Method and device for making grooves in a tin body

Description

[0001] The invention relates to a method and an apparatus for pressing at least one in- or outwardly protruding reinforcing ridge in the sleeve of a tin body, that means to a method and a device of the kind as disclosed in US-A-4,380,165. The method published by this patent specification comprises a step of inserting the tin body axially into a gap left free between two similar radially spaced concentric closed curved or bent series of simultaneously radially reciprocatable stamps, the stamps of one series having on their faces confining said gap ridges which form together at least one row of longitudinally aligned ridges, the stamps of the other series having in their faces confining said gap grooves which form together at least one row of longitudinally aligned grooves registering with said ridges and the stamps of either series being provided with cam faces for cooperation with cam faces of respective axially reciprocatable control members, the cooperation of the cam faces of the stamps and those of the respective control members being such, as to ensure that the active strokes of said members have the effect of bringing the grooved stamps ahead of or simultaneously with the ridged stamps into engagement with the tin body, of blocking the radial disengagement movement of the grooved stamps and of forcing, by means of the ridged stamps, the tin body into the grooves of the grooved stamps, and subsequent steps of moving the control member of the grooved stamps axially to bring said stamps into engagement with the tin body and to block them in their positions of engagement, of moving the control member of the ridged stamps axially to force the tin body into the grooves of the blocked grooved stamps, of retracting the control members axially to enable the stamps of both series to be radially retracted from the tin body and of removing the tin body axially out of the gap left free again between the two series of radially retracted stamps.

[0002] In this known method cooperating bevelled cam faces provided on the grooved stamps and their control member are not only used for the conversion of the axial movement of said member into the radial movement of said stamps, but also for blocking said stamps in their positions of engagement with the tin body. This implies that both the radial displacement and the blocking of the grooved stamps depend on the exact adjustment of the end of the active axial stroke of said control member. This exact adjustment is in practice realized by means of stops. However, this way of defining the blocking end position of the control member in question has several disadvantages. Firstly, there is not much room to build such stops in. Secondly, the impact of the control member on the stops causes shocks in the apparatus which prevent high speeds of the actual pressing operation. Thirdly, the use of stops requires a resilient drive of the control member and such a drive in combination with stops present the possibility of rebounding, whereby the exact adjustment of the end of the active stroke of said member is affected which only can be prevented by relatively slow motion of the moving parts.

[0003] The invention has the object to improve this method and this is achieved in that only a first part of the active stroke of the control member of the grooved stamps is used to bring said stamps into engagement with the tin body, at the end of said part of the stroke the radial disengagement movement of said stamps is blocked and said blocking is maintained during the subsequent part of the stroke of said member. This improvement makes the length of the stroke of the control member of the grooved stamps independent of the blocking of said stamps, consequently noncritical, so that, even if stops at the end of the active stroke of said member should be used, the rebounding thereof by said stops, if kept within the second part of said stroke, would not have any effect on the blocking of the stamps in question. In many cases such stops may be dispensed with and this makes it possible to drive the control member of the grooved stamps positively, that means without the interposition of springs in the active direction. Due to these facts the speed of operation may be considerably increased.

