TECHNICAL FIELD

The present invention relates to metallic pipe head forming and finishing operations, and concerns a multipurpose head forming and finishing apparatus.

BACKGROUND ART

Currently, many so-called head forming and finishing apparatuses are known that carry out flaring, widening, narrowing and other similar head forming and finishing or modifying operations on the heads of pipes.

These head forming and finishing apparatuses basically include a clamp for grabbing the pipe near the head thereof to be worked, and means for driving of a punch tool, mobile in a direction axial to the pipe held by the clamp.

The clamp includes a stationary jaw, supported by the apparatus base, and a mobile jaw moved vertically in such a manner as to be closed on the stationary jaw; the mobile jaw is fastened to a cross-piece displaced, via a couple of lateral vertical connecting rods, by an oil-pressure operated cylinder situated under the working surface.

The traditional head forming and finishing apparatuses have a very bulky structure and are little functional, particularly as the resistance to the stresses is concerned.

In fact, these apparatuses are equipped with

very big motors, have long working cycles, with a remarkable energy consumption, and their tool set-up time is long, as well.

DISCLOSURE OF THE INVENTION

The object of the present invention is to propose a multipurpose head forming and finishing apparatus, that is capable of performing an elevated number of operations, has small dimensions, features high resistance to stresses and is very functional.

The above mentioned object is achieved, in accordance with the claims, by means of a multipurpose head forming and finishing apparatus, that includes: a support frame forming on a horizontal plane a kind of arc endowed with a pair of arms symmetrical with respect to a median vertical plane,- a clamp, operated in a horizontal direction, for gripping a pipe in proximity of a head to be worked, and including a stationary jaw and a mobile jaw, connected respectively to said arms of the support frame and aimed at being closed on said plane of median symmetry,- means for operating a tool along a direction axial with respect to said pipe gripped by said clamp.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the invention will be better understood from the following description, with particular reference to the attached drawings, in which:

- Fig. 1 shows a schematic plan view of the subject head forming and finishing apparatus;

- Fig. 2 shows a corresponding front view of the apparatus; - Fig. 3 shows a detailed plan view of the operation zone of the apparatus;

- Fig. 4 shows a corresponding sectional view of the apparatus taken along a vertical transversal plane,-

- Figs. 5 and 6 show plan views of the apparatus equipped with particular head forming and finishing tools, with some parts cross-sectioned;

- Figs. 7 and 8 show respectively a side and front view of a support carriage of the subject apparatus,-

- Figs. 9 and 10 show corresponding views of a stationary frame of the apparatus support;

- Figs. 11, 12 and 13 show respectively a side, front and plan view of a different embodiment of the support carriage of the apparatus,-

- Figs. 14,15,16 and 17 plan views of the apparatus equipped with other particular head forming and finishing tools, with some parts cross-sectioned.

BEST MODE OF CARRYING OUT THE INVENTION

With reference to the aforesaid Figures, numeral 1 generally indicates the head forming and finishing apparatus that performs forming and finishing operations on the heads of a pipe 2. The apparatus 1 includes a support frame 3 featuring a kind of arc that extends on a horizontal plane; in particular, this frame defines a couple of arms 3a,3b symmetrical with respect to a median vertical plane. The jaws of a clamp 4, aimed at gripping the pipe 2 in proximity of the head to work, are

fastened to the arms 3a, 3b of the support frame 3.

The clamp 4 is operated according to a horizontal direction, in such a manner as to close the jaws on a plane coincident with the said median vertical symmetry plane.

More precisely, a stationary jaw 5 of the clamp 4 is rigidly fastened to the first arm 3a of the support frame; while a mobile facing jaw 6 is guided slidingly on the second arm 3b according to a horizontal direction transversal to the aforesaid median symmetry plane.

In fact, the mobile jaw 6 is fastened to a plate 7 fixed to the free extremity of a couple of stems 8 that are slidably guided through the arm 3b of the support frame 3 and are operated by a double action actuating member 9, for instance an oil-pressure operated type device, integral with the same arm 3b.

