Bidirectional closing mechanism

Abstract

 The present invention relates to a bidirectional closing mechanism 6 for hinged members 1 comprising a rotational output 8, a shaft 10; an actuator connected to said shaft 10 for urging said shaft 10 in a first direction of rotation around a main axis of said shaft 10; a damper 12 coupled to said shaft, for damping rotation of said shaft with a substantially higher damping coefficient in said first direction of rotation than in an opposite second direction of rotation; and a transmission 9 between said output 8 and said shaft 10. This transmission 9 comprises a pinion 26 coupled to said shaft 10; a first gearwheel 27 directly engaged with said pinion 26; a second gearwheel 28 coupled with said pinion 26 over a reversing gear 29, and a toothed arc extending between said first gearwheel 27 and said second gearwheel 28, but not beyond both at the same time.

Description

[0001] The present invention relates to a bidirectional closing mechanism for hinged members.

[0002] Closing mechanisms for hinged members, such as doors, gates and windows, are well-known in the art. One such closing mechanism is illustrated in US Patent US 4,825,503. This closing mechanism comprises a rotational output, a shaft, an actuator connected to said shaft so as to urge said shaft in a first direction of rotation around a main axis of said shaft, and a rotation damper, also coupled to said shaft, with a substantially higher damping coefficient in said first direction of rotation than in an opposite second direction of rotation. The closing mechanism can thus return to an initial closed position a hinged member linked to said shaft which is opened away from said initial direction against said actuator. This prior art closing mechanism is reversible, so that it can be used for both clockwise and counter-clockwise opening hinged members by turning it around and using one or the other of the oppositely oriented first and second ends as an output.

[0003] This closing mechanism of the prior art does however present various drawbacks. In particular, adapting it to right- or left-hand-opening hinged members is complicated and far from foolproof. Because its hydraulic rotation damper is turned around with the rest of the rotation actuator, and because it presents joints at both ends, as well as a damping adjustment valve in fluid connection with a high-pressure side of the damper, this rotation actuator may be considerably prone to leakages, sensitive to temperature variations and therefore badly suited for outdoors use. Moreover, because the rotating piston of this hydraulic damper has a travel of less than 360°, the damper is directly coupled to the actuator output, without any multiplication stages. Since in this application it is important for the damper to be as compact and unobtrusive as possible, the area of the piston is necessarily limited. To achieve the required damping torques, comparatively high hydraulic pressures will thus be required. This will further increase the risk of leakages.

[0004] It is a first object of the present invention to provide a bidirectional closure mechanism which can be used in both right- and left-hand-opening hinged members, while retaining in both cases a higher damping in the closing direction than in the opening direction.

[0005] The bidirectional closing mechanism of the invention also comprises at least a rotational output, a shaft, an actuator connected to said shaft for urging said shaft in a first direction of rotation around a main axis of the shaft, and a damper, coupled to said shaft, for damping rotation of said shaft with a substantially higher damping coefficient in said first direction of rotation than in an opposite second direction of rotation. The closing mechanism of the invention achieves the abovementioned first object by also comprising a transmission between said shaft and said output, with a pinion coupled to said shaft, a first gearwheel directly engaged with said pinion, a second gearwheel coupled with said pinion over a reversing gear, and a toothed arc, coupled to said output, and extending between said first gearwheel and said second gearwheel, but not beyond both at the same time, so that, when it is moved in the direction of the first gearwheel, it turns said shaft, over said first gearwheel and pinion, in said second direction of rotation, whereas when it is moved in the direction of the second gearwheel, it turns said shaft, over said second gearwheel, reversing gear and pinion, in the same second direction of rotation. Thus the torque output of the closing mechanism over the toothed arc is reversed, without any adjustment or change to the closing mechanism.

[0006] It is a further object of the present invention to provide a multiplication between said output and said shaft. For this purpose, said toothed arc may have a larger nominal radius than said pinion, preferably at least twice as large, even more preferably at least three times as large. By "nominal radius" of a toothed gear it is understood the distance between its centre and the contact point of its teeth with those of another gear which it is in engagement with. In the arrangement of the invention, by having a toothed arc with a larger nominal radius than that of the pinion, a multiplication ratio in both directions is achieved that is equal to the ratio between the nominal radius of the toothed arc and that of the pinion.