[0004] The method can be carried out by an apparatus which, just as the apparatus described in US-A-4,380,165, comprises two similar radially spaced concentric closed curved or bent series of simultaneously radially reciprocatable stamps, the stamps of one series having on their faces confining the gap left free between the two series of stamps to receive the sleeve of a tin body ridges which form together at least one row of longitudinally aligned ridges, the stamps of the other series having in their faces confining said gap grooves which form together at least one row of longitudinally aligned grooves registering with said ridges, two axially movable control members, one for the simultaneous radial movement of the ridged stamps and one for the simultaneous radial movement of the grooved stamps, the ridged stamps on one hand and the respective control member on the other hand and the grooved stamps on one hand and the respective control member on the other hand being provided with cooperating cam faces, of which at least portions are bevelled for the conversion of the axial movements of the control members into radial movements of the two series of stamps towards one another in order to bring the grooved stamps into engagement with a tin body inserted into the said gap and to force by means of the ridges of the ridged stamps the tin body into the grooves of the grooved stamps, when the latter are held in their positions of engagement with the tin body, and the cam faces of the grooved stamps and their control member are also shaped to block the radial disengagement movement of the grooved stamps when loaded by the pressing ridged stamps, means for moving the control members axially and transporting means for moving a tin body axially into and out of the gap left between the two series of stamps after they have been radially moved away from one another, but said known device being improved in that of each pair of cooperating cam faces of which one is formed on a grooved stamp and the other one on the respective control member, at least one cam face has a bevelled portion for bringing said stamps into engagement with the inserted tin body during a first part of the active axial stroke of said control member and at least the other cam face has an axially extending portion for blocking the radial disengagement movement of said stamp at the end of said first part of the stroke and for maintaining said blocking during the subsequent part of said stroke.

[0005] The reinforcing ridge or ridges to be produced in the tin body may be other than purely circumferential, e.g. sloping, rhombic or otherwise different.

[0006] It appears to be advantageous to provide the improved apparatus with at least one axially movable spring loaded stop member for limiting the axial insertion of the tin body into the gap between the two series of stamps by said transporting means and for ejecting the tin body out of said gap after the pressing operation has been completed.

[0007] The invention will be described more fully with reference to the drawings, which show in

Figs. 1 to 4 different positions of stamps making grooves in a tin body when the method embodying the invention is being carried into effect,.

Fig. 5 schematically the supply of tins to the device embodying the invention,

Fig. 6 a sectional view of the device embodying the invention,

Fig. 7 on an enlarged scale part of the device of Fig. 6,

Fig. 8 a sectional view taken on the line VII-I-VIII in Fig. 7,

Fig. 9 is a sectional view like Fig. 7 in the closed position of the device,

Fig. 10 a sectional view taken on the line X-X in Fig. 9.

[0008] In accordance with the method embodying the invention (see Figs. 1 to 4) a tin body 1 is introduced between two stamps 2 and 3, one stamp 2 having ridges 4 and the other stamp 3 having grooves 5 registering with the ridges. The stamps 2 and 3 are driven by first and second driving means 6 and 7 respectively. The driving means 6 and 7 and the co-operating faces of the stamps 2 and 3 are formed so that during the first part of the axially directed stroke of the driving means 6, 7 (see Fig. 2) the stamps 2 and 3 are radially moved towards one another, whereas during the last part of the stroke (see Fig. 3) solely stamp 2 is radially moved and hence stamp 3 serves as a counter-bearing. The radial movement producing the grooves in the tin body 1 is, therefore, performed solely by stamp 2. After the formation of the grooves the driving means 6, 7 (see Fig. 4) move in opposite axial directions, the stamps 2 and 3 move radially in opposite senses and the tin body is again released.

[0009] Fig. 5 schematically shows the way in which tins 1 are fed to a device as shown in Figs. 6 and 7 in which the assembly of Figs. 1 to 4 is arranged. The tins (Fig. 5) are moved by a worm conveyor 8 in a feeder 9 into a device embodying the invention, which comprises in this embodiment six identical processing stations 10.

[0010] With the aid of the feeder 9 (see Fig. 6) a tin body 1 is moved to a processing station 10. The unit with the stamps is fixed by means of a cap nut 12 to a plunger housing 13 of an upper plunger 14. The plunger 14 is driven by a profiled upper disc 15 and a roller 16. The tin body 1 is moved upwards by means of a lower plunger 17 driven by a lower disc 18 into the unit 11. The tin body 1 is then enclosed in the feed head 19. The upper part can be set in height with the aid of a setting spindle 20. In this way the desired setting for the tin height can be chosen. Since the upper part is adjustable, there is no need for setting a lower part and hence of the feeding part of the tin bodies.

