversely.

According to the preferred embodiment of the clamping flange the invention, the retraction device comprises a guide rod and fixed pivoting having a propeller intended to cooperate with a dog clutch to rotate it half a turn when it travels the rod and its propeller from bottom to top, said dog comprising notches which allow it to be secured in rotation with a drive plate integral with a cylinder rod which partly forms the upper flange, to obtain pivoting of the flange surface upper when the retraction device is used.

According to this embodiment, the jack rod, which carries a flange to its upper end to form the upper flange, has a internal bore, the upper part of which is intended to allow the passage of the guide and pivot rod, the lower part of which constitutes a housing for the training dog whose dimensions allow the dog to be positioned either in the engaged low position where its notches cooperate with the notches of the drive plate attached to the actuator rod to rotate it during the climb, or high position where the notches are disengaged to let the dog pivot freely as the cylinder rod descends along the rod guidance and pivoting.

According to another characteristic of the clamping flange the invention, it is characterized in that the biasing means include a main cylinder that allows the movement of the support lower, while said lower support forms the cylinder body of a secondary cylinder whose cylinder rod partly forms the upper flange and in that the retracting device is implemented so automatic by moving the upper flange under the action of the secondary cylinder.

According to an additional characteristic of the clamping flange the invention, it is characterized in that the shape of the support and of the upper flange jaw is complementary to constitute together a circular profile centered on the axis of movement of the jaws.

According to the preferred embodiment of the clamping flange the invention, the shape of the surface of the lower support is a portion of circle smaller than that of the abutment surface of the upper jaw.

Other characteristics and advantages of the invention will emerge of the description which will follow with regard to the appended drawings which are not given only by way of nonlimiting examples.

La figure 1 représente en perspective la bride de serrage au repos.

La figure 2 illustre en perspective la bride de serrage en position intermédiaire avant le pivotement du mors supérieur.

La figure 3 illustre en perspective la bride de serrage lors du pivotement du-mors supérieur.

La figure 4 représente en perspective la bride de serrage en position haute après le pivotement du mors supérieur.

La figure 5 représente en perspective la bride de serrage en position de serrage.

La figure 6 illustre en coupe transversale la bride de serrage et son mécanisme.

La figure 7 illustre en perspective la coopération des moyens d'entraínement avec la tige de guidage et de pivotement.

Les figures 8a à 8d illustrent schématiquement la bride de serrage lors du passage de la position de repos vers une position de serrage.

Les figures 9a à 9d représentent schématiquement la bride de serrage lors du passage de la position de serrage vers la position de repos.

Figures 1 to 9d illustrate the preferred embodiment of the clamp of the invention and its components.

Figure 1 shows in perspective the clamp at rest.

Figure 2 illustrates in perspective the clamp in the intermediate position before the pivoting of the upper jaw.

Figure 3 illustrates in perspective the clamp when pivoting the upper jaw.

Figure 4 shows in perspective the clamp in the high position after the pivoting of the upper jaw.

Figure 5 shows in perspective the clamp in the clamping position.

Figure 6 illustrates in cross section the clamp and its mechanism.

Figure 7 illustrates in perspective the cooperation of the drive means with the guide rod and pivot.

Figures 8a to 8d schematically illustrate the clamping flange when passing from the rest position to a clamping position.

Figures 9a to 9d schematically show the clamp when passing from the clamping position to the rest position.

The present invention relates to a clamp carrying the general reference (1). It is more particularly intended for positioning and clamping of parts (2) for their machining by specific machining centers; however, it could be used for other similar applications with minor adaptations without however, depart from the claimed protective field of the invention. She has a lower support (3) provided with a lower support surface (3a) and an upper jaw (4) with an upper clamping surface (4), said jaw allowing to grip a piece (2), as shown in particular Figure 5. In its clamping position (A), the flange (1) has its upper clamping surface (4a) perpendicular to its surface lower support (3a), while biasing means allow to solicit them towards each other.

According to the invention, the lower support (3) and the upper jaw (4) are movable relative to each other to move along an axis (ZZ ') called axis of displacement of the jaws under the action of the means of solicitation. It may be noted that, according to the preferred embodiment of the clamp, this has a rounded shape and the axis of displacement (ZZ ') is its axis of revolution, the flange being preferably intended to be used upright with the axis (ZZ ') disposed at the vertical. One could however conceive variants of execution where the clamping of the jaws would no longer be carried out on the height, but so lateral without departing from the protective field of the invention.

