OBJECT OF THE INVENTION
[0001] The present invention relates to a roller such as those used in spinning lathes,
in which a chuck presses a disc-shaped metal sheet against a rotary mold and on which
said sheet acts at least one roller mounted on a carriage with a programmed automated
motion, so that said roller deforms the sheet against the rotary mold so that it adopts
the shape of the latter.
[0002] The object of the invention is to provide a roller with great structural simplicity
and simple assembly, with the ensuing benefits in the costs of fabrication and assembly
and disassembly of the rollers.
BACKGROUND OF THE INVENTION
[0003] In spinning lathes a power unit supplies a rotational motion to a mold shaped as
a solid of revolution, so that on a single lathe may be implanted molds with different
generatrices, depending on the desired shape of the sheet after spinning.
[0004] The sheet is initially flat and circular, and rests on its centre and axially on
the mold, to which it is secured by a chuck which allows it to rotate freely when
driven by the mold. On said sheet acts a roller which is rotationally mounted on a
roller-bearing carriage, so that the roller follows the path of the mold generatrix
with automated motions which correspond to a control program of said carriage.
[0005] Conventional rollers consist of two parts, the roller itself and a cover which is
attached to it by bolts, so that these elements define an axial housing for a pair
of bearings and the corresponding spacer placed between them. These bearings are obviously
meant to allow a free rotation of the rollers about their axis, with the cover closing
the roller housing after such mechanisms are installed inside it.
[0006] The complexity of this structure implies large machining costs, on one hand to obtain
the two basic parts of the roller and in addition to drill said parts and thread one
of them to allow the implementation of the attachment bolts, to which must be added
the complexity of the assembly which results from this large number of components.
DESCRIPTION OF THE INVENTION
[0007] The roller for spinning lathes disclosed solves the above drawbacks in a fully satisfactory
manner, providing a solution with a simple structure and assembly, with the ensuing
reduction in costs.
[0008] For this purpose and more specifically, the roller consists of a single part, not
requiring a cover nor any additional accessories for mounting the bearings, which
is the only machined part of the assembly and which in the inevitable axial orifice
for coupling to the shaft incorporates an intermediate narrowing which acts as a spacer
for the conventional bearings, so that these are mounted on opposite sides of the
roller, with the outer bearing axially retained by the conventional flange at the
end of the aforementioned shaft, while the other bearing is also retained axially
against the common spacer by a simple washer which remains in working position when
said shaft is coupled and attached to the corresponding roller-bearing carriage.
[0009] In this way the conventional cover of the roller can be eliminated, as well as the
drilled orifices required in these for installing them, allowing in addition a much
simpler and faster assembly.
DESCRIPTION OF THE DRAWINGS
[0010] The characteristics of the present invention will be better understood in view of
the accompanying drawings of a preferred embodiment of the invention, where in a non-limiting
manner and for purposes of illustration only the following is shown:
Figure 1 shows a schematic representation of a spinning lathe with the roller object
of the present invention.
Figure 2 shows a side elevation view and diametric section of said roller.
PREFERRED EMBODIMENT OF THE INVENTION
[0011] Figure 1 shows a schematic representation of a conventional spinning lathe which,
as is conventional, comprises a rotary mold (1) driven by a power unit (2), which
rotary mold in this case has a cambered hemispherical configuration but which may
adopt any other shape depending on that intended for the sheet (3) to be spun, and
which mold (1) is placed axially opposite a chick (4) which is aided by the corresponding
driving mechanism (5), so that said chuck (4) can push the sheet (3) against mold
(1) on its centre, keeping it perfectly held in place while the roller (6) acts, which
mounted on a roller-bearing carriage (7) follows the generatrix line of the mold (1),
for which purpose said roller-bearing carriage is provided with automated motion means
and is duly programmed.
[0012] In accordance now with the invention, said roller (6) consists of a roller (6) itself,
in a single part, with the classical rounded, operational perimetral edge (8) and
with the also classical axial orifice (9) for passage of shaft (10) for coupling to
the carriage (7), with a pair of bearings (11-11') interposed; also in accordance
with the invention said roller (6) itself, at its mid area of its axial orifice (9),
incorporates a narrowing (12), that is, an inner annular ribbing which acts as a spacer
for bearings (11-11'), as shown clearly in figure 2.
[0013] The outer bearing (11) is retained against spacer (12) by flange (13) at the free
end of shaft (10), while the internal bearing (11') is in turn retained axially against
spacer (12) by a washer (14), which when the roller assembly is mounted on carriage
(7) presses sideways on the arm (15) of said carriage, when the latter is finally
secured by bolt (16).
1. Roller for spinning lathes, of the type in which the roller itself is provided with
an axial orifice for passage, with an interposed pair of bearings, of the shaft by
which said roller is rotationally mounted on the roller-bearing carriage, characterised in that the roller itself (6), in the mid area of its axial orifice (9), incorporates a narrowing
which defines an annular ribbing (12) which acts as a stop spacer for the pair of
bearings (11-11'), so that said bearings are mounted on the roller itself by its opposite
sides, with the outer bearing (11) axially retained by the classical flange (13) of
the roller shaft (13), while the inner bearing (11') is in turn retained axially against
the spacer (12) by a washer (14) which rests against the corresponding lateral face
of the arm (15) of the roller-bearing carriage (7) when the shaft (10) of the roller
is finally secured to said carriage.