[0011] From Figs. 7 to 10 it will be apparent that the tin body 1 is introduced into the gap between the stamps 2 and 3 up to a resilient stop 22. After the process the spring 23 ensures the ejection of the tin body. The driving means for the stamps 2 and 3, and 6, 7 respectively and the part 24 are fastened to the plunger 14 with the interposition of a spring structure 25. The cylindrical part 21 serves as a guide for the moving parts. During the performance of a stroke of the plunger 14 the driving means 6 and 7 move the stamps 2 and 3 in a manner such that the stamps 3 move radially outwards and engage the tin body. The stroke of the driving means 7 is limited by the stop 26. During the remaining part of the stroke of the plunger 14 the driving means 6 for the stamps 2 are moved axially so that the stamps 2 perform a radially inward movement and make the grooves in the tin body 1, whilst the inner stamps 3 serve as counter-bearings. Subsequently the plunger 14 moves in the opposite axial direction so that again a gap is formed between the stamps 2 and 3. The tin body is then moved to the outside by the head provided with magnets.

[0012] Fig. 8 shows that the stamps 2 and 3 are disposed opposite one another in segments of a circle.

Claims

1. A method of pressing at least one in- or outwardly protruding reinforcing ridge in the sleeve of a tin body (1), said method comprising a step of inserting the tin body (1) axially into a gap left free between two similar radially spaced concentric closed curved or bent series of simultaneously radially reciprocatable stamps (2, 3), the stamps (2) of one series having on their faces confining said gap ridges (4) which form together at least one row of longitudinally aligned ridges, the stamps (3) of the other series having in their faces confining said gap grooves (5) which form together at least one row of longitudinally aligned grooves registering with said ridges, and the stamps (2, 3) of either series being provided with cam faces for cooperation with cam faces of respective axially reciprocatable control members (6, 7), the cooperation of the cam faces of the stamps (2, 3) and those of the respective control members (6, 7) being such as to ensure that the active strokes of said members (6, 7) have the effect of bringing the grooved stamps (3) ahead of or simultaneously with the ridged stamps (2) into engagement with the tin body (1), of blocking the radial disengagement movement of the grooved stamps, (3) and of forcing, by means of the ridged stamps (2), the tin body (1) into the grooves (5) of the grooved stamps (3), and subsequent steps of moving the control member (7) of the grooved stamps (3) axially to bring said stamps (3) into engagement with the tin body (1) and to block them in their positions of engagement, of moving the control member (6) of the ridged stamps (2) axially to force the tin body (1) into the grooves (5) of the blocked grooved stamps (3), of retracting the control members (6, 7) axially to enable the stamps (2, 3) of both series to be radially retracted from the tin body (1) and of removing the tin body (1) axially out of the gap left free again between the two series of radially retracted stamps (2, 3), characterized in that only a first part of the active stroke of the control member (7) of the grooved stamps (3) is used to bring said stamps (3) into engagement with the tin body (1), at the end of said part of the stroke the radial disengagement movement of said stamps (3) is blocked and said blocking is maintained during the subsequent part of the stroke of said member (7).