According to the invention, the clamp (1) comprises a device retraction which allows to move one of the bearing surfaces or clamping (3a, 4a) of the lower support (3) and the upper jaw (4) to that it is no longer plumb with the other surface. Thus retracted, when the jaws move between them along the axis (ZZ '), their surfaces support and clamping (3a, 4a) cannot grip parts and the jaws can thus come to the rest position (B), as illustrated in FIG. 1.

According to the preferred embodiment, the retracting device is a swivel-type device which allows the surface of the upper clamping (4a) around the axis of movement (ZZ ') of the support lower (3) and upper jaw (4) so that it no longer covers according to the direction (ZZ ') the lower support surface (3a) of the lower support (3).

According to the invention, the retraction device is actuated by the biasing means which manage the movement of the lower support (3) and of the upper jaw (4) along the axis (ZZ '). It is thus implemented from automatically when moving the lower support (3) and the upper jaw (4) and is therefore not managed independently of these. The biasing means are constituted by a jack (5) called jack secondary, advantageously of pneumatic type, which acts on the jaw upper (4) to move it relative to the lower support (3) which forms the body of this secondary cylinder. Said displacement of the upper jaw (4) advantageously takes place between a high point (C), illustrated in FIGS. 8c and 9c, and a low point (B), illustrated in FIGS. 8a and 9d, corresponding to the position rest. Note that the clamping position (A) illustrated in Figures 8d and 9a is located between the high point (C) and the low point (B) in the travel of the jaw (4) to an intermediate position defined as a function of the part (2) to be clamped.

According to the invention, the retraction device is actuated by the displacement of the upper jaw (4) when it is near the high point (C) in an ascending phase, it makes it possible to rotate the clamping surface (4a) of the jaw (4) so that it no longer covers, even partially, the support surface (3a) of the lower support (3) according to the direction of movement (ZZ ') of the lower support (3) and the jaw upper (4).

Note that, according to the preferred embodiment of the invention, the retracting device is a mechanical type device which is not actuated or implemented only by the movement of the jaw (4) under the action of the jack (5) which moves it along the axis (ZZ '). It consists of a rod guide and pivot (6) which has at its upper end a propeller (7) intended to cooperate with a drive dog (8a) and its drive plate (8b) for rotating a cylinder rod (9) secured to said plate. The cylinder rod (9) carries at its end upper jaw (10) which has on its lower face the surface upper clamping (4a), it forms with said jaw the jaw upper (4).

According to the preferred embodiment of the clamp, the rod guide and pivot (6) has a rectangular section intended to guide the dog (8a) which itself has an internal profile similar. The propeller (7) forms a half-turn (180 °), as shown in the Figure 7, and causes the U-turn dog (8a) to turn around when it runs through it. The dog (8a) is driven in longitudinal displacement towards the top (HA) by the drive plate (8b) which is integral with the rod cylinder (9), under the action of the secondary cylinder (5). Training notches (11a, 11b) make it possible to secure in rotation the plate (8b) and the dog clutch (8a) during this climb so that the U-turn turns the same movement of the plate (8b) and therefore of the rod (9) around the rod guide and pivot (6) which is arranged along the axis of displacement of the jaws (ZZ '). When the dog, the plate and the bit upper have reached the high point (C) illustrated in Figures 8c and 9c, the cylinder secondary causes them to descend along the guide rod and pivoting (6) while the dog clutch (8a) moves away from the plate (8b) so as to disengage their notches (11a, 11b), leaving the plate (8b) and the rod (9) descend along the guide and pivot rod (6) under the action of the jack (5) without pivoting, while the dog clutch (8a) undergoes freely the U-turn generated by the propeller (7) of the guide rod and pivoting (6) without causing the plate and the jaw to pivot, as shown in Figures 8c, 8d and 9c, 9d. The dog (8a) having undergone its U-turn, it returns to position itself on the plate (8b) with its notches position engaged to be able to be driven by said plate in translation along the rod (6) while transmitting its movement of pivot during the next ascending phase.

It can be noted that the cylinder rod (9) has an internal bore the upper part (12) of which favors the passage of the guide rod and pivot (6) and the lower part (13) of which forms a housing for the drive dog (8a). This accommodation is of sufficient size to allow the dog to take a low position where it is blocked in rotation by the notches (11b) of the plate (8b) and a high position where its notches (11a) are disengaged from the notches of the plate (8b) allowing it thus pivot freely in its housing during the descent.

