EP3563022B1

EP3563022B1 - Hydraulically damped actuator and self-closing hinge comprising the actuator

Info

Publication number: EP3563022B1
Application number: EP17823166.8A
Authority: EP
Inventors: Joseph Talpe
Original assignee: Locinox NV
Current assignee: Locinox NV
Priority date: 2016-12-27
Filing date: 2017-12-22
Publication date: 2023-06-07
Anticipated expiration: 2037-12-22
Also published as: EP3563022A1; WO2018122210A1; EP3563022C0; PL3563022T3

Description

The present invention relates to hydraulically damped actuator for closing a closure member hinged to a support. The present invention also relates to a hydraulically damped, self-closing hinge for hinging a closure member to a support which comprises the actuator. The actuator comprises: an energy storing mechanism configured for storing energy when said closure member is being opened and for restoring said energy to effect closure of said closure member, the energy storing mechanism comprising a first and a second actuation member and a spring mechanism arranged between both actuation members, the actuation members being rotatable with respect to one another around a rotation axis in a first mutual direction to store said energy in said spring mechanism and in a second mutual direction, which is opposite to said first mutual direction, to restore said energy; a damping mechanism configured for damping a closing movement of said closure member, the damping mechanism comprising: a closed cylinder cavity that has a longitudinal direction and is filled with a volume of hydraulic fluid; a damper shaft having a first end extending into the cylinder cavity, the damper shaft being rotatable around a rotation axis that extends substantially in said longitudinal direction and being configured to transfer the opening and closing movement of the closure member to the damping mechanism; a piston within said cylinder cavity so as to divide the cylinder cavity into a high pressure compartment and a low pressure compartment, the piston being operatively coupled to said damper shaft to be movable between two extreme positions in said longitudinal direction; a one-way valve allowing fluid flow from the low pressure compartment to the high pressure compartment when said closure member is being opened; and at least one restricted fluid passage between the compartments; a pressure compensation mechanism for compensating changes of the volume of said hydraulic fluid upon temperature variations thereof; and a first and a second connection element, the first connection element being configured to connect the actuator to the support and the second connection element being configured to connect the actuator to the closure member, the energy storing mechanism being operatively connected with said first connection element and said second connection element and the damping mechanism being operatively connected with said first connection element and said second connection element.
Such a hydraulically damped actuator is disclosed in EP-A-2295693 and EP-A-2356305 . The actuator disclosed therein is intended to be mounted to an outdoors hinged closure member, e.g. a gate, to effect closure thereof. The closed cylinder cavity is filled with hydraulic fluid to damp the motion of the piston. In particular, when the closure member is closed, the hydraulic fluid is located in the low pressure compartment. By opening the closure member the piston is displaced and hydraulic fluid flows through the one-way valve and the restricted fluid passage to the high pressure compartment without severely affecting the motion of the piston. When the closure member is opened, the hydraulic fluid is located in the high pressure compartment. When closing the closure member, the one-way valve is closed and hydraulic fluid is forced to flow from the high pressure compartment to the low pressure compartment via the restricted fluid passage thereby acting against the sliding movement of the piston, thus damping the closing movement of the closure member.
A disadvantage of this actuator is that it could be damaged due to an expansion of the hydraulic fluid. This is especially the case when the hydraulic fluid contains no gas, or no gas bells or bubbles, the presence of which would allow the hydraulic fluid to expand but may cause problems with the functioning of the actuator as the gas bubbles may hamper the dampening effect of the actuator. Specifically, as actuators are used outdoor large temperature variations are not uncommon. For example, summer temperatures above 70°C. when the hydraulic damper is exposed to sunlight and winter temperatures below -30°C. are possible, i.e. temperature variations up to and exceeding 100°C. Moreover, there are also the daily temperature variations between night and day which can easily exceed 30°C when the actuator is subjected to direct sunshine. These temperature variations cause expansion, and also contraction, of the hydraulic fluid, which expansion causes significant pressures in the closed cylinder cavity possibly resulting in damage to the actuator.
A know solution to this problem is to include a small quantity of air or another gas inside the closed cylinder cavity, e.g. up to 5% of the total volume of the hydraulic fluid. This quantity can be added on purpose, but is, more often, the result of not carefully filing the entire closed cylinder cavity. The air is compressed as the hydraulic fluid expands and vice versa without excessive pressures in the closed cylinder cavity. However, a downside of this solution is that the air can be displaced through the restricted fluid passage resulting in a loss in pressure on the piston and thus an uneven damping of the closure member. As such, air is ideally avoided in a hydraulically damped actuator.
Another known solution is proposed in EP-A-2840212 in which a compressible closed-cell foam element, i.e. a pressure compensation mechanism, is introduced into the closed cylinder cavity, which is formed by the entire actuator. The element is compressed when the hydraulic fluid expands and vice versa, thereby avoiding excessive pressures. However, the actuator is intended only for indoor use with a limited range in temperature variations, as compared to outdoor use, making it possible to use a small element thereby maintaining a compact actuator. Furthermore, the foam element is usually not exposed to low temperatures, which frequently occur outdoors, at which temperatures the foam would become brittle and would be damaged by the daily cycle of expansion and contraction, especially during the winter.
It is an object of the present invention to provide a hydraulically damped actuator that is more resistant to temperature variations, in particular in outdoors areas.
This object is achieved according to the invention in that said pressure compensation mechanism comprises an expansion channel with a plunger that fits into the expansion channel and is slidably received therein, the plunger dividing the expansion channel into a first compartment which is in fluid communication with said cylinder cavity and a second compartment that is sealed off from the first compartment by said plunger, the second compartment allowing the plunger to slide within the expansion channel to compensate said changes of the volume of the hydraulic fluid.