2. An apparatus for carrying out the method claimed in claim 1, said device comprising two similar radially spaced concentric closed curved or bent series of simultaneously radially reciprocatable stamps (2, 3), the stamps (2) of one series having on their faces confining the gap left free between the two series of stamps (2, 3) to receive the sleeve of a tin body (1) ridges (4) which form together at least one row of longitudinally aligned ridges, the stamps (3) of the other series having in their faces confining said gap grooves (5), which form together at least one row of longitudinally aligned grooves registering with said ridges, two axially movable control members (6, 7), one (6) for the simultaneous radial movement of the ridged stamps (2) and one (7) for the simultaneous radial movement of the grooved stamps (3), the ridged stamps (2) on one hand and the respective control member (6) on the other hand as well as the grooved stamps (3) on one hand and the respective control member (7) on the other hand being provided with cooperating cam faces, of which at least portions are bevelled for the conversion of the axial movements of the control members (6, 7) into radial movements of the two series of stamps (2, 3) towards one another in order to bring the grooved stamps (3) into engagement with a tin body (1) inserted into the said gap and to force by means of the ridges (4) of the ridged stamps (2) the tin body (1) into the grooves (5) of the grooved stamps (3), when the latter (3) are held in their positions of engagement with the tin body (1), and the cam faces of the grooved stamps (3) and their control member (7) are also shaped to block the radial disengagement movement of the grooved stamps (3) when loaded by the pressing ridged stamps (2), means (12-16, 24, 25) for moving the control members (6, 7) axially and transporting means (17, 18, 19) for moving a tin body (1) axially into and out of the gap left between the two series of stamps (2, 3) after they have been radially moved away from one another, characterized in that of each pair of cooperating cam faces, of which one is formed on a grooved stamp (3) and the other one on the respective control member (7), at least one cam face has a bevelled portion for bringing said stamp (3) into engagement with the inserted tin body (1) during a first part of the active axial stroke of said control member (7) and at least the other cam face has an axially extending portion for blocking the radial disengagement movement of said stamp (3) at the end of said first part of the stroke and for maintaining said blocking during the subsequent part of said stroke.

3. An apparatus as claimed in claim 2, characterized in the provision of at least one axially movable spring (23) loaded stop member (22) for limiting the axial insertion of the tin body (1) into the gap between the two series of stamps (2, 3) by said transporting means (17, 18, 19) and for ejecting the tin body (1) out of said gap after the pressing operation has been completed.

Ansprüche

1. Verfahren zum Einpressen zumindest einer nach innen oder außen vorspringenden, verstärkenden Rippe in die Hülse eines Dosendkörpers (1) mit folgenden Verfahrensschritten:

-Der Dosenkörper (1) wird axial in einen Spalt eingeführt, der zwischen zwei ähnlichen, konzentrisch geschlossenen, gekrümmten oder gebogenen Reihen von gleichzeitig radial hin und her bewegbaren Stempeln (2, 3) freigelassen wird, wobei

-die Stempel (2) einer Reihe auf ihren den Spalt bildenden Flächen mit Rippen (4) versehen sind, die zusammen zumindest eine Reihe von longitudinal ausgerichteten Rippen bilden,

-die Stempel (3) der anderen Reihe an ihren den Spalt bildenden Flächen mit Vertiefungen (5) versehen sind, die zusammen zumindest eine Reihe von longitudinal ausgerichteten, mit den Rippen fluchtenden Vertiefungen bilden,

-die Stempel (2, 3) beider Reihen mit Steuerflächen versehen sind, die mit Steuerflächen von jeweils axial hin und her bewegbaren Steuerteilen (6, 7) zusammenwirken,

-dieses Zusammenwirken der Steuerflächen der Stempel (2, 3) und der der jeweiligen Steuerteile (6, 7) derart ist, daß der aktive Hub dieser Teile (6, 7) folgende Effekte zeigt:

-Die mit den Vertiefungen versehenen Stempel (3) werden vor oder gleichzeitig mit den mit Rippen versehenen Stempeln (2) in Eingriff mit dem Dosenkörper (1) gebracht;

-die radiale Freigabebewegung der mit Vertiefungen versehenen Stempel (3) wird blockiert;

-mittels der mit Rippen versehenen Stempel (2) wird der Dosenkörper (1) in die Vertiefungen (5) der mit Vertiefungen versehenen Stempel (3) gepreßt;

-nachfolgend wird das Steuerteil (7) der mit Vertiefungen versehen Stempel (3) axial bewegt, um diese Stempel (3) in Eingriff mit dem Dosenkörper (1) zu bringen und um sie in der Eingriffsposition zu blockieren;

