Patent Description:
More specifically, the present invention refers to an enhanced manually-operated or electrically-operated bending machine, and, even more specifically, it refers to a bending machine of a three-shaft type.

As is known, pipe bending or rounding aims at realizing well determined forms and/or patterns for a pipe (for instance, in the case of pipes used in heat exchangers or the like) or, also, at imparting greater strength to a tubular structure.

A tubular element bending or rounding process can be implemented by using either manually-operated bending machines or electrically-operated/motorized bending machines.

The bending machines typically known on the market and which reference will be made to in the present invention consist of so-called "three-driving-roller" bending machines, said grooved or race rollers being mounted on an equal number of shafts substantially arranged in a triangle or delta (Δ) configuration so as to define a passage for the profile to be bent/rounded that goes through said rollers and engages the grooves or races of said rollers which co-operate in defining a matrix-countermatrix system for the through-passing profile, which is progressively bent thanks to the pressure exerted thereon.

The traditional bending machines of the type mentioned above, if of the electrically-operated/motorized types, are characterized in having a greater power with respect to the manually-operated ones and allow to save workforce. However, because of the greater number of component parts, they tend to be rather bulky and expensive and, consequently, not to be in line with the needs and resources of users whose production is not a large scale one.

As a matter of fact, in electrically-operated/motorized bending machines, which possibly include two or three driving rollers, the rollers are driven by way of reducers or electric motors directly mounted on the shafts or, even, by way of electric motors in combination with actuators of an oil-pressure type.

The manually-operated bending machines don't have the drawbacks considered above when speaking about electrically-operated/motorized bending machines.

However, they are rather bulky, even though not so bulky as automatically-operated bending machines, because of the transmission systems used to transmit motion to the bending rollers.

Also, the traditional three-roller bending machines make it difficult to realize very short bending radii because, especially in the case of very thin pipes and profiles, they don't allow to minimize the deformations taking place in the pipes during the bending step due to the pressure exerted onto the pipe being enclosed between the movable roller and the fixed rollers.

A further drawback experienced in traditional three-roller bending machines and, in particular, in the manually-operated ones, is in that two or all three rollers thereof perform a driving function and, in the case of three driving rollers, it is complex to be able to adjust the position of the third roller in such a way that it is driving in any adjustment positions without having problems related to pipe slippages during the bending step.

An example of a traditional bending machine is described in document <CIT>, on which the preamble of independent claim <NUM> is based, which makes reference to a pipe bending machine comprising three bending rollers, a first roller of which is driven into rotation by way of an electric motor which transmits rotational motion to said one first roller by way of a pulley transmission (first pulley) which drives a gear transmission, the remaining two rollers being driven into rotation by way of the second pulley which drives a second roller into rotation, said further pulley receiving motion from the rotational motion of the shaft of the first roller, the third roller being driven into rotation by a third pulley, which receives motion from the second pulley and from a gear system.

An object of the present invention is to obviate the above-mentioned drawbacks.

More specifically, an object of the present invention is to provide an enhanced bending machine of a manually-operated or electrically-operated three-shaft type, all three shafts being driving, and such as to allow to permanently have a constant pressure on the pipe or profile during the bending step without any slippages thereof.

A further object of the present invention is to provide a bending machine that allows an easy adjustment of the position of the third shaft in order to make it permanently driver in any adjustment positions without causing variations in the pressure exerted onto the pipe or profile to be bent.

A further object of the present invention is to provide a three-driving-shafts bending machine featuring reduced space occupation and such as to allow an easy transportation thereof.

A further object of the present invention is to put at users' disposal an enhanced, manually-operated or electrically-operated bending machine suitable for providing high strength and reliability over time and also such as to be implemented in an easy and cost-effective manner.

These objects and others are achieved by the invention that has the characteristics according to claim <NUM>.

According to the invention, an enhanced bending machine is provided suitable for performing bending operations in accordance with well determined forms and/or patterns for a tubular element or profile, comprising a framework which supports and accommodates the working members suitable for bending a pipe or profile, driving and moving members for driving and moving said working members, and adjustment members for adjusting the working members, the working members comprising three operating rollers or pulleys supported by their respective shafts, one shaft being movable, hence capable of getting closer to/moving away from the fixed-position shafts, the bending machine being characterized in that all three output shafts supporting the operating rollers or pulleys are drivers by way of the same driving member.

Advantageous embodiments of the invention are apparent from the dependent claims.

The constructional and functional characteristics of the enhanced manually-operated or electrically-operated bending machine according to the invention can be better understood from the following detailed description, wherein reference is made to the attached drawings, which illustrate one embodiment given for explanatory, non-limitative purposes only, and wherein:.

With reference to the mentioned figures, an enhanced bending machine according to the present invention, indicated by the reference numeral <NUM> as a whole, comprises a framework <NUM>, which supports and accommodates the working members suitable for bending a tubular element or profile <NUM>, driving and moving members for driving and moving said working members, and adjustment members for adjusting said working members.

