FR2497140A1 - DEVICE FOR LOCKING PLACES OF METAL MOLDS - Google Patents

Abstract

A CLAMP DEVICE SPECIFIC TO LOCKING THE BASE OF A MOLD ON A PRESS PLATE INCLUDES A FORK-SHAPED LOCKING ARM 8 OPENING ON THE LEFT OF THE FIGURE AND WHOSE FREE ENDS OF THE BRANCHES ARE SLOTTED ON AT LEAST ONE OF THEIR HORIZONTAL FACES OF A LOW 12 IN THE FORM OF A STAIR STEP. AT THE OTHER END OF 8 IS A SPACER 3 WITH RECTANGULAR PROFILE (SIDES P AND Q), RETAINED IN PLACE BY SPRINGS 7 AND LINK PLATES 7 WITH EXTENDED OPENING. THE CLAMPING SCREW 5 CROSSES 8 AND ACTS THROUGH THE PLATE 4. THE CLAMPING HEIGHT X CAN THUS BE ADJUSTED TO FIVE DIFFERENT VALUES BY TURNING SHIM 3, DELETING IT ON THE REAR, OR RETURNING 8 ON HIMSELF SO THAT IT ACTS BY 12 THE SURFACE OF THE STEP. BY PROVIDING A VACUUM OR OPERATION ON THE OTHER SIDE OF THE BRANCHES, EIGHT SETTING VALUES ARE ARRIVED.

Description

your present invention relates to a device for blocking in place of

  metal molds which facilitate assembly and removal

of these.

  During the molding of plastics by injection, compression or transfer, molds are fixed to the press used which conform the product to be produced. Special devices are thus used to

  block the four points of the mold fixing plate in question -

  know the upper and lower ends of its right and left sides. Fig. 15 of the accompanying drawing shows in plan a conventional example of such a locking device. This includes a clamping bar A, a spacer B and a screw C. The fact that two metal half-molds are fixed vis-à-vis on a fixed plate and a movable plate (referenced D) of the molding press, towards the upper and lower ends of both sides, it

  eight devices must be used to lock the mold in position.

  The fixing plates F are applied against the plates D of the molding press by the clamping bars A. Fig. 16 shows a perspective view of one of these; this consists of an elongated block comprising a slot G. The screw C passes through this slot G and is screwed into the plate D. The spacer B is interposed between the clamping bar A and the tray

  D to maintain the first parallel to the latter.

  However, these metal mold fixing devices are inconvenient because they require a long operating time for the

install or remove them.

  First of all, for safety reasons, the screws C must be completely removed to detach the clamping bars A from the plates D. In this case, the screw in question must be turned over the entire length of engagement of the threads. But this rotation of the

  screw following a large number of turns is tedious work.

  Secondly, depending on the different thicknesses of the fixing plates F, spacers B must be used, the thickness of which agrees with that of the plate. Therefore we must

  always be able to have B holds of multiple dimensions.

  Thirdly, if the screw C turns out to be hard to turn, the operator must maneuver it using a key, holding it with one hand while with the other holding the bar. tightening A and the spacer B. In fact if these two members were left free, the spacer B could fall on the operator's feet during

loosening of the screw.

  Consequently, conventional locking devices require a great deal of time to mount them on the plate of the molding press or remove them therefrom. In addition the operation is not carried out

always safe.

  To obviate the foregoing difficulties, another device has been devised in which the locking bar and the spacer are a whole. Fig. 17 is in the street in perspective of this device of the prior art. Here the bar M has at its spacing a adjusting screw I. A separate plate J, fits on the plate of the

  press with screw K, tighten bar M on fixing plate.

  If the thickness of the pre.itâe plate varies, this device makes it possible to block nanmoin3 any slack! Regulating the length dapasa-ate of the adjusting screw I. It therefore does not require that we establish different

  types of spacers. This is an important advantage.

  However, we encountered another difficulty, precisely because of this possibility of progressive adjustment. In fact, the thickness of the mounting plate of a metal mold is standardized in many countries. For example, in some of them, a small number of such plates are made,

  the thickness varies in steps of 5mm.