-das Steuerteil (6) der mit Rippen versehenen Stempel (2) wird axial bewegt, um den Dosenkörper (1) in die Vertiefungen (5) der blockierten, mit Vertiefungen versehenen Stempel einzupressen;

-die Steuerteile (6, 7) werden axial zurückgezogen, um ein radiales Zurückziehen der Stempel (2, 3) beider Reihen vom Dosenkörper (1) zu ermöglichen;

-der Dosenkörper (1) wird axial aus den zwischen den zwei Reihen der radial zurückgezogenen Stempel (2, 3) wieder freigelassenen Spalt entfernt, dadurch gekennzeichnet,

-daß nur ein ersten Abschnitt des aktiven Hubes des Steuerteiles (7) der mit Ausnehmungen versehenen Stempel (3) verwendet wird, um diese Stempel (3) in Eingriff mit dem Dosenkörper (1) zu bringen,

-daß am Ende dieses Abschnittes des Hubes die radiale Freigabebewegung dieser Stempel (3) blockiert wird und

-daß dieses Blockieren während des folgenden Abschnittes des Hubes dieses Teiles (7) aufrechterhalten wird.

2. Vorrichtung zum Durchführen des in Anspruch 1 angegebenen Verfahrens mit

-zwei ähnlichen, radial beabstandeten, konzentrisch geschlossenen, gekrümmten oder gebogenen Reihen von gleichzeitig radial hin und her bewegbaren Stempeln (2, 3), wobei

-die Stempel (2) der einen Reihe an ihren Flächen, die den zwischen den beiden Reihen der Stempel (2, 3) freigelassenen Spalt zur Aufnahme der Hülse eines Dosenkörpers (1) bilden, Rippen (4) aufweisen, die zusammen zumindest eine Reihe von longitudinal ausgerichteten Rippen bilden,

-die Stempel (3) der anderen Reihe an ihren den Spalt bildenden Flächen Vertiefungen (5) aufweisen, die zusammen zumindest eine Reihe von longitudinal ausgerichteten Vertiefungen bilden, die mit den Rippen fluchten,

-zwei axial bewegbare Steuerteile (6, 7) vorhanden sind,

-eines (6) für die gleichzeitige Radialbewegung der mit Rippen versehenen Stempel (2) und

-eines (7) für die gleichzeitige Radialbewegung der mit Vertiefungen versehenen Stempel (3),

-die mit Rippen versehenen Stempel (2) und das dazugehörige Steuerteil (6) einerseits und die mit Vertiefungen versehenen Stempel (3) und das dazugehörige Steuerteil (7) andererseits mit zusammenwirkenden Steuerflächen versehen sind, von denen zumindest Abschnitte zur Übertragung der axialen Bewgung der Steuerteile (6, 7) in die radiale, aufeinanderzu gerichteten Bewegungen der zwei Reihen der Stempel (2, 3) abgeschrägt sind,

-um die mit Vertiefungen versehenen Stempel (3) in Eingriff mit den in den Spalt eingeführten Dosenkörper (1) zu bringen und

-um mittels der Rippen (4) der mit Rippen versehenen Stempel (2) den Dosenkörper in die Vertiefungen (5) der mit Vertiefungen versehenen Stempel (3) zu pressen, wenn letztere in ihrer Eingriffsposition mit dem Dosenkörper (1) gehalten sind;

-die Steuerflächen der mit Vertiefungen versehenen Stempel (3) und ihres Steuerteiles (7) darüber hinaus so geformt sind, daß die radiale Freigabebewegung der mit Vertiefungen versehenen Stempel (3) blockiert wird, wenn diese durch die Preßbewegung der mit Rippen versehenen Stempel (2) belastet werden,

-Bauteile (12-16, 24, 25) zum axialen Bewegen der Steuerteile (6, 7) und

-Transportmittel (17, 18, 19) zum axialen Bewegen des Dosenkörpers (1) in den zwischen den beiden Reihen von Stempeln (2, 3) freigelassenen Spalt und wieder heraus, nachdem die Stempel (2, 3) radial auseinanderbewegt worden sind, vorgesehen sind, dadurch gekennzeichnet,

