CH641383A5 - EXPANSION HEAD OF AN APPARATUS FOR FLARING OR WIDENING THE END OF THE TUBES. - Google Patents

Abstract

1. Expansion head for an apparatus for flaring up or widening the ends of tubes, comprising essentially a body (1) with shifting means (2-2**1 ) for a chuck (3) the tapering end (3**1 ) of which is acting urgingly within the corresponding bore (5**3 ) of a plurality of independent concentric jaws (5) in the form of sectors interconnected by a retaining elastic means (O) positioned within a circular groove (5**4 ) established underneath the common colla (5**5 ) for each one of the aforesaid jaws (5) in order to constitute the expansion head proper, the collar (5**5 ) of which is abutted within the shouldered bore (4**3 ) of a socket (4) secured at the end of the body (1), characterized in that all the retaining means (O and A) of the jaws (5) are disposed underneath their common collar (5**5 ) to permit an extensive range of dimensions of the jaws (5) with the same socket (4), the elastic but collapsible means (A) of said jaws (5) relative to the bottom of said socket (4) being centered and positioned within a groove (5**7 ) of the aforesaid jaws (5) while protruding alternately from the external diameter of the expansion head (T) for retaining same axially and vertically in combination on the one hand with the lower face (4**4 ) of the socket (4) and on the other hand with the opposite collar (5**5 ) abutted on the inside shouldering (4**3 ) of said socket (4).

Description

The invention relates to an expansion head of an apparatus for flaring or widening the ends of the tubes.

It is well known to produce devices for flaring the ends of the tubes. Generally, these devices comprise a body with means for displacement by cam and lever of a mandrel whose conical end acts in thrust in the corresponding bore of a plurality of jaws in the form of sectors connected to each other by elastic means to form an expansion head capable of cooperating externally with the ends of the tubes to be flared. Most often, the expansion head thus formed is provided with a terminal support flange in the bottom of the bore and with a socket fixedly mounted at the end of the body.

Thus produced, the expansion heads, in particular, have certain drawbacks, essentially caused by the positioning and the very conformation of the elastic means ensuring the retention between them of the jaws to constitute the expansion head.

Most often, this elastic means is housed and positioned in a groove formed circularly at the periphery of the collar of the sleeve so that said elastic means considerably limits the dimensioning of the jaws of the expansion head for the same sleeve. It is necessary to have several ranges of sockets corresponding to different ranges of dimensions of the jaws of the expansion head. This results in significant cost and storage.

Another major drawback is caused by the construction of the elastic means which does not allow easy disassembly and reassembly of the assembly of the expansion head for the exchange or repair of one or more jaws of said head, both on site and in the factory. Indeed, the various known elastic means exert their retaining action in a circumferential and linear manner around the jaw games, thus causing an imbalance of the applied forces which always tends to reject the jaws with respect to each other.

The invention has set itself the aim of remedying these drawbacks and is remarkable in that the elastic jaw retaining means is positioned in a circular groove established below the common flange of each jaw to allow a range of dimensions jaws with the same socket, and in that it has a retractable elastic retaining means relative to the bottom of the socket, while allowing its displacement in expansion or shrinkage by the action of the mandrel and also its disassembly.

The elastic means ensuring the retention of the jaws therebetween may be an open spring, which has a plane bearing face so as to no longer exert a linear circumferential action on the entire set of jaws, but a circumferential surface action forming mounted, which ensures perfect stability of the jaws during disassembly or reassembly.

On the other hand, it is possible to use the opening or slot of the elastic jaw retaining means for the introduction of a clamp with a view to its spacing for its assembly and / or disassembly.

To fix the subject of the invention, without however limiting it, in the attached drawings, given by way of example:

fig. 1 is a perspective view, before mounting in the socket of an expansion head according to the invention, itself shown before the positioning of the various elastic retaining means;

fig. 2 is a perspective view of the expansion head alone after mounting of the elastic retaining means;

fig. 3 is a perspective view of one of the jaws constituting, after assembly with its counterparts, the expansion head;

fig. 4 is a view in longitudinal section showing an expansion head according to the invention housed in a socket, before it is mounted at the end of the body of the device to be flared;

fig. 5 is a view similar to FIG. 4 after assembly of the socket / expansion head assembly, at the end of the device body;

fig. 6 is a cross-sectional view along line 6-6 of FIG. 4;

fig. 7 is a cross-sectional view taken along line 7-7 of FIG. 5;

fig. 8, 9 and 10 are partial sectional views on a larger scale, showing different embodiments of the elastic means for retaining the jaws therebetween.