[0007] It is a further object of the present invention to provide a particularly compact closing mechanism. Advantageously, said toothed arc presents an inner toothing. It can thus be arranged in a cap surrounding and preferably protecting the abovementioned gearing. This provides a particularly compact and reliable transmission.

[0008] It is a further object of the present invention to provide a particularly reliable closing mechanism. Advantageously, said actuator may be a resilient element, preferably in the form of a torsion spring, in particular a coil torsion spring. Nevertheless, according to the particular circumstances applied, alternative actuators, such as pneumatic, magnetic or electric actuators, could also be considered.

[0009] It is a further object of the present invention to provide a closing mechanism with an adjustable torque output. Advantageously, the closing mechanism according to the invention may thus comprise a mechanism for adjusting a preload of said actuating element. Even more advantageously, said preload adjusting mechanism may comprise a worm in self-locking engagement with a worm-wheel connected to said actuating element. This provides and maintains an easily adjusted preload of the actuating element.

[0010] It is a further object of the present invention to provide a closing mechanism with an efficient damper. Advantageously, said damper may thus be hydraulic. More advantageously, the damper may comprise a cylinder barrel enclosing a cylinder cavity with a longitudinal axis, a damper shaft rotatable with respect to said cylinder barrel substantially around said longitudinal axis, and a piston placed within said cylinder barrel so as to divide the cylinder cavity into a first side and a second side in restricted fluid communication with each other; and a one-way valve allowing fluid flow from said first side to said second side of the cylinder cavity. Said piston may then comprise at least one helical thread in engagement with a corresponding thread on either the cylinder barrel or the damper shaft, and a rotation-preventing member in engagement with a guide fixed to, or forming part of, the other one of said damper shaft or cylinder barrel, so that a rotational motion of the shaft with respect to the cylinder barrel results in a translational motion of the piston along said longitudinal axis. By not being limited to a travel of less than 360°, this type of damper is particularly suited for use with a multiplying transmission, and thus with lower operating pressures while maintaining compact dimensions.

[0011] The terms "top", "bottom", "upwards", and "downwards", as used in this description, should be understood as relating to the normal orientation of these devices in use. Of course, during their production, distribution, and sale, the devices may be held in a different orientation.

[0012] A preferred embodiment of the invention will be described illustratively, but not restrictively, with reference to the accompanying figures, in which:

Fig. 1 is a perspective view of a first embodiment of a closing mechanism according to the invention;

Fig. 2 is an exploded perspective view of the closing mechanism of Fig. 1;

Fig. 3 is a front view of the closing mechanism of Fig. 1;

Fig. 3a is a cut view of the closing mechanism of Fig. 3 along line A-A;

Fig. 3b is a perspective cutaway view of the same detail;

Fig. 4 is a longitudinal cut view of the closing mechanism of Fig. 1;

Fig. 5 is another perspective view of the closing mechanism of Fig. 1, with a partial cutaway of its damper;

Fig. 5a is a detail view of Fig. 5;

Fig. 6 is a partial perspective view of a second embodiment of a closing mechanism according to the invention;

Fig. 7a is a cut view of the closing mechanism of Fig. 6 during an opening motion;

Fig. 7b is a cut view of the closing mechanism of Fig. 6 during a closing motion.