The working members comprise three operating rollers or pulleys, namely one movable roller <NUM> and two fixed rollers <NUM>' and <NUM>'', arranged in a triangle or delta "Δ" configuration, stabilized externally to the framework <NUM>, by way of a key connection, by interference, or another known mode, on their respective output shafts <NUM>, <NUM>', and <NUM>'', of which the output shaft <NUM> is mounted on the framework <NUM> so as to be movable and be capable of getting closer to/moving away from the output shafts <NUM>' and <NUM>'' which, on the contrary, are mounted fixed with respect to the framework, said shafts also having axes of rotation parallel to each other.

The operating rollers or pulleys <NUM>, <NUM>', and <NUM>'' are each provided with a circumferentially developed groove or race <NUM>, the shape of which corresponds to the diameter and/or geometry of the tubular element or profile to be bent.

The output shaft <NUM> is movable, hence capable of getting closer to/moving away from the output shafts <NUM>' and <NUM>'' by way of the working member adjustment means, said adjusting means comprising a guide <NUM> slidable with respect to the framework <NUM>.

On the framework <NUM>, externally thereto and on the same side with respect to which the operating rollers or pulleys are arranged, there is stabilized a pair of opposing side rollers <NUM> spaced away from each other in such a way that the operating rollers or pulleys are positioned in the region interposed between said side rollers.

Said side rollers <NUM> feature an axis of rotation perpendicular to the axis of rotation of the operating rollers or pulleys and are rotationally arranged idle with respect to the support elements <NUM>, whose inclination in a plane perpendicular to the axes of rotation of the operating rollers or pulleys can be adjusted by way of an adjustment ring nut <NUM>, which each individual support element is provided with.

Internally to the framework <NUM> there is arranged a rotatably supported, worm-toothed shaft <NUM>, the axis of rotation of which is perpendicular to that of the shafts of the operating rollers or pulleys by way of bearings <NUM> or equivalently known rotational support elements.

The function of said worm-toothed shaft <NUM> is, as better described below, to allow for a simultaneous rotational driving of the operating rollers or pulleys, namely the movable one <NUM> and the fixed ones <NUM>' and <NUM>'', so as to bend tubular elements or profiles.

The movement of the guide <NUM> and, consequently, of the output shaft <NUM> which supports the operating roller or pulley <NUM>, i.e. the movable roller, with respect to the fixed rollers <NUM>' and <NUM>'' is performed manually by way of an adjustment knob or handwheel <NUM> (an adjustment vernier) which allows for an accurate and micrometric adjustment (along a graduated scale <NUM>') of the position of the guide <NUM> between a maximum separation position with respect to the fixed rollers or pulleys <NUM>' and <NUM>'' (position A) and a minimum separation position from the mentioned rollers (position B) so as to define a displacement indicated by "X" in <FIG>.

The rotation of the operating roller or pulley <NUM> takes place by way of a toothed wheel <NUM> which meshes the worm-toothed shaft <NUM> (in any positions determined by adjusting the guide <NUM>), said toothed wheel being secured to the movable shaft <NUM>; the same toothed wheel <NUM> forces the movable output shaft <NUM> to rotate with respect to its own axis as described below in details.

The rotation of the output shafts <NUM>' and <NUM>'', which are fixed with respect to their own axes and, consequently, of the operating rollers or pulleys <NUM>' and <NUM>'' takes place by way of a transmission <NUM>, which comprises a transmission shaft <NUM>, a first toothed transmission wheel <NUM> put in said transmission shaft and mesh-coupled with the worm-toothed shaft <NUM>, a second toothed transmission wheel <NUM> which is coupled with a first gear-roller <NUM> and with a second gear-roller <NUM> secured onto the fixed output shaft <NUM>' and output shaft <NUM>'' respectively.

The driving of the transmission <NUM> and, consequently, the rotation of the output shafts <NUM>' and <NUM>'' takes place by way of a further handwheel or handle <NUM> arranged on the opposite side with respect to the knob or handwheel <NUM> and secured to the worm-toothed shaft <NUM>.

The worm-toothed shaft <NUM> and the transmission <NUM> make up the member that drives the bending machine according to the invention which, owing to its own rotation, allows to simultaneously and synchronously move the movable output shaft <NUM> counterclockwise, in a direct manner, and the fixed shafts <NUM>' and <NUM>'' clockwise, in an indirect manner, by way of the transmission <NUM>.

The operation of the enhanced bending machine, as described in details above with respect to its constructional characteristics, is described below.

A tubular element <NUM> to be bent is loaded onto the bending machine and arranged between the operating rollers or pulleys <NUM>, <NUM>', and <NUM>'', as shown in <FIG>, the outer surface of said tubular element coupling with the grooves or races <NUM> of the mentioned operating rollers or pulleys and is also being in contact with the surfaces of the opposed side rollers <NUM>.

The position of the fixed operating roller or pulley <NUM> is manually adjusted by an operator by way of the guide <NUM>, by acting on the knob or handwheel <NUM> which, by rotating according to the direction of the arrow "Y" in <FIG>, causes a translational movement of the guide <NUM> according to the direction "X" and, consequently, the movement of the output shaft <NUM> which the operating roller or pulley <NUM> is put in; in this way, the operating roller or pulley <NUM> exerts a pressure onto the tubular element <NUM>.