In order to make the object of the invention more concrete, it is now described in a nonlimiting manner, with reference to the sets of figures in the drawings.

It can be seen, in particular in FIGS. 4 and 5, an apparatus of any common type for flaring ends of tubes. Briefly, it comprises a body 1 with displacement means by cam 21 and lever 2, of a mandrel 3 whose conical end 31 acts in thrust on an expansion head T housed inside a socket 4 fixed at the end of the body 1. In a known manner, the sleeve 4 is tapped at 41 to be screwed onto the external thread 11 of the body 1. Coaxially with the thread 41, the lower part of the sleeve 4 is drilled at 42 a hole with a diameter less than said tapping to form a shoulder 44 allowing the positioning, passage and overflow of the expansion head T.

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641,383

The expansion head T is produced from several jaws 5 (FIG. 3), generally six, in the form of sectors which have, from their common internal edge 5 \, recesses 52 flared from their lower end, to constitute, after circular positioning of the sectors, a conical bore 53 (fig. 1 and 2). 5

As we have seen above, the different jaws 5 are held circularly between them by an elastic member 0.

The elastic means 0 for retaining the jaws 5 is positioned in a circular groove 54 of small diameter common to each jaw,

to constitute, after their circular coaxial mounting, a support flange 10 in the tapping bottom 41 of the socket 4.

This arrangement allows a wide range of jaw dimensions with the same socket.

Indeed, it is possible to reduce the thickness and diameter of the support flange 55 since the latter is no longer fitted, in opposition to the known prior embodiments, with the elastic retaining means 0 which occupied a certain space in the bottom of the tapping 4 'of the socket 4 and required sufficient dimensions of the collar for its positioning and centering. There is still a clearance J large enough to cover the various dimensional ranges of expansion heads.

On the other hand, in a particularly important way, the elastic means 0 for retaining the jaws S is a spring 6 with at least one flat support face 61 intended to cooperate with the corresponding bottom 56 of the groove 54 which constitutes a flat surface. 25

As a result, the flat support face 61 of the spring, in combination with the bottom of the groove 54, determines a support along a peripheral surface forming a scope for self-centering and the stable positioning in height of the jaws 5 while avoiding them, consequently, an imbalance in all directions, in particular during assembly (assembly and / or disassembly).

From this basic design of the spring 6, the only necessary and sufficient condition of which is to have an internal face of planar support 61, several shapes in section of the said spring can be envisaged as illustrated in no way restrictively in FIGS. 8, 9 and 10. The bottom of the groove 54 always remains flat, being parallel to the generatrices of the body of the expansion head T.

We also see, in particular in FIGS. 1 and 2, that the spring 6 is opened at 62 to give it a certain diametrical expansion when the mandrel 3 is pressed into the resulting bore 53 of the assembly of the jaws 5, with a view to their possible spacing. Similarly, the opening 62 of the spring 6 allows the introduction of a specially shaped clamp to allow its spacing with respect to the set of jaws for its assembly and / or disassembly.

Optionally, the spring 6, always with an internal face 45 of planar support, may not be open, on the sole condition that it is made of a material capable of undergoing diametrical expansion by elasticity, in particular for a assembly and disassembly, on the one hand, and so as not to hinder the spacing of the jaws 5, on the other hand.

According to another characteristic, provision is made to equip the expansion head T with a retractable retaining means with respect to the underside 43 of the socket 4 while allowing its displacement in expansion or shrinkage during the action of the mandrel 3, and also its disassembly. For this purpose, an elastic member A is suitably profiled to, on the one hand, center in an external groove 57 common to the jaws 5 and, on the other hand, alternately extend beyond the outside diameter of the head T, in view ensuring its axial retention in combination with the underside 43 of the socket 4 and the support flange 5S of said jaws 5.

