Plastic injection mould slide retainer

Abstract: Specially conceived for slides (1) which run along a track (2), having a housing (4) which is slanted in relation to the said track, a housing in which a guide (3) operates, also slanted, in a way that during the entrance of the guide, the slide (1) moves in one direction on the track (2) and on exiting it does so in the opposite direction, the retainer consists of a rod (5) which is housed in an orifice (6) of the slide perpendicular to the track (2) and which lines up with a blind orifice (10) on the track, precisely at the moment when the guide (3) exits the slide (1), the rod being aided by a spring (11) which tends to cause it to protrude constantly on the track (2) and against whose spring operates a rocker arm (14) which, also tending to enter the housing (4) of the slide, is activated by the same guide (3) when it is located in the housing of the slide.

Description: The invention herein refers to a retainer system, i . e . a system of temporary retention for a plastic injection mould slide with a retainer which is appropriately positioned in the said slide, allowing the connection of the same to the corresponding track and keeping it in a stable position, particularly whilst opening the mould. BACKGROUND OF THE INVENTION As we know, in the field of injection moulds the slides run along a track, the slides having holes which accommodate guides attached to the other piece of the mould, in such a way that during the manoeuvre of opening the said mould the aforementioned guides separate completely from the slides, which must remain in a stable position on the corresponding tracks once the guides have departed from them. To achieve this effect, several solutions exist, such as one where the connection of the slide to the track is achieved by means of magnets, a solution which is particularly ideal when dealing with small slides, and another where retainers are used in the form of pegs which, when fixed to the slide, operate on a pivot which is duly connected to the track, causing the required retention. In practice, these retainers take the form of a type of pincers, having two articulated arms, between which there is an open, circular housing, which operates in conjunction with the aforementioned pivot, its arms separating to allow to entrance of the pivot in the housing, bearing the pressure of the interior springs. This structurally very complex and consequently very expensive solution, implies a very significant volume, which makes it necessary to have a rather complex mechanism on the track base, to house the retainer, which also directly influences the cost of the equipment, as well as causing functional inaccuracies. In an effort to avoid this problem, the same applicant is the holder of Utility Model DE-U-8 701 679, in which a retainer system is described for injection mould slides and plates which takes the shape of a simple, single, flat piece of flexible material, preferably tempered steel, in which there is a small nucleus on one end, which has an orifice with a countersunk opening, in which enters a single screw to connect the aforementioned piece to the slide, a nucleus from which protrude two flexible, parallel arms which take the shape of a type of peg or clip connecting the retainer to the pivot incorporated in the track. This solution, may only require minimal space for installing the retainer and, furthermore, allows for quick and simple installation, as with the aforementioned system in the form of pincers, it is only viable for relatively lightweight slides, of up to around 20 kg, so for heavier weights it is necessary to use several retainers superposed or adequately distributed to carry out their function. On the other hand, the existence of the German Utility Model number DE 29709018 U is known, in which a plastic injection slide retainer system in accordance with the preamble of claim 1 is described whereby a retainer is situated in the lower part of the slide, i.e. in contact with the track. SPECIFICATION OF THE INVENTION The present invention proposes a retainer system in accordance with claim 1. The retainer system of the proposed invention specifically uses a slide with a housing which is at an angle in relation to the direction of movement of a guide at the same angle, so that the movement of the guide in the hollow of the slide at the same time causes the movement of the slide on the corresponding track. Thus, with this basic structure, the retainer which the invention proposes takes the form of a rod, housed in an orifice of the slide, perpendicular to the track, and with the movement of the slide, comes into line with a blind orifice drilled into the aforementioned track, this taking place specifically at the moment in which the slide is free of the guide pulling it. The aforementioned rod has one end with a shorter diameter, the opposite end to the_track, on which there is a spring which is constantly pushing the rod against the track, while its upper end has a transversal pivot which is operated by a rocker arm which is fitted in a way that it swivels on a support implanted and fixed to the slide, the rocker arm which, on the opposite end to that which operates on the aforementioned pivot, has a pulley wheel which by the effect of the aforementioned spring also tends to protrude into the interior of the slide housing and, consequently colliding with the active line of the guide, when the said guide is located inside the aforementioned housing. In this way, while the guide is acting on the slide, the rod is retracted or inoperative, and when the guide leaves the slide support and leaves the rocker arm free, at the moment when the retaining rod is in line with the shallow orifice in the track, the spring causes the axial projection of the said rod, its entrance into the aforementioned blind orifice and the consequent stoppage of the slide. DESCRIPTION OF THE DRAWINGS To complement the specification being carried out and with the aim of giving a greater understanding of the invention characteristics, in accordance with a preferred example of practical embodiment, and as an integral part of the aforementioned specification, it is accompanied by a set of illustrative and non-restrictive drawings, which represent the following: Figure 1.- Shows a lateral view and cutaway schematic representation of part of a plastic injection mould slide, and the corresponding track, having a retainer which stops the slide which constitutes the object of the invention herein. Figure 2.- Shows view from above with detail of the equipment represented in the previous Figure. Figure 3.- Shows several sequences of the mechanism, with a representation similar to that of Figure 1, the first one showing the slide running on the track, the second in the retained position and the third returning to the original position. Figure 4.- Shows a similar representation to that of Figure 1, a front view and cutaway of the equipment of the said figure, in accordance with a variant on the practical embodiment in which the means of retaining the slide on the track are positioned at a difference of 90° in relation to Figure 1. Figure 5.- Finally, shows a lateral view of the detail represented in the previous Figure, in which we can see how the aforementioned means of retention are hidden behind the guide, being positioned perpendicularly to the imaginary path of movement of the latter. PREFERRED EMBODIMENT OF THE INVENTION In view of the Figures described, it can be seen how the retainer is intended for a slide (1), which runs along a track (2), pushed by a slanted guide (3), which enters a housing (4), also at an angle, of the aforementioned slide (1), so that during the phase of the guide (3) entering the slide (1), the slide will move in a specific direction, that of the first sequence in Figure 3, whilst when the said guide (3) moves in the opposite direction, it also pulls the slide (1) in the opposite direction, in accordance with the third sequence in Figure 3. So, the retainer of the invention takes the shape of a rod (5), which is housed in the interior of an orifice (6) perpendicular to and opening out on to the track (2), its opposite end being enlarged (7) in which a support (9) for the said rod (5) can be coupled and secured by means of a screw (8), a rod (5) which depending on the position of the slide (1), lines up with and enters a blind orifice (10) incorporated into the track (2), precisely at the moment in which the guide (3) and the slide (1) separate, in accordance with the intermediate sequence in Figure 3. The rod (5) tends to constantly move against the track (2) as a result of a spring (11) fixed on the rod, (5) on the end which has a smaller diameter (5'), and which rests its other end on a bushing (12) suitably connected to the support (9), a bushing from which the aforementioned end (5') of the rod (5) protrudes to receive a transversal pivot (13) through which it is connected to a rocker arm (14), with a rocker shaft (15) located in its centre and having a pulley wheel (16) which, as a result of the spring (11) tends to constantly enter the housing (4) of the slide (1) in which the guide (3) operates, the established casing for these elements being in the hollow of the aforementioned support (9), opening out onto said housing (4). In accordance with this structuring, the mechanisms function is as follows: When the slide (1) is in motion, the guide, indicated with an arrow in the first sequence of Figure 3, on moving outwards from the hollow of the housing (4) of the said slide, causes the required movement of the same, maintaining the retainer inoperative hence the rod (5), pushed by the spring (11) rests on the track (2) and slides along it. In the critical moment, when the guide (3) leaves the housing (4) of the slide (1), the moment when the said slide must remain fixed and retained, the rod (5) is found to be in line with the blind orifice (10) of the track (2) and the rocker arm (14) is freed at the same time due to the absence of the guide (3), so that the rocker arm can move freely and does so as a result of the spring (11), at the same time as the rod (5), by the same result, enters into the blind orifice (10) blocking the slide (1) in relation to the track (2), as shown in the second sequence of Figure 3. In the manoeuvre of returning the slide (1), when the guide (3) enters the housing (4), it firstly collides with the pulley wheel (16) of the rocker arm (14), causing this to swivel and consequently the retraction of the rod (5), which thus leaves the blind ori f ice (10), unblocking the slide (1), as shown in the third sequence of Figure 3, and ready to be pulled in the direction of the arrow in the said sequence, due to the guide (3) entering the hollow of the housing (4). Optionally, and with the aim of avoiding the dead centre which occurs in the previous solution, it is proposed that both the rod (5) and the different related accessories adopt a lateral position in the equipment, i.e. both the orifice (6') of the slide (1) and the blind orifice of the guide, are positioned at 90° to the imaginary path on which the guide (3) moves, so that the pulley wheel (16) acting on the guide (3) works at right angles to the aforementioned path of movement of the said guide , as shown in Figures 4 and 5.