At this point the operator rotates the further handwheel <NUM> according to the direction indicated by the arrow "P" in <FIG> and in <FIG> to forcedly rotate the worm-toothed shaft <NUM> with respect to its own longitudinal axis, said rotation determining a rotation of the toothed wheel <NUM> put in the movable output shaft <NUM> (a rotation according to the direction indicated by the arrow "K" in <FIG>) and meshing the worm-toothed shaft <NUM>, as well as a rotation of the transmission <NUM> and, more specifically, a rotation of the first toothed transmission wheel <NUM>, which meshes the worm-toothed shaft <NUM> and, by rotating, drives into rotation the transmission shaft <NUM> which supports the second toothed transmission wheel <NUM> which, being mesh-coupled with the first gear-roller <NUM> and with the second gear-roller <NUM>, drives into rotation the fixed output shafts <NUM>' and <NUM>'' and, consequently, the operating rollers or pulleys <NUM>' and <NUM>'' according to the directions indicated by the arrows "M" and "M'" in <FIG>, respectively.

The tubular element <NUM> is bent by making it slide between the operating rollers or pulleys by increasing or decreasing the distance of the movable operating roller or pulley <NUM> with respect to the fixed rollers or pulleys <NUM>' and <NUM>'' between position A and position B; as the guide <NUM> moves from position A to position B, the distance between the movable roller or pulley <NUM> and the fixed rollers or pulleys <NUM>' and <NUM>'' decreases and, in this way, the bending radius to be given to the tubular element becomes smaller.

The operator will bend a tubular element through a number of successive passages by varying each time the value for the displacement "X", i.e. by varying the position of the movable shaft <NUM> which supports the movable roller or pulley <NUM> with respect to the shafts <NUM>' and <NUM>'' by acting on the adjustment knob or handwheel <NUM>.

The enhanced bending machine as described above with reference to one manual operation embodiment can also be implemented in an electrical operation mode, which comprises an electric driving suitable for rotationally driving the worm-toothed shaft <NUM> which drives all three output shafts <NUM>, <NUM>', and <NUM>'' into rotation.

The advantages achievable with an enhanced bending machine according to the invention are apparent from the foregoing. An enhanced bending machine according to the present invention, of a three-shaft manually-operated or electrically-operated type, has all three shafts, drivers and is such as to allow to permanently have a constant pressure on the tubular element or profile during the bending step, while preventing it from slipping.

Further advantageous is the fact that the bending machine according to the invention, having all three shafts drivers, one of which in position-adjustable and driver in any positions, makes it possible to realize smaller bending radii, the capacity or characteristic of the profile or tubular element being equal, as compared to a three-shaft bending machines of a traditional type.

A further advantage is in that an enhanced bending machine according to the invention, wherein there are three driving shafts and the third shaft is simultaneously driver and movable, hence capable of getting closer to/moving away from the remaining two shafts, makes it possible to exert a pressure onto the tubular element in the bending step while preventing the latter from slipping and, consequently, residual deformations present in the tubular element during the bending step will be minor and reduced.

Further advantageous is the fact that a bending machine structured as described above makes it possible to perform bending operations on a tubular element while preventing oscillations from occurring in the tubular element itself in correspondence with its terminal part not held between the operating rollers or pulleys.

A further advantage is in that the use of a worm screw makes it possible to have a bending machine featuring reduced space occupation and also easy to transport.

Claim 1:
An enhanced bending machine (<NUM>) suitable for performing bending operations according to determined forms and/or patterns for a tubular element or profile (<NUM>), comprising a framework (<NUM>) which supports and accommodates working members suitable for bending a tubular element or profile (<NUM>), driving and moving members for driving and moving said working members, and adjustment members for adjusting the working members, the working members comprising three operating rollers or pulleys (<NUM>, <NUM>', <NUM>'') supported by their respective output shafts (<NUM>, <NUM>', <NUM>''), one output shaft (<NUM>) being movable hence capable of getting closer to/moving away from the output shafts (<NUM>', <NUM>'') whose position is fixed by means of adjustment members which comprises a guide (<NUM>) supporting said output shaft (<NUM>) and slidable with respect to the framework (<NUM>), the bending machine being characterized in that all three output shafts (<NUM>, <NUM>', <NUM>'') supporting the operating rollers or pulleys (<NUM>, <NUM>', <NUM>'') are drivers by way of the same driving member that comprises a worm-toothed shaft (<NUM>) arranged internally to the framework (<NUM>) and rotatably supported, the axis of rotation being perpendicular to that of the output shafts (<NUM>, <NUM>', <NUM>''), the rotational driving of the movable output shaft (<NUM>) being performed by way of a toothed wheel (<NUM>), which meshes said worm-toothed shaft (<NUM>) and which is secured to the movable shaft (<NUM>) and with said toothed wheel (<NUM>) which forces the movable output shaft (<NUM>) to rotate with respect to its own axis, and the rotational driving of the fixed output shafts (<NUM>', <NUM>'') being performed by way of a transmission (<NUM>), which receives motion from the same worm-toothed shaft (<NUM>).