  When using the device shown in fig. 17, the operator must visually evaluate the protruding length of the adjusting screw I. Because this length varies constantly and also because the evaluation at sight is not precise, it loses a lot of time and trouble to fix the bar H at a position parallel to the surface of the

press shelf.

  Another drawback appears. The upper end - 30 of the adjustment screw i interferes with the rotation of the cl1 engaged on the screw K>

  more particularly in the case of thin fixing plates.

  The invention aims to solve difficulties and to make it possible to establish convenient devices for blocking in place of metal molds, and which can be assembled or disassembled easily and safely in one

very short time.

  The appended drawing, given by way of example, will allow a better understanding of the invention, the characteristics which it has and the advantages which it is likely to provide: FIG. 1 is a plan view of an embodiment of a

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  device according to the invention for fixing a metal mold

on a press.

  Fig. 2 is an elevational view thereof.

  Fig. 3 is a section along III-III (fig. 2).

  Fig. 4 is a perspective view illustrating how one fixes

  the device on a metal mold.

  Fig. 5 schematically shows the position at which the

  device blocks a fixing plate with the maximum thickness.

  Fig. 6 is a diagram similar to that of FIG. 5, but corresponding to a plate whose thickness is located at the next lower level. Fig. 7 corresponds in turn to the level which follows that of

fig. 6.

  Fig. 8 illustrates the case of the fourth level of thickness of the

fixing plate.

  Fig. 9 finally corresponds to the fifth level.

  Fig. 10 schematically shows in elevation another shape

of the invention.

  Fig. 11 is a plan view of a fixing device for

  metallic molds established according to a third embodiment.

  Fig. 12 is an elevational view thereof.

  Fig. 13 is a section along XIII-XIII (fig. 12).

  Fig. 14 shows in perspective in an isolated state the device

according to fig. 12 and 13.

  Fig. 15 is a plan view which, as indicated above,

  shows the attachment of a mold by means of a conventional device.

  Fig. 16 shows in perspective the blocking bar in

such a device.

  Fig. 17, also already mentioned above, illustrates a

  other prior art fastening device.

  A device 1 for fixing metal molds comprises a clamping part 2 suitable for blocking the plate for fixing the latter on the plate of a molding press, a spacer 3 intended to keep the part 2 parallel to a plate. , a clamping plate 4 suitable for urging the part 2 on the mold fixing plate, and

  a screw 5 which fixes said plate 4 on the aforementioned plate.

  Part 2 and spacer 3 are connected to plates

  link 6 comprising an elongated hole and a spring 7.

  The clamping piece 2 comprises two front locking arms 8

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  and an assembly block 9 welded to the rear ends 10 of the latter in order to produce with them a single member. So we find a front entrance

  11 which opens between the arms 8 for the passage of the fixing screw 5.

  In addition towards the ends of these arms, parts 12 have been managed in the form of a stair step. As shown in fig. 4 3the clamping piece 2 seizes the clamping plate 4 or is easily removed The connecting plates 6 are suspended loosely on either side of the piece 2 by means of a rivet 13 which crosses it and they are weakly stressed against the lateral dimensions of the

  wedge 3 by screws 14 and 15 fixed to the aforementioned sides.

  The springs 7, which are stretched between the rivet 13 and the screws 14, urge the spacer 3 towards the clamping part 2 by elastic reaction effect. They facilitate the assembly or disassembly of the part 2 because the wedge 3 is always facing f: ace in

  contact with it under the action of springs.

  The lateral face of the spacer 3 is not square, but rectangular. In other words, the lengths of its two ribs are not equal. We have reference P the longest side of the rectangle and Q

the smallest.

  In fig. 2 the large side P is in contact with the clamping piece 2.

  If the operator rotates the wedge 3 by 90 from the position shown, it is the small side Q which is applied against the workpiece.

  We indicated in R the drop corresponding to step 12.