According to the embodiment illustrated in FIGS. 1 to 9d, the flange of clamping (1) comprises a main cylinder (14) intended to allow the movement of the lower support (3) along the axis of movement (ZZ '). Thus, the support (3) which forms the cylinder body of the secondary cylinder (5) which manages the movement of the upper jaw (4) is also mobile according to the direction (ZZ ') inside the body (16) of the main cylinder (14). support lower (3) thus forms the piston of the main cylinder and can be retracted down to let the tool pass when it is no longer in use. note that this lower support (3) carries the guide and pivot rod (6) which allows the upper jaw (4) to pivot.

According to the preferred embodiment of the clamp (1) of the invention, the main and secondary cylinders (5,14) are type cylinders pneumatic whose supply is managed by a control unit based on information given by the machining center that machines the piece or by sensors arranged on the flange. Of course, he could be considered other types of motorization, without leaving the protective field of the invention.

Furthermore, it can be noted that the shape of the jaws (10, 15) of the upper jaw (4) and the lower support (3) is complementary in order to form a circular profile centered on the axis of movement of the jaws (ZZ '), as shown in Figure 1, when in the rest position. So the lower jaw has a bearing surface (3a) whose shape is a portion of circle smaller than the clamping surface (4a) which corresponds to the other portion of the complementary circle.

Of course, the invention is not limited to the modes of realization described and represented as examples, but it includes also all technical equivalents and their combinations.

Claims (9)

Clamp (1) comprising an upper jaw (4) with a clamping surface (4a) and a lower support (3) with a bearing surface (3a), said jaws being movable to move relative to each other to the other along a displacement axis (ZZ ') under the action of biasing means, while a retracting device which allows one of the bearing or clamping surfaces (3a , 4a) to retract to pass from a clamping position (A) where it at least partially covers the other bearing or abutment surface (3a) in the direction of movement of the jaws (ZZ ') to a free position where it no longer covers it and vice versa, characterized in that the retracting device is implemented by moving the upper jaw (4) and the lower support (3), under the action of the means of solicitation. Clamp (1) according to claim 1, characterized in that the retracting device is a pivoting type device which makes it possible to pivot one of the bearing or clamping surfaces (3a, 4a) relative to the other around the axis of movement of the jaws (ZZ '). Clamp (1) according to any one of the preceding claims, characterized in that the biasing means comprise a secondary cylinder (5) which displaces the upper jaw (4) relative to the lower support (3) along of the axis of movement (ZZ '). Clamp (1) according to Claims 2 and 3, characterized in that the displacement of the upper jaw (4) takes place between a low point (B) and a high point (C) and in that the pivoting of the jaw upper (4) thanks to the retracting device (DE) is carried out during the displacement of the latter in ascending phase near the high point (C), and this, that it passes from a rest position corresponding to the low point (B) at a clamping position (A) or vice versa. Clamp (1) according to any one of the preceding claims, characterized in that the retraction device comprises a fixed guide and pivot rod (6) having a propeller (7) intended to cooperate with a dog clutch. drive (8a) to rotate it by half a turn when it traverses the rod and its propeller, said dog comprising drive notches (11a, 11b) which allow it to be secured in rotation with a drive plate (8b) integral with a jack rod (9) which partially forms the upper jaw (4), to obtain the pivoting of the clamping surface (4a) of the upper jaw (4) when the retraction device is put in action. Clamp (1) according to claims 4 and 5, characterized in that the cylinder rod (9), which carries a jaw (10) at its upper end to form the upper jaw (4), has an internal bore ( 12,13) whose upper part is intended to allow the passage of the guide and pivot rod (6) and whose lower part (13) constitutes a housing for the drive dog (8a) whose dimensions allow the dog to be positioned in the engaged low position where its notches (11a) cooperate with the notches (11b) of the drive plate (8b) fixed to the jack rod (9) to cause it to pivot and in the high position where the notches (11a, 11b) are disengaged to let the dog pivot freely while the cylinder rod (9) descends along the guide and pivot rod (6). Clamp (1) according to any one of the preceding claims, characterized in that the biasing means comprise a main cylinder (14) which allows the displacement of the lower support (3), while said lower support (3 ) forms the cylinder body of a secondary cylinder (5) whose cylinder rod (9) partially forms the upper jaw (4) and in that the retraction device is implemented automatically by the displacement of the upper jaw (4) under the action of the secondary cylinder (5). Clamp (1) according to any one of the preceding claims, characterized in that the shape of the jaws (10, 15) of the lower support (3) and of the upper jaw (4) is complementary in order to form a profile together circular centered on the axis of displacement of the jaws (ZZ '). Clamp (1) according to claim 8, characterized in that the shape of the support surface (3a) of the lower support (3) is a smaller portion of a circle than that of the clamping surface (4a ) of the upper jaw (4).

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