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(11) | EP 1 748 147 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Safety brake for gates |
| (57) This invention relates to a safety brake for gates, especially for single-piece gates
or doors or gates or doors based on hinged or overlaid panels, which are suspended
from at least one cable and have a transverse shaft ending in a pair of wheels (2)
for their sliding in U-shaped vertical side rails (1). The shaft (3) of each wheel
(2) incorporates a catch (5) provided with a peripheral groove (8) for the passage
of the suspension cable (9), such that said cable, and due to the effect of the weight
of the door, tends to locate the catch (5) in the inoperative position, whereas a
spring (11) assembled between the shaft (3) and the catch (5) tends to make the latter
pivot towards the locking position, becoming operative when the cable breaks.
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OBJECT OF THE INVENTION
[0001] The present invention relates to a safety brake especially provided for being used in gates or doors suspended from at least one cable, such as doors made up of two panels hinged according to a horizontal shaft.
[0002] The object of the invention is to prevent the uncontrolled falling of the door in the event that the cable should break, with the unforeseeable consequences this may imply.
[0003] More specifically, achieving a structurally simple and functionally effective braking device that does not negatively affect the door opening ability is object of the invention.
BACKGROUND OF THE INVENTION
[0004] In the previously mentioned gates and doors that consist of either a single pivoting piece or a vertically dropping piece (guillotine) while at the same time raising/lowering, or two hinged folding/unfolding pieces, a pair of U-shaped vertical side rails or guides with opposite openings are always used in which respective wheels assembled on the ends of a transverse shaft associated to the door, which door hangs through said axle, generally from two side cables, the winding or unwinding of which from an upper shaft causes the door to raise or lower.
[0005] Obviously, such cables further act as door support means, such that the breaking thereof implies the mentioned falling or dropping of the gate or door.
[0006] Braking devices are known for preventing this problem but such braking devices have different load drive shafts, the drive shaft always being in the upper part and eliminating from the elevation system as a whole an upper cavity generally comprised between 5 and 10 cm, preventing complete door opening which is occasionally a significant problem especially when the height of the cavity for the passage needed through it is minimal.
[0007] These braking mechanisms are furthermore structurally complex and therefore expensive from both the manufacturing costs point of view and from the assembly and maintenance point of view.
DESCRIPTION OF THE INVENTION
[0008] The brake proposed by the invention resolves in a fully satisfactory manner the drawbacks previously set forth in the different aspects discussed.
[0009] To that end and more specifically, the features of said brake are focused on the incorporation on each end of the door pivot or fold shaft next to the corresponding wheels and within the rails in which the latter slide, respective catches each of which is provided with a pair of diametrically opposing arms ending in notches and the ends of which are spaced at a magnitude exceeding the width of the rail, each catch having a peripheral groove through which the suspension cable of the door passes such that said cable, and due to the effect of the weight of the door, tends to make the catch pivot towards a position that is physically independent of the rail, whereas a spring arranged between the catch and said pivot shaft in turn tends to make said catch pivot towards the locking position against the rail, said spring usually being inoperative and becoming active when the cable breaks.
[0010] This spring must logically be appropriately over-tensioned so as to prevent the loss of load occurring due to the rotation of the shaft during the pivoting of the door from making it inoperative.
[0011] To facilitate the assembly of the brake, and generally the assembly of the door, it has been foreseen that said braking mechanism incorporates a safety arm fixed by means of a screw keeping the catch inoperative, said arm being eliminated or released once the cable of the catch has been coupled and the door is suspended therefrom.
[0012] As can be deduced from the foregoing, the braking device proposed by the invention does not take up any space whatsoever that may negatively affect the door opening degree, which can be 100%.
[0013] Its functionality in habitual door use is optimal and the risk of deterioration of its components virtually zero.
[0014] Its structural simplicity and assembly simplicity mean lower costs in comparison to conventional braking systems, which may cost over 50% more.
DESCRIPTION OF THE DRAWINGS
[0015] To complement the description that is being made and for the purpose of aiding to better understand the features of the invention according to a preferred embodiment thereof, a set of drawings is attached as an integral part of said description which, with an illustrative and non-limiting character, show the following:
Figure 1 shows a plan view of a safety brake carried out according to the object of the present invention, duly coupled to a door or gate suspended from cables, in the operative locking position for said brake.