[0013] Fig. 1 illustrates a gate wing 1 mounted to a frame 2 with a hinge 3 and a closing mechanism 4. This closing mechanism 4 comprises a rail 5 fixed to the gate wing 1, a main body 6 fixed to the frame 2, and an arm 7, with one end 7a fixed to an output 8 of the main body 6, and another end 7b slidingly engaged into the rail 5. The purpose of such a closing mechanism is to close back the gate wing 1 after it has been opened. For this purpose, the output 8 of the main body 6 exerts a torque urging the gate wing 1 back towards a closed position. To prevent that the gate wing 1 be slammed back into the closed position at an excessive speed, the closing mechanism 4 is damped. However, to prevent that this damping unduly increases the force necessary to open the gate wing 1, the closing mechanism 4 presents a significantly higher damping coefficient in the closing direction than in the opening direction. In the prior art this in turn raised the problem of adapting the closing mechanism to right-hand and left-hand opening hinged members, as the damping direction conventionally needs to be changed.

[0014] As shown in Fig. 2, the output 8 is mounted on a transmission 9, which is coupled to a rotatable shaft 10. This rotatable shaft 10 is in turn connected to a damper shaft 11 of a rotation damper 12 and to an end 13a of a helical torsion spring 13. An opposite end 13b of the helical torsion spring 13 is fixed to a worm-wheel 14 which is in self-locking arrangement with a worm gear 15 installed into the housing 16 of the closing mechanism 4. The damper shaft 11 presents a helical outer thread 17 in engagement with a corresponding inner thread 18 of a piston 19 installed in a cylinder cavity 20 of a cylinder barrel 21. The piston 19 also presents radial protrusions 22 for preventing rotation of said piston 19 with respect to the cylinder barrel 21. A rotational movement of the damper shaft 11 is thus converted into a longitudinal movement of the piston 19 within the cylinder cavity 20. A rotation of the damper shaft 11 which, seen from above, runs clockwise, displaces the piston 19 upwards, whereas a counter-clockwise rotation of the damper shaft 11 will displace the piston 19 downwards. Alternative means are however at the reach of the skilled person. For instance, the helical threads could be instead on the piston 19 and the cylinder barrel 21, and the rotation-preventing member placed between the piston 19 and the damper shaft 11. Alternative rotation-preventing members, such as, for example, simple pin-and-groove systems, could also be considered according to the particular needs of the user.

[0015] The cylinder barrel 21 is fixed to the abovementioned housing 16, and the rotation damper 12 also comprises a needle valve 24 which is accessible over a window 25 in said housing 16 for adjusting its damping coefficient.

[0016] Fig. 3 shows a front view of the main body 6 with the arm 7. Cut along line A-A of Fig. 3, the transversal cut view of Fig. 3a illustrates in detail the transmission 9, as does the perspective cutaway of Fig. 3b. This transmission 9 comprises a pinion 26 coupled in rotation to the shaft 10, a first gearwheel 27 directly engaged with said pinion 26, a second gearwheel 28 coupled with said pinion 26 over a reversing gear 29, and a inner toothed arc 30 extending between said first gearwheel 27 and said second gearwheel 28, but not beyond both at the same time. In the illustrated embodiment, the inner toothed arc 30 has a nominal radius four times that of the pinion 26, and is formed on the inside of a cap 31 which covers and protects the transmission 9, and on which the output 8 is formed.

[0017] The main body 6 and the arm 7 are also illustrated in their assembled state as a longitudinal cut view on Fig. 4. As can be seen here, a lid 32 closes the top of the cylinder cavity 20 and holds the damper shaft 11. The piston 19, shown here in its lowest position, divides the cylinder cavity into a first side 20a and a second side 20b, wherein said first side 20a also includes a piston cavity 33, which, as can be seen in Figs. 5 and 5a, is in substantially unrestricted fluid communication with the rest of said first side 20a over at least one duct 34 in the damper shaft 11. As can also be seen in Figs. 5 and 5a, the first and second side 20a, 20b of the cylinder cavity 20 are in fluid communication with each other over the duct 35, which is restricted by the needle valve 24. Turning back to Fig. 4, a one-way valve 36, at the bottom of the piston 19, is also interposed between said first and second side 20a, 20b of the cylinder cavity 20, and set to open when the fluid pressure in the first side 20a, here the upper side, is higher than that in the second, lower, side, so as to let hydraulic fluid flow from said first side 20a into said second side 20b. To prevent overload, in the illustrated embodiment, a relief valve 37 is also incorporated into said one-way valve 36, so as to allow flow from the second side 20b into the first side 20a, but only if the overpressure in said second side 20b increases dangerously.