According to a particularly advantageous embodiment, the elastic member A is a pin-shaped open spring 7 of pentagonal shape (FIGS. 1 and 2), the sides 1 of which are centered and positioned in the groove 57 and the projecting vertices 72 of which extend beyond the outside diameter of the socket 4, to be applied to the underside 43 of said socket 4 (fig. 4 and 6) when the flange 55 is in abutment in the bottom of the thread 41. It is quite obvious that the groove 57 is machined at a distance d from below the flange 55, equal to the depth of the hole 42 in the socket 4. There is therefore no play in height (FIGS. 4 and 5).

As before, the hairpin spring 7 is open so as not to harm the diametrical expansion of the jaws 5; for this purpose, in a preferred manner, the spring 7 is split in line with one of its vertices 71. The pentagonal shape of the spring 7 is preferred, although not limiting.

It is obvious that, in the case of large expansion heads and sockets, the latter can cooperate with an intermediate ring capable of being screwed at the end of the body 1 of the device; such arrangements are well known to those skilled in the art.

The advantages are apparent from the description; in particular, we emphasize:

- The possibility of using the same socket for several dimensional ranges of jaw games by the reduced dimensions of the flange in particular, which only aims to ensure the retention of the expansion head inside the socket;

- Self-centering and stable positioning in height of the jaws, avoiding an imbalance in all directions, conferred by the strictly flat internal face of the retaining spring of said jaws;

- maintaining and positioning the expansion head in height relative to the bushing;

- The possibilities of separating the expansion head from the socket without removing the elastic means connecting the jaws to each other.

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2 sheets of drawings

Claims (6)

641,383 1. Expansion head of an apparatus for flaring or widening the ends of the tubes and comprising a body (1) with means of displacement (2-21) of a mandrel (3) whose conical end (31) acts pushed into the corresponding bore (53) of a plurality of independent concentric jaws (5) in the form of sectors connected by elastic means (0) to form the expansion head (T) with support flange (55 ) in the bore of a socket (4) fixed at the end of the body (1) of the device, characterized in that the elastic means (0) for retaining the jaws is positioned in a circular groove (54) established at the below the common flange (55) of each jaw (5) to allow a range of jaw dimensions with the same socket, and in that it has a retractable elastic retaining means (A) relative to the bottom of the sleeve (4), while allowing its displacement in expansion or shrinkage by the action of the mandrel (0) and also its disassembly. 2. Expansion head according to claim 1, characterized in that the means for retaining (0) the jaws (5) is an open annular spring (6) with at least one flat bearing surface (61) cooperating with the corresponding bottom (56) of the groove (54) to obtain a support along a peripheral surface forming a scope for self-centering and stable positioning in height of the jaws (5) avoiding an imbalance in all directions, in particular in assembly course. 2 3. Expansion head according to claim 1, characterized in that the retractable elastic retaining means (A) of the jaws (5) relative to the sleeve (4), is profiled to, on the one hand, center and position in a groove (57) common to the jaws (5) and, on the other hand, alternately extend beyond the outside diameter of the head in order to ensure its axial retention in height in combination with the bottom face (43) of the sleeve (4), and the flange (5S) resting in the bottom of the bore of said sleeve (4). 4. Expansion head according to one of claims 1 or 3, characterized in that the retractable elastic retaining means (A) of the jaws (5) relative to the sleeve (4), is an open pin spring ( 7) of pentagonal shape, the sides (71) of which are centered and positioned in the groove (57), and the projecting vertices (72) of which extend beyond the outside diameter of the sleeve to be applied to the underside (43 ) of the socket (4). 5. Expansion head according to one of claims 1 or 2, characterized in that the spring (6) is open (62) to allow in particular the introduction of a clamp to separate the spring from the set of jaws (5 ) for its assembly and / or disassembly. 6. Expansion head according to one of claims 1 or 2, characterized in that the bottom of the groove (5+) is plane being parallel to the generatrices of the body of said expansion head.