  When the operator turns over the clamping piece 2 to bring it to the position opposite that of FIG. 2, it can block on the plate another fixing plate having a thickness which exceeds that of the first of the quantity R. Because the fixing plate F is blocked by the anterior ends of the arms 8, the height X of their lower faces above the base plane in which the inner face of the shim 3 is located, must be equal to the thickness of the fixing plate F so that the part 2 is kept parallel to the plate of the press

molding.

  Thanks to the loose connection produced by the plates 6 and the springs 7 between the clamping piece 2 and the spacer 3, the above-mentioned piece can be overturned and the spacer itself turned. Under these conditions the height X of the anterior ends of the part 2, such

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  as defined above, can take one of the following five values (1) X = R + P (fig. 5) (2) X = R + Q (fig. 6) (3) X = P (fig. 7 ) (4) X = Q (fig. 8) (5) X = R (fig. 9) In fig. 5 a fixing plate with the maximum thickness is blocked by the recessed face of the stair tread 12 of the arms 8

  which is in contact with the shortest side of the spacer.

  The height X is then equal to the sum of that of the long side P of the spacer and the difference in height R corresponding to the step

staircase 12.

  In the second state shown in fig. 6, the largest side of the spacer is in contact with the locking arms. The height X is then equal to the total of the short side Q and the difference in height R

a walk.

  In the third state corresponding to fig. 7, the clamping piece has been reversed and its entirely flat face 19 comes to bear on a fixing plate whose thickness is equal to the length of the large

side P of the spacer.

  In fig. 8 the wedge has been rotated 900 from the position shown in fig. 7. It is thus possible to block on the press plate a fixing plate with a thickness equal to the length of the small side Q

of this wedge.

  Finally in the fifth state shown in fig. 9, the spacer has been moved against the rear end of the clamping piece. The

  height X is equal to the difference in height R of the staircase 12.

  Thus the device is valid for five types of metal molds

  with fixing plates of different thicknesses.

  For example if the values P, Q and R are assumed to be equal respectively-

  25 mm, 20 mm, and 10 mm, the device can be used with the whole range of fixing plates with thicknesses of 35 mm, 30

mm, 25 mm, 20 mm or 10 mm.

  Fig. 10 schematically shows a metal mold blocking device according to a second embodiment of the invention. Another step is provided here in elevation 12 ′ on the face opposite to step 12. The device thus produced can block fixing plates by means of three different surfaces, namely the upper face 19 and that of the steps. 12 and 12 '. We have reference S

  the drop corresponding to the new 12 'step.

  Under these conditions, the blocking height X of the mold fixing plate can be freely chosen from the following eight values:

(1) X = S + P

(2) X = R + P

(3) X = S + Q

(4) X = R + Q

(5) X = p o10 (6) X = Q Q (7) X = s

(8) X R

  In practice the clamping plates 4 soet mounted on the plates of the molding 9resee by means of the fixing screws 5, After having slightly loosened these and the operator puts in place remove the clamping piece 2 with the wedge spacing 3. This mounting or mounting operator is carried out horizontally. It is therefore better to conform the tightening plate 4 asymmetrically. In the example, the side edges 17 and 18 of this plate have different thicknesses. Because lers poiS of these rdbords 17 and 18 are not égaLxC, the wafer 4 s -'e nte in a stable manner following a vertical sow; the effect of gravity. This erresprnd for this wafer in a normal state that has been resumed; at the end, 4. It is then very convenient for the operator to mount the clamping piece under said

  plate 4 by making it gl: emit in the horizontal direction.

  In the example described below, the clamping piece 2 is established I

  from three metallic elements which are welded into a single whole run.

  As such pisce3 are easily obtained by cutting a bar

  rectangular, the cost price is particularly low.

  But of course this clamping piece could be made from the start in the form of a ur body, without any welding operation.

  Fig. 11 to 14 show a third embodiment of the invention.

  Next it the clamping piece 2 is established in the form of a single metal body whose front is cut in the shape of a fork. The other characteristics are substantially common

  with those corresponding to the first previous embodiment.

  We find the interior entrance 11 formed between the arms of the fork for the passage of the fixing screw 5. The connection plates 6 and

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  the springs 7 loosely connect the part 2 to a space block

ment 3.

