OBJECT OF THE INVENTION
[0001] The invention proposed herein consists of a telescopic socket for the shafts of roller-type
blinds, although other applications, such as Venetian or roll-up blinds and other
window accessories, are not discarded.
[0002] The socket consists of three parts, a graduated external tubular part, another part
that is also graduated tubular part that slides inside the aforementioned part, passing
through both ends and held inside the former by means of an intermediate spring, such
that the anterior part is left free to facilitate assembly either of the socket or
of the socket and of the bearing included alternately to the pin, at the outer end
of the innermost part.
BACKGROUND TO THE INVENTION
[0003] Normally the shafts of roller blinds have to be cut to lengths shorter than the lengths
of their respective brackets and, since the space occupied by the rolled-up blind
is not usually calculated to the nearest millimetre, when the winding case is built,
above all in the case of brickwork splays, it is almost essential to have the blind
unrolled and dismantled to move or put its shaft in place.
[0004] As a result, blind fitters tend to leave the shafts short with regard to their housing
to avoid having to use the trial and error method, and so insert it the first time,
slightly sloping and forming an angle with the horizontal plane.
[0005] In the long run this causes the rolled blind to fall unexpectedly onto the base of
its case whenever the shaft moves sideways, however slightly.
[0006] The telescopic systems used to extend the blind shaft make it easier to put the aforementioned
shaft in place, snug at each end, and yet also make it easy to assemble and dismantle.
[0007] Other systems are equipped with two springs housed at the opposite ends of the arm
of a symmetric, hollow arm, sealed at one of the ends and inserted at the other inside
a similar cross and formed by four orthogonal, triangular cross-section flats, inscribed
as blades inside a cylinder, the curved outer face of each triangle coinciding with
a sector of the circle in which they are inscribed.
[0008] The above notwithstanding, it has been seen that the origin of the problem arises
when the blind is first assembled, such that it is when the fitter forcibly inserts
the bearing in its housing at the end of the inner part of the socket that the spring
deviation problems arise. These problems sometimes make it necessary to completely
dismantle the socket and, at any rate, they damage the bearings and/or housings, due
to the excessive force that must be used to offset additionally the compression of
the shaft in its housing.
DESCRIPTION OF THE INVENTION
[0009] The invention described herein is a telescopic socket for blind shafts, in three
single parts.
[0010] The first part is an outer tubular part, provided with a flange that acts as a stop
for the inserted end of the blind shaft and that is of the opposite shape to the inner
body of the latter, preferably hexagonally-shaped.
[0011] Inside, and at the opposite end to the flange, the part is closed transversally,
by way of a graduated riser that drastically reduces its cross-section, albeit maintaining
the same geometrical shape, which is connected to a coaxial extension that is much
shorter than the body of this outer part and that juts out on both sides of the riser,
with a square cross-section and slightly bevelled vertices. Also, two of the opposite
faces are provided with two end notches.
[0012] The other, innermost part is also tubular and graduated, starting with a circular
cross-section in the area with the largest cross-section and changing to a square
cross-section at the other end. It slides into the free end of the anterior part,
passing through both ends of the former, and is attached on the inside to the aforementioned
inner graduated riser of the latter by a spring that is pre-assembled in the second
part and that circumscribes the part of the reduced step of the latter.
[0013] The end of the inner sliding part that has largest surface area is circular on the
outside, and has a tubular cylindrical housing, its inner generatrices having a large
number of projections, to a conventionally built stop or transverse base that houses
the socket bearing.
[0014] This tubular element of the end extends beyond this bearing housing, and is graduated
at the end to stop the aforementioned spring.
[0015] Inside, the spring is guided and held in place, to prevent any sinusoidal bending
when it moves, by the posterior housing of this bearing housing, by way of a graduated
projection and much longer, of this inner sliding part, with a square cross-section
as described.