The expansion channel provides sufficient space to allow the hydraulic fluid to expand without resulting in excessive pressures that could damage the closed cylinder cavity even for large outdoors temperature variations. As such, the actuator is more resistant to temperature variations. Moreover, the plunger seals off the first compartment from the second compartment ensuring that the contents of the second compartment, e.g. gas or air, cannot enter in the first compartment. As such, the gas or air in the expansion channel cannot enter the closed cylinder cavity and thus cannot disrupt the normal operations of the hydraulic damper.
In an embodiment of the present invention said second compartment comprises a biasing member urging the plunger towards said second compartment to pressurize the hydraulic fluid. Preferably, said biasing member comprises a compression spring.
The biasing member exerts a pressure on the hydraulic fluid thereby alleviating the effects caused by negative pressures in the hydraulic fluid that may act on sealing ring or rings in the hydraulic actuator, which negative pressures could cause air or gas to be sucked into the closed cylinder cavity via the sealing ring.
In an embodiment of the present invention the plunger is provided with a seal that engages an inner surface of the expansion channel.
The seal is an example of how the plunger may seal off the second compartment from the first compartment in an easy manner.
In an embodiment of the present invention said first compartment of the expansion channel is part of said low pressure compartment.
By fluidly connecting the expansion channel with the low pressure compartment, the plunger and the biasing member in the expansion channel are not exposed to the high pressures when closing the closure member. Furthermore, if the expansion channel would be fluidly connected to the high pressure compartment this would affect the normal operation of the damping mechanism.
In an embodiment of the present invention said second compartment of the expansion channel is filled with a gas, in particular with air.
In an embodiment of the present invention the hydraulic fluid is free of gas bells or bubbles.
In an embodiment of the present invention the expansion channel has a cylindrical cross-section.
In an embodiment of the present invention said damper shaft is rotatable around a rotation axis that extends substantially in said longitudinal direction with said first end having an end face and a portion with a non-circular cross-section, the damping mechanism comprising a spindle made of a synthetic material and having a recess with a non-circular cross-section fitting onto said portion of the damper shaft, the spindle being fixed onto said first end of the damper shaft and having an outer threaded portion with a screw axis which coincides with said rotation axis, the piston having an inner threaded portion with a screw axis which also coincides with said rotation axis, the outer threaded portion of the spindle on the damper shaft being in engagement with the inner threaded portion of the piston to operatively couple the piston to said damper shaft.
The spindle provides a simple design to transfer the rotation of the damper shaft into a translation of the piston.
In a preferred embodiment of the present invention said recess in the spindle has a bottom which engages said end face of the damper shaft, the spindle being fixed to the damper shaft by at least one bolt that is bolted through the bottom of the spindle into the end face of the damper shaft, the at least one bolt having a head which is sunk into the bottom of the spindle and being offset with respect to said rotation axis to irrotatably fasten the spindle to the damper shaft.
By fastening the spindle to the damper shaft by at least one bolt that is bolted through the bottom of the spindle into the end face of the damper shaft and that is offset with respect to the rotation axis and has a head which is sunk into the spindle, the at least one bolt also transfers a rotational motion of the damper shaft to the spindle. As such, less force is exerted onto the recess with the non-circular cross-section in the spindle which is thus less prone to wear out and cause leeway between the piston and the damper shaft.
In an embodiment of the present invention the expansion channel is formed by a cavity inside the damper shaft.
In an alternative embodiment of the present invention the expansion channel is formed by a cavity adjacent to said cylinder cavity.
These embodiments provide flexible design options for the actuator.
The spring provides a simple design to store energy from the pivoting motion of the hinge members.
In an embodiment of the present invention the actuator is configured to be mounted with said longitudinal direction having a near vertical orientation.
It is an object of the present invention to provide a hydraulically damped, self-closing hinge that is more resistant to temperature variations, in particular in outdoors areas.
This object is achieved according to the invention by a hydraulically damped, self-closing hinge for hinging a closure member to a support, the hinge comprising: a first hinge member comprising a first barrel and a first leaf fixed to said first barrel and configured to be fixed to one of: the support and the closure member; a second hinge member pivotably mounted on the first hinge member through the intermediary of a first and a second rolling bearing, the second hinge member comprising a second barrel and a second leaf fixed to said second barrel and configured to be fixed to the other one of: the support and the closure member; and an actuator as described above, the first connection element being formed by one of: the first and the second hinge member and the second connection element being formed by the other one of: the first and the second hinge member.
This hinge has the same advantages as the actuator described above.
In an embodiment of the present invention said first barrel has a main body and a hollow shaft extending from said main body with the damper shaft extending through the hollow shaft, the second barrel being pivotably mounted on said hollow shaft through the intermediary of said rolling bearings each having an inner race and an outer race, the inner races of said rolling bearings radially engaging an outer surface of said hollow shaft, the outer races of said rolling bearings radially engaging an inner surface of said second barrel, the inner race of the first rolling bearing being axially engaged by a first abutment on said first barrel, the inner race of the second rolling bearing being axially engaged by a second abutment fixed onto said hollow shaft, the outer race of the first rolling bearing being axially engaged by a third abutment on the inner surface of said second barrel, the outer race of the second rolling bearing being axially engaged by a fourth abutment on the inner surface of said second barrel.
By placing the rolling bearings between the different abutments, one of the rolling bearings will support the weight of a right-handed closure member while the other of the rolling bearings will support the weight of a left-handed closure member. Moreover, due to the damper shaft being placed through the hollow shaft, the pivoting motion of the hinge members relative to one another is transferred to the damping mechanism internally thus avoiding the necessity of having three knuckles with a leaf connecting two of the knuckles. As such, the hinge is able to be formed as a barrel hinge having only two knuckles, with the first knuckle being formed by the first barrel and the second knuckle being formed by the second barrel, which is very compact.
The invention will be further explained by means of the following description and the appended figures.