-daß bei jedem Paar von zusammenwirkenden Steuerflächen, von denen eine an den mit Vertiefungen versehenen Stempeln (3) und die andere an dem zugehörigen Steuerteil (7) angeordnet sind, zumindest eine Steuerfläche einen abgeschrägten Abschnitt aufweist, um die Stempel (3) in einem ersten Abschnitt des aktiven Axialhubes des Steuerteiles (7) in Eingriff mit dem eingeführten Dosenkörper (1) zu bringen und

-daß zumindest die andere Steuerfläche einen sich axial erstreckenden Abschnitt

-zum Blockieren der radialen Freigabebewegung des Stempels (3) am Ende des ersten Abschnittes des Hubes und

-zum Aufrechterhalten dieser Blockierung während des nachfolgenden Abschnittes des Hubes aufweist.

3. Vorrichtung nach Anspruch 2, dadurch gekennzeichnet, daß zumindest ein von einer axialen Feder (23) belastetes Anschlagteil (22) vorgesehen ist,

-um das axiale Einführen des Dosenkörpers (1 ) in den Spalt zwischen den beiden Reihen von Stempeln (2, 3) durch das Transportmittel (17, 18, 19) zu begrenzen und

-den Dosenkörper (1) aus dem Spalt auszuwerfen, nachdem der Preßvorgang vollendet wurde.

Revendications

1. Procédé pour presser au moins une arête de renforcement saillante vers l'intérieur ou l'extérieur dans le gaine d'un corps de boîte (1), ledit procédé comportant une étape d'insertion du corps de boîte (1) axialement dans un espace laissé libre entre deux séries similaires d'empreintes (2,3) pouvant se déplacer simultanément radialement selon un mouvement de va et vient, espacées radialement, concentriques fermées recourbées ou repliées, les empreintes d'une série comportant sur leur face délimitant ledit espace, des arêtes (4) qui forment ensemble au moins une rangée d'arêtes alignées longutinale- ment, les empreintes (3) de l'autre série comportant sur leur face délimitant ledit espace, des rainures (5) qui forment ensemble au moins une rangée de rainures alignées longitudinalement, coïncidant avec lesdites arêtes, et les empreintes (2, 3) de chaque série étant munies de faces en forme de came qui coopèrent avec des faces respectives en forme de came d'éléments de commande (6, 7) pouvant se déplacer axialement selon un mouvement de va et vient, la coopération des faces en forme de came des empreintes (2, 3) et celles des éléments de commande (6, 7) respectifs étant telle qu'elle assure que les courses actives desdits éléments (6, 7) ont pour effet de mettre les empreintes rainurées avant (3) ou simultanément avec les empreintes munies d'arêtes (2), en engagement avec le corps de boîte (1), de bloquer le mouvement de désengagement radial des empreintes rainurées (3) et de pousser, au moyen des empreintes munies d'arêtes (2) le corps de boîte (1) dans les rainures (5) des empreintes rainurées (3), et dans les étapes ultérieures de déplacer axialement l'élément de commande (7) des empreintes rainurées (3) pour mettre lesdites empreintes (3) en engagement avec le corps de boîte (1) et les bloquer dans leur position d'engagement, de déplacer axialement l'élément de commande (6) des empreintes munies d'arêtes (2) pour forcer le corps de boîte (1) dans les rainures (5) des empreintes rainurées bloquées, de rétracter uaxialement les éléments de commande (6, 7) pour permettre aux empreintes (2, 3) des deux série d'être rétractées radialement du corps de boîte (1) et d'extraire le corps de boîte (1) axialement de l'espace laissé libre à nouveau entre les deux séries d'empreintes rétractées radialement, caractérisé en ce que seulement une première partie de la course active de l'élément de commande (7) des empreintes rainurées (3) est utilisée pour mettre lesdites empreintes (3) en engagement avec le corps de boîte (1), le mouvement de désengagement radial desdites empreintes (3) étant bloqué à la fin de ladite partie de la course, et ledit blocage étant maintenu pendant la partie ultérieure de la course dudit élément (7).