Respective prismatic means 10,11, are fixed to the jaws 5, 6 of the clamp 4, and are set in sliding engagement with respective vertical prismatic guides 12,13, which have a shape matching therewith machined in a spacing plate 14 and in the said plate 7 (see Figs. 3 and 4) . The spacing plate 14 features a prismatic slide 15, similar to the previous ones, for engagement of a corresponding vertical guide 16, made on another plate 17 protruding from the arm 3a of the support frame 3. Respective stop members.18,19, which define vertical positions of the jaws 5,6 of the clamp 4, are also fastened to the plates 14 and 7 by means of traditional screws, in the region of the guides 12,13, (Fig.4). Instead, the spacing plate 14 is brought in abutment onto a stop 20 fixed to the plate 17. The

spacing plate 14 can be removed in order to work pipes of bigger diameter, that need a clamp equipped with jaws of bigger dimensions.

Obviously, in this case, the stationary jaw 5 engages directly the guide 16 of the plate 17.

An actuating means 21, also made integral with the support frame 3, operates a tool that performs the head forming and finishing operations. This tool is located on the said median plane and along a direction axial with respect to the pipe 2 gripped by the clamp 4.

This actuating means 21 is substantially constituted by an oil-pressure operated cylinder provided with a stem 22, mobile according to the aforesaid axial direction.

The fore and rear stop positions of the stem 22, are defined by a couple of proximity sensors 23,24, mounted in adjustable position along a bar 25 that extends from the support frame 3. The head forming and finishing tool is, for instance a punch 26 fixed, by means of a quick coupling, to the front end of the stem 22.

Therefore, operating the active stroke of the stem 22 causes the axial penetration of the punch 26 in the pipe 2 gripped by the clamp 4, provoking the widening of the head 2a, as seen in Fig.3.

In order to mount the pipe 2 on the head forming and finishing apparatus, first the clamp 4 is opened, by moving the plate 7 that carries the mobile jaw 6, as indicated with the broken line 7a in Fig.l. This allows insertion of the pipe 2, and then the mobile jaw 6 is closed onto the stationary jaw 5 and the pipe 2 is gripped therebeteween.

The clamp 4, operated horizontally, holds the pipe 2 in a perfect symmetry in the support frame 3, that guarantees optimal conditions of stress

resistance. Therefore the clamp 4 can, in closing step, support considerable stresses, up to the limit of elastic deformation of the pipe to work.

It is to be noted that if the frame becomes deformed because of the said symmetry, the pipe would anyway kept coaxial with the stem 22 carrying the tool.

Therefore, the constant quality of the pipes worked in this way is guaranteed. The horizontally operated clamp 4 allows the internal zone of the jaws to be easily seen in the opening step, for a better positioning of the pipe to work.

The apparatus allows to perform an elevated number of operations, due to possibility of easy substitution of the tools on the stem 22 of the operating means 21.

Besides tools working in compression, such as the illustrated punch 26, the apparatus can also use tools working in traction. It is also possible to use particular tools equipped with dies that can be mounted on the support frame of the apparatus.

Fig. 5, for instance, shows an expanding tool, indicated generally with numeral 27, aimed at widening the head of the pipe 2. This expanding tool 27 features, in known way, a series of radial sectors 28 mounted in a circle around a wedge 29, and held in place by a support 30 that is connected with the guides 12,13 of the support frame 3, instead of the jaws of the clamp 4 illustrated previously.

The wedge 29 is fixed coaxially to the stem 22 and operated thereby, in such a manner as to be retracted with respect to the support 30, as illustrated with broken line 29a.

In this configuration, the radial sectors 28

are near to each other, due to the action of suitable elastic means, therefore it is possible to introduce therein the pipe 2 to be worked.

The following active stroke of the stem 22, i.e. the stroke of penetration of the wedge 29, determines the forced expansion of the radial sectors 28 and widening of the head 2a of the pipe.

Fig. 6 shows a narrowing tool, indicated generally with 31, aimed at narrowing of the head 2a of the pipe 2.

This narrowing tool 31 features, in known manner, a series of radial sectors 32, externally forming a wedge, mounted in a circle inside a ring-like support 33 complementary thereto,- the support 33 is connected to the guides 12, 13 of the support frame 3, instead of the jaws of the clamp 4.

The radial sectors 32 are made to expand by an elastic means 34 mounted on a disk-like plate 35 that is fixed to a flange 36 designed for connection to the stem 22.

Therefore, the radial sectors 32 can be retracted from the ring-like support 33, as indicated with broken line 32a, hence it is possible to introduce the pipe 2 to be worked. The following active stroke of the stem 22 pushes the radial sectors 32 closer to each other and the consequently makes the head 2a of the pipe narrow.

