[0001] This patent application concerns an automatic window shutter stop.
[0002] It is common knowledge that window shutter stops which are fixed to the external
walls of the building and which automatically catch the lower edge of the window shutter
when this is opened in full, have for years existed on the market. These window shutter
stops are in fact fitted with a "U" shaped bracket with curved elements turned upwards
which is pivoted, with respect to a horizontal pin, to a support square fixed to the
wall by means of a sturdy screw; it is worth mentioning that the bracket in question
is box-shaped thus permitting the same to house and conceal the square which allows
the same to be fixed to the wall.
[0003] Before the "U" shaped bracket catches the window shutter, the same is in fact slanted
forwards and downwards; in this way the rear edge of a shutter which is opened passes
over the front curved element of the bracket without interfering with the same.
[0004] Said interference however occurs immediately afterwards with the rear curved element
of the same bracket.
[0005] This interference causes the bracket to oscillate behind with respect to its horizontal
pivoting pin, fixed on the support square; in this way as its rear curved element
moves backwards the front curved element lifts.
[0006] This oscillation stops as soon as the bracket is in a perfectly horizontal position,
against the upper surface of the relevant support square fixed to the wall; it is
evident that when the bracket is in this horizontal position, the lower edge of the
window shutter is held and locked between both curved elements of the bracket.
[0007] In this respect it should be noted that the above bracket can automatically and stably
lock in this horizontal position; this feature is in fact indispensable to ensure
the stable locking of the window shutter in fully open position.
[0008] If in fact the bracket were to oscillate freely downwards, the edge of the window
shutter would be released from the obstacle created by the front curved element and
the window shutter would thus be free to close, even simply by the force of the wind.
[0009] The automatic locking of this bracket above the relevant support square occurs when
an upward turned tooth, fitted at the front end of the square, is hooked by the hooked
end of a ratchet gear opposite the same.
[0010] The ratchet gear is in fact housed in the body of the "U" shaped bracket and is pivoted
with respect to a horizontal pin positioned slightly forwards and parallel to the
above pin which ensures pivoting between the "U" shaped bracket and square. In particular,
hooking between the tooth of the square and said ratchet gear occurs at the end of
the backward oscillation of the "U" shaped bracket when the ratchet gear, during its
upward rise - together with the "U" shaped bracket - passes over and securely hooks
the tooth of the support square.
[0011] It should be noted moreover that the thrust from the edge of the window shutter on
the rear curved element of the "U" shaped bracket should be rather strong since attachment
of the ratchet gear and the tooth of the square is opposed by an antagonist spring
fitted on the ratchet gear.
[0012] It is thus evident that in order to release the window shutter from a bracket of
this type it is necessary firstly to release the stable attachment between the "U"
shaped bracket and the square which supports it; only in this way can the bracket
in fact be returned to its slanted position, namely so that its front curved element
does not prevent the window shutter from closing.
[0013] This operation can in fact be carried out by releasing the ratchet gear from the
tooth of the support square; this may be done by means of a trigger fitted to the
ratchet gear and which projects from the front section of the "U" shaped bracket immediately
under the front curved element.
[0014] In particular, by pushing this trigger downwards, it is possible, by overcoming the
antagonistic force of the spring, to rotate the ratchet gear towards the front of
the bracket, and consequently free the same from the tooth at the end of the hooking
square to the wall.
[0015] Although this type of window shutter stop is commonly used and practical - it does
have the disadvantage of having a rather fragile structure.
[0016] More precisely, it has been ascertained, above all after fairly prolonged use of
these stops, that the hooked end breaks off the ratchet gear fitted in the "U" shaped
bracket, namely the one that directly ensures the attachment with the tooth provided
on the front of the body of the supporting square.
[0017] The reason for this is the considerable bending strain that this hooked element of
the ratchet gear undergoes, above all in certain conditions, as for example in the
case of strong wind. It is evident in fact that when the window shutter is locked
between the curved elements of the window shutter in question, the only thing that
prevents oscillation towards the bottom of the "U" shaped bracket, and thus release
of the window shutter, is the attachment between the hooked end of the ratchet gear
and the tooth of the support square.
[0018] It is quite clear therefore that the hooked end of the ratchet gear can break when
the window shutter is banged shut against the front curved element of the "U" shaped
bracket, as occurs in the case of violent storms or strong wind.
[0019] It is also evident that when the ratchet gear of the "U" shaped bracket breaks the
mechanism is seriously damaged in that it irreparably compromises the function of
the window shutter stop, which will necessarily have to be replaced with a new part.
[0020] The purpose of this invention is to realise a window shutter stop having a similar
basic structure to that of the above window shutter stops, without the risk however
that the ratchet gear in the "U" shaped bracket, breaks.
[0021] In order to achieve this, the locking system between the box-shaped bracket and the
relevant square has been re-designed, eliminating the reciprocally stopping elements
subject to bending strain, but hooking the elements subjected to more supportable
compression strain.