  In the device of fig. 11 to 14, which have been referenced 20, screws 21, 22, 23 and 24 are used to suspend the plates 6. But these screws could of course be replaced by rivets. In addition it is possible to dispense with the springs 7 because the necessary condition concerning the connection between the clamping piece 2 and the spacer 3 is that the latter cannot be separated from the first, but can rotate around that -this, as well

besides that around itself.

  The invention provides the following results (1) The operator does not need to completely remove the fixing screw 5; on the contrary, it can leave it in place on the plate of the molding press. He just has to block or release the

  clamping piece by turning the screw only a few turns.

  Because this screw rotation operation is greatly reduced while it is generally very long, it is possible for the operator to assemble or disassemble a metal mold on the press

  corresponding in a relatively short time.

  The spacer 3, which is connected to the clamping piece 2, does not fall when the fixing screw 5 is loosened. This fact ensures the

operational security.

  Thus the main result of the invention lies in the ease

  and the safety it provides to the operator.

  (2) In many cases the thickness of the mold fixing plates is normalized to certain determined values, different from each other. This thickness can for example be 20 mm, 25 mm, 30 mm, etc.

  Due to the fact that the device according to the invention combines the clamping part with parts lowered in stair treads, as well as with a rectangular lateral face for the spacer, it adapts as desired to these different thickness values of the fixing plate. In addition, as the variation in the clamping height is not gradual, but in successive stages, the invention avoids the operator committing inaccuracies by evaluating this height.

  (3) Finally, if the clamping plate 4 is asymmetrical, it is stable at rest along a vertical line under the effect of gravity. This facilitates the operation of mounting the clamping piece 2 since the operator does not have to ensure the prior orientation of the

plate 4.

  The invention therefore corresponds well to technical progress.

  It should also be understood that the foregoing description has not

  been given only as an example and in no way limits the field of the invention from which one would not depart by replacing the

  execution details described by all other equivalents.

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Claims (8)

R E V E N D I C A T I 0 N S   1. Device for locking in place a metal mold, characterized in that it comprises in combination the following elements, at least some of which are known either in the isolated state, or in combinations different from the one below.   - a clamping piece (2) comprising two arms (8) between which an opening (11) is formed, while their ends are cut out from a stair step (12, 12 ') set back on at least one their two faces; - a spacer (3) with rectangular side faces with a long side (P) and a short side (Q); - a connecting plate (6) connecting the spacer (3) to the rear end of the clamping piece (2) loosely thereby allowing the spacer (3) to rotate; - a clamping plate (4) suitable for acting on the clamping piece (2); - and a screw (5) to fix the clamping plate (4) on the plate of a molding press.   2. Device according to claim 1, characterized in that the clamping plate (4) is asymmetrical with respect to the screw fixing (5).   3. Device according to claim 2, characterized in that the clamping plate (4) has two flanges (17, 18) of thicknesses different.-   4. Device according to claim 1, characterized in that it comprises springs (7) stretched between the spacer (3) and the rear ends of the clamping part (2) to elastically stress the first against the second.   5. Device according to claim 1, characterized in that on one and the other face of the arms (8) of the clamping piece (2) is hollowed out a staircase depression (12, 12 '), these two steps   corresponding to different elevations (R, S).   6. Device according to claim 1, characterized in that the clamping part (2) is constituted by two parallel arms (8) and by   an assembly block (9) welded to the rear ends thereof.   7. Device according to claim 4, characterized in that it comprises a rivet (13) which passes through the rear end of the clamping part (2) and screws (14, 15) fixed on the lateral sides of the wedge spacer (3) to hold the connecting plates (6) and the   springs (7) while allowing the shim (3) to rotate.   8. Device according to claim 4, characterized in that it comprises screws (21; 22) fixed to the rear of the lateral faces of the clamping part (2), as well as other screws (23, 24) fixed to the lateral faces of the spacer (3) to ensure the retention of the connection plates (6) and the springs (7) while allowing the wedge (3).