[0016] This sliding part is also characterized by having a notch at the free ends of its
edges, thus generating extreme elastic media of the extension that supports the spring,
that fasten the inner part on the outside, formed by diametrically opposite, elastically-retracting
catches that fit in the opposite-shaped notches of the outer hexagonal extension.
[0017] To insert the bearing in its housing, it is only necessary to place the socket in
an upright position, supported on the respective bases of both the outer and sliding
part, insert the bearing in its housing and press it until it is fully inserted. The
stress is borne by the dual extension of the inner and outer parts, just the opposite
to what happens when conventional sockets are assembled.
[0018] In addition to this possibility, throughout this period the spring does not have
to bear the pressure used to insert the bearing, normally involving blows with a soft
mallet, so it does not deform, move out of the lower housing or move sideways, meaning
that the socket must remain incorrectly placed throughout the time that it is used,
or forcing the worker to dismantle the parts and recommence the operation.
DESCRIPTION OF THE DRAWINGS
[0019] A set of drawings have been enclosed with this descriptive report, of which they
form an integral part, in order to supplement this description and make it easier
to understand the characteristics of the invention. These drawings, which are provided
for the purposes of illustration and are by no means of a limiting nature, show the
following:
Figure 1 is a cross-section of the socket described in this invention, showing how
the parts fit together and the other improvements described, for the two alternatives,
with a pin and for a bearing.
Figure 2 shows a front view and cross-section of the outer part of the socket described
in this invention.
Figure 3 shows the opposite front views and a cross-section of the inner part of the
socket described in this invention, showing the catches that hold both parts in place,
and the other improvements described, for the two alternatives, with a pin and for
a bearing.
PREFERABLE EMBODIMENT OF THE INVENTION
[0020] In view of the description given above, this invention refers to a telescopic socket
for blind shafts, in three single parts, the first being an outer tubular part (1),
with a flange (2) that acts as a stop for the end of the blind shaft, preferably hexagonally-shaped
and with a sliding mortise (2') which internally closes in a riser (3), which extends
into an coaxial extension (4) that crosses the riser (3) and that has a rectangular
cross-section with bevelled vertices, while the other tubular, circular cross-sectioned
inner passing part (5) changes gradually (6) into a square cross-section and slides
into the free end of the anterior and is equipped, alternatively, with a pin (7) that
acts as the outer support of the blind, or else a body (7') with projections that
houses the socket bearing.
[0021] This body (7') extends beyond the base (8) of the bearing support, in a mortise (9)
that is graduated (11) to act as the spring stop (10). It also has catches at its
notched end (6) that fit in the opposite-facing notches (12) of the tubular section
(1).
[0022] This doubly self-sliding construction of parts (1) and (5) of the socket also make
it possible to move one on top of the other when the blind is being handled, without
the weight of the blind causing the warping that normally occurs with conventional
blinds.
[0023] A fuller description is not given because it is understood that any expert in this
field will have enough information to understand the scope of the invention and its
derived advantages, and to reproduce it.
[0024] It is understood that, as long as the essential nature of the invention is not changed,
both the materials and the shape, size and layout of the parts are liable to change
within the same characterization.
[0025] The terms used in the description and the sense thereof should always be considered
to be of a non-limiting nature.
1. Telescopic socket for blind shafts, with three parts, two, tubular parts plus a spring,
with an outer part (1), with a conventional flange (2) acting as a stop and a sliding
mortise (2'), essentially characterized in that part (1) ends in a riser (3), which
extends into an coaxial extension (4) having a rectangular cross-section, that incorporates
inner, inside sliding part (5), that is graduated (6) into a square cross-section
and slides into the free end of part (1) in a doubly self-sliding antiwarp construction
of parts (1) and (5) of the socket.
2. Telescopic socket for blind shafts, as per the previous claim, characterized in that
the body (7') of part (5) extends the bearing support base (8), in a mortise (9) that
is graduated (11) to act as the spring stop (10) and that also has catches at its
notched end (6) that slot into the opposite notches (12) of the tubular section (1).