[0022] Thanks to this solution it is evident that this new fixing system is much sturdier
than traditional window shutter stops and consequently able to sustain major strain
transmitted by the window shutter.
[0023] For major clarity the description of the invention continues with reference to the
enclosed drawing which is intended for purposes of illustration and not in a limiting
sense, whereby figures 1, 2 and 3 illustrate by means of the same number of side views
a window shutter stop of the type according to the invention whose oscillating bracket
is cross-sectioned with a longitudinal median plane.
[0024] The three figures show the device in the three operating positions, namely in resting
position before the edge of the window shutter has been caught and locked (figure
1), in the position during locking of the window shutter (figure 2) and in the position
immediately after the stopping means between the bracket and the support square (figure
3) have been released. With reference to the enclosed figures, the window shutter
stop according to the invention generally consists of an oscillating box-shaped bracket
(1) provided with two curved elements (1a and 1b) joined by a horizontal wall (1c)
and pivoted, with respect to a horizontal transverse pin (2), to a shaped square (3)
provided at the rear end with a screw (4) used to fix the same to the wall.
[0025] It should also be noted that the front end of the square (3), housed in the box-shaped
square (1) terminates at the top with a short nib (5) having a rectilinear upper wall
(5a) and a lower sloping wall (5b).
[0026] It being provided that in the box-shaped bracket (1) an "L" shaped lever (7) having
vertical wing (7a) turned upwards and subject to the thrust of a spring (8) fitted
between said wing (7a) and a transverse section (1d) in the longitudinal wall (1c)
of the bracket (1), is pivoted with respect to a second transverse pin (6).
[0027] The end of the horizontal wing (7b) of this "L" shaped lever (7) being provided with
a trigger (9) projecting from the bracket (1 ) under the front curved element (1 b).
[0028] The end of the vertical wind (7a) of said lever (7) terminates with a transverse
pin (10) which hooks into a notch (11a) realised below a special small parallelepiped
block shaped slider (11).
[0029] This slider (11) being able to translate alternatively with respect to the longitudinal
axis of the bracket (1) according to the positions of the relevant operating lever
(7), while keeping parallel and in contact with the inner face of the longitudinal
wall (1c) of the bracket (1).
[0030] With particular reference to figure 1, when the bracket (1) is slanted forwards,
the lever (7) is entirely housed in the box-shaped bracket (1) so that the rear face
of the slider (11) fitted at its end abuts against the lower sloping wall (5b) of
the nib (5b) provided on the front of the supporting square (3). In particular, this
figure illustrates that the rotation of the bracket (1) stops when its nib (5) touches
against a counter-nib (1e) provided on the longitudinal wall (1c).
[0031] When, after it has been opened, the window shutter interferes with the rear curved
element (1a) of the bracket (1), the bracket (1) generally swings back tending therefore
to assume its operating position, as illustrated in figure 2.
[0032] During said backward oscillation and thanks to the thrust ensured by the interference
of the window shutter, the block (11) fitted at the top of the lever (7) moves back
briefly and passes over the nib (5) of the square (3) thanks to the thrust of the
spring (8), so that it positions itself exactly between the inner face of the longitudinal
wall (1c) of the bracket (1) and the upper rectilinear wall (5a) of the nib (5).
[0033] It is the very provision of said block (11) between bracket (1) and the square (3)
as a spacer, which is the feature that prevents the bracket (1) from rotating freely
downwards around its pivoting pin (2).
[0034] In other words, positioning the block (11) between the bracket (1) and the square
(3) performs the same function - on the basis of a totally different logic however
- which in traditional window shutters was performed by the attachment between the
ratchet gear housed in the box-shaped bracket and the upward facing tooth provided
at the front end of the supporting square.
[0035] By observing figure 2, it is evident that the thrust produced by the window shutter
on the front curved element (1 b) of the box-shaped bracket (1) simply squeezes the
slider (11) between the inner wall (1c) of the box-shaped bracket (1) and the nib
(5) of the support bracket (3).
[0036] It is evident therefore that the block (11) which undergoes compression, is not subject
to the risk of breakage due to bending.
[0037] With reference to figure 3, it is evident that in order to release the bracket (1)
and the support square (3) it is necessary to lower the trigger (9), overcoming the
force of the spring (8) that opposes the vertical wing (7a) of the "L" shaped lever
(7). This operation in fact makes the slider (11) slide towards the front of the bracket
(1) and therefore prevents its lower face from interfering with the rectilinear wall
(5a) of the nib (5) of the square (3).
[0038] The number (12) refers to a piston having horizontal axis with relevant spring (12a)
provided at the top of the rear curved element (1a) of bracket (1) which cushions
the impact of the edge of the window shutter, while the number (13) refers to a cap
which can be fitted into different positions on the top of the front curved element
(1b) in order to regulate the centre to centre distance between the two curved elements
of the device according to the invention.