Claims: Plastic injection mould slide retainer system comprising a slide (1) moveable on the corresponding track (2) with the aid of a slanted pulling guide (3), acting on a slide housing (4) which is also slanted in relation to the aforementioned track (2), and a retainer, the retainer comprising a rod (5) which is housed in an orifice (6) of the slide (1) perpendicular to the track (2), the rod (5) which once freed from the slide (1) by the pulling guide (3) can line up with a blind orifice (10) on the track (2), in which it enters causing the blockage or retention of the slide (1) as a result of a spring (11) which tends to force it in this direction, a rod (5) aided by a rocker arm (14), on the end opposite to the track (2), activated by the same guide (3) when it enters the slide housing (4), and the retainer being arranged in a hollow support (9) of the slide (1), characterised in that the hollow support (9) wherein the retainer is arranged, is implanted in the upper side of the slide (1), the hollow support (9) having an opening on to the slide housing (4) in which the rocker arm (14) is directly operable by the pulling guide (3) when it enters the slide housing (4). Plastic injection mould slide retainer system according to claim 1, characterised in that the rod (5), on the end opposite to the track (2) has an area (5') of reduced diameter, causing a ridge on which the spring (11) acts, which on its other end rests on a bushing (12) connected to the hollow support (9) and secured to it by a screw (8). Plastic injection mould slide retainer system, according to previous claims, characterised in that the rocker arm (14) is fitted allowing movement by means of an intermediate shaft (15) on the hollow support (9), it is operable by means of one of its ends on a transversal pivot (13) connected to the rod (5), and on its other end has a pulley wheel (16). Plastic injection mould slide retainer system according to claim 3, characterised in that both the orifice (6) of the slide (1) and the blind orifice (10) of the track (2) are positioned in a way that the rocker arm (14) and consequently the pulley wheel (16), attack the pulling guide (3) within its imaginary path of movement. Plastic injection mould slide retainer system according to claim 3, characterised in that both the orifice (6) of the slide (1) and the blind orifice (10) of the track (2) are positioned in a way that the rocker arm (14) and consequently the pulley wheel (16), attack the pulling guide (3) within a path perpendicular to its imaginary path of movement.

Inventors: NAVARRA PRUNA ALBERTO, NAVARRA PRUNA, ALBERTO
Applicants: NAVARRA PRUNA ALBERTO, NAVARRA PRUNA, ALBERTO
Application year: 2001
Main classification: B29C45
IPC codes: B29C45