With reference to Fig.14, a head facing tool is connected to the stem 96 that, in this case, is also driven in axial rotation R by means of a known driving device, not shown.

The facing tool includes, in the shown embodiment, a flat cutting bit 99, and a cornering bit 98. The flat cutting bit faces the head of the pipe _^ 2 gripped between the jaws 85,86 fixed to the

plates 87,97, while the stem 96 is also pushed in direction L.

The cornering bit cuts the corners of the faced head. In Fig.15 there is shown a spin cone-shaping tool mounted on the stem 91, also turned axially in direction R. The spin cone-shaping tool includes a arc-shaped plate 88 whose ends support conical rollers 84, 94 set with convergent axes. The intersection point of the conical rollers axes lays on the axis of the pipe 2.

When the stem is set into rotation R and pushed along direction L, the cone-shaping tool inserts into the head of the pipe 2, gripped by the clamp, and turn after turn it shapes the pipe head giving it a conical shape.

For better operation, the jaws are in this case shaped so as to match the cone being formed at the head of the pipe. For instance, the rim of the hole defined by the jaws ad facing the cone-shaping tool is countersunk.

With reference to Fig.16, the apparatus is in this case equipped with a spin cutting tool 83.

The stem 82 is rotated in direction R and displaced in direction L until it enters the head of the pipe 2, gripped by the jaws 85,86 fixed to the plates 87,97, until it reaches the point where the pipe is to be cut.

Then the stem 82 is imparted a transversal progressive motion in direction E so as to take an eccentric position with respect to the stem and pipe axes. Rotation of the stem will thus cut the pipe.

This gives a better appearance to the pipe head due to cutting from inside, while the circular shape is perfectly maintained by the grip action of the clamp.

- 9

Another embodiment is shown in Fig.17, where the shaping tool 93 is similar to the one of Fig.16, but instead of cutting it makes a circular groove in the inner surface of the pipe. For this operation the tool 93 has a curved profile and the jaws feature a circular groove that matches the tool profile.

After that the pipe 2 has been gripped by the clamp, the shaping tool is positioned in alignment with the groove made in the jaws by displacement of the stem 92 along direction L.

Then the stem is rotated in direction R and set eccentric by displacement thereof in direction E, until the groove is made in the pipe. To improve the operation, a spacing element, not shown for clarity, can be positioned between the rim of the pipe 2 and the shank of the shaping tool 93.

The head forming and finishing apparatus 1 is suitably mounted on a carriage 37, designed to allow an easy transport thereof, as shown in Figs. 7 and 8.

This carriage 37 basically includes a support structure 38 equipped with a couple of fore wheels 39 and, at the back, with a towing or rudder means

40, that supports a central pivoting wheel 42 by means of a fork 41.

The back wheel 42 and the rudder 40 form a lever mechanism, designed to lift the carriage 37 from the support on the feet 46, loading the weight on the same wheel 42.

When the rudder 40 is not pushed downwards, the ' weight returns onto the feet 46, and consequently, the structure 38 has firm support. The structure 38 usefully supports an oil-pressure control unit 43 for supplying oil under

pressure to the apparatus and making it completely autonomous.

If the head forming and finishing apparatus 1 is not equipped with an autonomous oil-pressure control unit, it is obviously provided with conventional quick connection means for connection to external feeding means.

Naturally, it is possible to use the said structure 38 as fixed support for the apparatus 1, in particular if it is provided with the oil-pressure control unit 43, as shown in Figs. 9 and 10.

Figs. 11, 12 and 13 show an innovative embodiment of the support carriage 37 of the head forming and finishing apparatus 1, in which the structure is made of modular elements 44 constituted by tubular elements with circular section, suitably folded up,- these tubular elements 44 are rigidly fastened by means of brackets 45. A similar tubular element, fastened by means of the aforesaid bracket 45, carries the fore wheels 39.

Obviously, also in this case the carriage 37 can support the oil-pressure control unit 43 for feeding of the apparatus.

Therefore, the object apparatus resolves in an innovative manner the problem of a precise forming and/or finishing of the head of pipes, having a simplified solid structure, reduced dimensions, and being easy to use.

The apparatus allows to perform an elevated number of operations, and in practice can have a universal use with the known tools.

It is understood that what above has been described as a pure example, non limitative, therefore all possible constructive variations

remain under protection of the present technical solution, as described above and claimed hereinafter.