[0018] Turning back to Figs. 3, 3a and 3b, when in the illustrated embodiment said output 8 is rotated counter-clockwise, seen from above, moving the toothed arc 30 away from the illustrated neutral position between the first and second gearwheels 27, 28 towards the first gearwheel 27, and the toothed arc 30 engages with the first gearwheel 27. Over said first gearwheel 27 and pinion 26, the toothed arc 30 rotates the shaft 10 in a clockwise direction against the coil torsion spring 13. Since the toothed arc 30 has a nominal radius four times that of the pinion 26, there is a 4:1 multiplication ratio between the output 8 and the pinion 26, so that a rotation of the output 8 over 90° is converted into a rotation of the pinion 26 and shaft 10 over 360°.

[0019] On the other hand, when the output 8 is rotated clockwise from the illustrated position, the toothed arc 30 engages instead the second gearwheel 28, and will turn said shaft 10, over said second gearwheel 28, reversing gear 29 and pinion 26, in the same clockwise direction, and with the same 4:1 multiplication ratio, against the coil torsion spring 13.

[0020] Said clockwise rotation of the shaft 10 and the damper shaft 11 will displace the piston 19 upwards away from the illustrated lower position. As the one-way valve 32 allows flow from the first side 20a of the cylinder cavity 20 into the second side 20b, the rotation damper 12 will only oppose slight resistance to this rotation.

[0021] Once the output 8 is released, whether it has been rotated clockwise or counter-clockwise from the neutral position, the coil torsion spring 13 will return it towards the neutral position by turning the shaft 10 counter-clockwise. This, in turn, will move the piston 19 downwards back towards the illustrated lower position. As the one-way valve 32 will remain closed, the rotation damper 12 will produce a higher damping torque, controllable over the needle valve 24 restricting the duct 31. Only if there is a risk of overload, the relief valve 33 will open to relief the overpressure in the second side 20b. The return of the output 8 towards the neutral position will thus be more highly damped, independently of whether it was displaced clockwise or counter-clockwise from said neutral position. This makes the illustrated closing mechanism 4 suitable for both right- and left-handedly hinged wings, and this just by changing the orientation of the arm 7.

[0022] Because the highest hydraulic fluid pressures will be reached in the second side 20b of the cylinder cavity 20, and because the cylinder barrel 21 is cup-shaped, and completely closed at the bottom, without any opening or joint in communication with said high-pressure second side 20b of the cylinder cavity 20, the illustrated hydraulic rotation damper 12 will not easily leak, and is therefore particularly suited for outdoors applications, such as gate closing mechanisms.

[0023] Although in the embodiment illustrated in Figs. 1-5a the movement of the damper piston 19 is substantially parallel to the rotation axis of the shaft 10 of the closing mechanism 6, alternative damper and actuator configurations can also be considered. In an alternative embodiment illustrated in Figs. 6, 7a and 7b, the shaft 10' is connected to the damper piston 19' over a rack-and-pinion transmission, so that the movement of the piston 19' within the cylinder cavity 20' is substantially perpendicular to the rotation axis of the shaft 10'. As in the first embodiment, the piston 19' divides said piston cavity 20' into a first side 20a' and a second side 20b' in fluid communication with each other over a duct 35' restricted by a needle valve 24'. The damper 12' also comprises a one-way valve 36' allowing flow of fluid from the first side 20a' to the second side 20b' within the piston 19'.

[0024] In the illustrated embodiment, the actuator is formed by a coil compression spring 13' within the cylinder cavity 20'. However, it could also alternatively take the form of a torsion spring external to the damper 12', as in the first embodiment.