Figure 2 shows a side elevational view of the detail of the previous figure in the same locking position.
Finally, Figure 3 shows a depiction similar to that of Figure 2, but in which the braking device is in a normal door operation position, i.e. when the door is suspended from the corresponding cable or pair of cables and the brake is inactive.
PREFERRED EMBODIMENT OF THE INVENTION
[0016] In the mentioned figures, particularly in Figure 1, it can be seen how the safety brake proposed by the invention is applicable to doors or gates in which there are two U-shaped vertical rails (1) in opposite positions in correspondence with the sides of the door, rails (1) in which respective wheels (2) slide that are normally arranged with a freely-rotating assembly on the ends of the pivot shaft for the panels forming the door.
[0017] According to the invention, each wheel (2) is assembled on an auxiliary shaft (3) incorporating on its inner end a threaded blind hole (4) through which it is joined to the also threaded end of the mentioned pivot shaft of the door; assembled on this auxiliary shaft (3) there is a catch (5) provided with a pair of diametrically opposing arms (6-6'), the free notched ends (7) of which are spaced at a magnitude exceeding the width of the rail (1), such that said arms are intended for locking in such rail (1), specifically in the side branches (1') thereof when the brake is activated, as will be seen below.
[0018] The catch (5) incorporates a peripheral groove (8) through which the door suspension cable (9) passes, such that under normal conditions and due to the weight of the door, said cable tends to force the catch (5) to adopt the inoperative position shown in Figure 3, in which the ends (7) of its arms (6-6') are substantially spaced from the side branches (1') of the rail (1), and accordingly the door functions in a normal fashion, the wheels (2) sliding through the rails (1).
[0019] A helical spring (10) collaborates with the catch (5), which spring is provided with two end pins, one pin (11) being fixed to the catch (5) in a hole (12) existing in the latter, and the other pin (13) in turn being fixed in a hole existing in the door pivot shaft, not depicted in the drawings. This spring (10) to make the catch (5) pivot from the normal working position shown in Figure 3 to the brake or locking position shown in Figure 2 when the cable (9) breaks.
[0020] As a complement of the described structure a safety arm (15) is integrally joined by means of a screw (14) to the shaft (3) on which the catch (5) is assembled, which arm is able to lock the catch (5) in its inoperative position, as shown in Figure 3, canceling out the effect of the spring (10), which in turn quite considerably facilitates the assembly of the device, such that once the cable (9) has been placed in the groove (8) and the door suspended from the cable, the mentioned safety arm (15) can be decoupled from the catch (5), or it can even be removed.
1. A safety brake for gates, especially for single-piece gates or doors or gates or doors
based on two hinged or overlaid panels which are suspended from at least one cable
and have a transverse shaft ending in a pair of wheels for their sliding in U-shaped
vertical side rails, characterized in that the shaft of each wheel incorporates a catch provided with a peripheral groove for
the passage of the suspension cable, such that said cable, and due to the effect of
the weight of the door, tends to locate the catch in the inoperative position, whereas
a spring assembled between the shaft and the catch tends to make the latter pivot
towards the locking position, becoming operative when the cable breaks.
2. A safety brake for gates according to claim 1, characterized in that the shaft of the wheel is a small auxiliary shaft provided on its inner end with
a threaded blind hole for coupling of the also threaded end of the door pivot shaft,
assembling on said auxiliary shaft both the catch and the helical spring, which incorporates
end pins for the fixing to the catch and to the door pivot shaft, respectively.
3. A safety brake for gates according to the previous claims, characterized in that the catch incorporates a pair of diametrically opposing arms ending in notched ends
enhancing their grip on the side walls or branches of the rail, for which purpose
the spacing between the free ends of said arms is slightly greater than the spacing
between the side branches of the rail.
4. A safety brake for gates according to the previous claims, characterized in that the auxiliary shaft incorporates a safety arm removably assembled by means of a screw,
such that said arm keeps the catch inoperative during door assembly until the door
is suspended from the cable.