2. Appareil pour la mise en oeuvre du procédé selon la revendication 1, ledit appareil comportant deux séries similaires d'empreintes (2, 3) espacées radialement, concentriques, fermées recourbées ou repliées, pouvant se déplacer simultanément selon un mouvement de va et vient, les empreintes (2) d'une série comportant sur leur face, délimitant l'espace laissé libre entre les deux séries d'empreintes (2, 3) pour recevoir la gaine d'un corps de boîte (1), des arêtes (4) qui forment ensemble au moins une rangée d'arêtes alignées longitudinalement, les empreintes (3) de l'autre série comportant sur leur face, délimitant ledit espace, des rainures (5) qui forment ensemble au moins une rangée de rainures alignées longitudinalement coïncidant avec lesdites arêtes, deux éléments de commande mobiles axialement (6, 7), l'un (6) pour le mouvement radial simultané des empreintes (2) munies d'arêtes et l'autre (7) pour le mouvement radial simultané des empreintes rainurées (3), les empreintes (2) munies d'arêtes d'une part et l'élément de commande respectif (6) d'autre part ainsi que les empreintes rainurées (3) d'une part et l'élément de commande respectif (7) d'autre part étant munis de faces en forme de came coopérant entre-elles, dont au moins des parties sont inclinées pour la conversion des mouvements axiaux des éléments de commande (6, 7) en des mouvements radiaux des deux séries d'empreintes (2, 3) l'une vers l'autre afin de mettre en engagement les empreintes rainurées (3) avec un corps de boîte (1) inséré dans ledit espace et pour pousser au moyen des arêtes (4) des empreintes (2) munies d'arêtes, le corps de boîte (1) dans les rainures (5) des empreintes (3) munies des rainures, lorsque ces dernières (3) sont maintenues dans leur position d'engagement avec le corps de boîte (1), et les faces en forme de came des empreintes rainurées (3) et leur élément de commande (7) ont également de formes telles qu'ils bloquent le mouvement de désengagement radial des empreintes rainurées (3) lorsqu'elles sont poussées par les empreintes (2) de pressage munies d'arêtes, des moyens (12, 16, 24, 25) pour déplacer les éléments de commande (6, 7) axialement et des moyens de transport (17, 18, 19) pour déplacer un corps de boîte (1) axialement dans et hors de l'espace laissé libre entre les deux séries d'empreintes (2, 3) après qu'elles ont été radialement séparées l'une de l'autre, caractérisé en ce que dans chaque paire de faces en forme de came qui coopérent entre elles, dont l'une est formée sur une empreinte rainurée (3) et l'autre sur l'élément de commande respectif (7), au moins une face en forme de came comporte une partie inclinée pour mettre ladite empreinte (3) en engagement avec le corps de boîte (1) inséré pendant une première partie de la course axiale active dudit élément de commande (7) et au moins l'autre face en forme de came comporte une partie s'étendant axialement pour bloquer le mouvement de désengagement radial de ladite empreinte (3) à la fin de ladite première partie de la course et pour maintenir ledit blocage pendant la partie ultérieure de ladite course.

3. Appareil selon la revendication 2, caractérisé en ce qu'il comporte au moins un élément de butée (22) déplaçable axialement, repoussé par ressort (23) pour limiter l'insertion axiale du corps de boîte (1) dans l'espace entre les deux séries d'empreintes (2, 3) par lesdits moyens de transport (17, 18, 19) et pour éjecter le corps de boîte (1) hors dudit espace après que l'opération de pressage a été réalisée.

Drawing