[0025] The shaft 10' is connected to the same transmission (not illustrated) than that of the first embodiment, so that, regardless of whether the output (not illustrated) connected to the shaft 10' through said transmission is rotated clockwise or counter-clockwise from a neutral position, the shaft rotates clockwise, displacing the piston 19' against the compression spring 13', as illustrated in Fig. 7a. The one-way valve 36' allows the hydraulic fluid to flow from the first side 20a' to the second side 20b', opposing scant resistance to the movement of the piston 19'. Once the output is released, the spring 13' will push the piston 19' back, as illustrated in Fig. 7b. However, since the one-way valve 36' will not allow flow from the second side 20b' to the first side 20a', all the returning hydraulic fluid will have to flow through the restricted duct 35', damping the return movement of the piston 19' and the output.

[0026] Although the present invention has been described with reference to specific exemplary embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader scope of the invention as set forth in the claims. For instance, a different type of substantially unidirectional damper, including, for instance, a friction damper, could be used in place of the illustrated hydraulic damper. The closing mechanism could also be formed as a hinge, with the rotational output 8 acting directly onto the hinged wing or frame, instead of over the arm 7. The housing of the closing mechanism could be fixed to a fixed frame, and the output connected to the hinged member, as illustrated in Fig. 1, or, alternatively, the housing of the closing mechanism could be fixed to the hinged member and the output connected to the fixed frame, as in US 6,891,479 B1. Accordingly, the description and drawings are to be regarded in an illustrative sense rather than a restrictive sense.

Claims

1. A bidirectional closing mechanism (6) for hinged members (1) comprising:

- a rotational output (8);

- a shaft (10);

- an actuator (13) connected to said shaft (10) for urging said shaft (10) in a first direction of rotation around a main axis of the shaft (10); and

- a damper (12); coupled to said shaft (10), for damping rotation of said shaft (10) with a substantially higher damping coefficient in said first direction of rotation than in an opposite second direction of rotation; and

the mechanism (6) being characterised in that it further comprises, between said output (8) and said shaft (10):

- a transmission (9) comprising :

■ a pinion (26) coupled to said shaft (10);

■ a first gearwheel (27) directly engaged with said pinion (26);

■ a second gearwheel (28) coupled with said pinion (26) over a reversing gear (29), and

■ a toothed arc (30), coupled to said output (8), and extending between said first gearwheel (27) and said second gearwheel (28), but not beyond both at the same time.

2. A closing mechanism (6) according to claim 1, wherein said toothed arc (30) presents a larger nominal radius than said pinion (26), preferably at least twice as large.

3. A closing mechanism (6) according to any one of the previous claims, wherein said toothed arc (30) presents an inner toothing.

4. A closing mechanism (6) according to any one of the previous claims, wherein said actuator comprises a resilient element (13), preferably in the form of a torsion spring, in particular a coil torsion spring.

5. A closing mechanism (6) according to any one of the previous claims, further comprising a mechanism for adjusting a preload of said actuator.

6. A closing mechanism (6) according to claim 5, wherein said preload adjusting mechanism comprises a worm (15) in self-locking engagement with a worm-wheel (14) connected to said actuator.

7. A closing mechanism (6) according to any one of the previous claims, wherein said damper (12) is hydraulic.

8. A closing mechanism (6) according to claim 7, wherein said damper (12) comprises:

- a cylinder cavity (20) enclosed by a cylinder barrel (21) having a longitudinal axis;

- a damper shaft (11), rotatable with respect to said cylinder barrel (21) substantially around said longitudinal axis ;

- a piston (19) placed within said cylinder barrel (21) so as to divide the cylinder cavity (20) into a first side (20a) and a second side (20b) in restricted fluid communication with each other, said piston (19) comprising:

■ an helical thread (18) in engagement with a corresponding helical thread (17) on either the cylinder barrel (21) or the damper shaft (11), and

■ a rotation-preventing member (22) in engagement with a guide forming part of or fixed to the other one of said damper shaft (11) or cylinder barrel (21), so that a rotational motion of the damper shaft (11) with respect to the cylinder barrel (21) results in a translational motion of the piston (19) along said longitudinal axis; and

- a one-way valve (36) from said first side (20a) to said second side (20b) of the cylinder cavity (20).

Drawing