Figures 1A and 1B show a longitudinal cross-section of a hinge of the present invention mounted on a support and a left-handed and a right-handed closure member in the closed position of the closure member.
Figures 2A to 2D show the same longitudinal cross-section as Figure 1A with the closure member being opened over 90°; fully opened over 180°; and starting to close; and half closed over 90°.
Figures 3A to 3D show the same longitudinal cross-section as Figure 1B with the closure member being opened over 90°; fully opened over 180°; and starting to close; and half closed over 90°.
Figure 4A shows a partly exploded view of the complete hinge.
Figure 4B shows a partly exploded view of the first hinge member.
Figure 5A shows a perspective view of the damper shaft and the piston.
Figure 5B shows a detailed cross-section of the spindle connected to the damper shaft.
Figure 5C shows an exploded view of the damper shaft and the spindle illustrated in Figure 5B.
Figures 6A and 6B show a longitudinal cross-section of the hinge at the location of the expansion channel present therein.
Figures 7A and 7B show a longitudinal cross-section at the location of an alternative expansion channel of the hinge.

The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims.
The invention generally relates to a hydraulically damped actuator for closing a closure member 1 hinged to a support 2. The closure member 1 may be a door, a gate or a window, in particular an outdoors door or gate that may be subjected to large temperature variations. The support 2 may, for example, be a wall or a post. The actuator comprises a first and a second connection element, the first connection element being configured to connect the actuator to the support 2 and the second connection element being configured to connect the actuator to the closure member 1. The actuator further comprises an energy storing mechanism and a damping mechanism, both of which are operatively connected with the closure member 1 and the support 2 via the first and second connection elements. The energy storing mechanism is configured for storing energy when the closure member 1 is being opened and for restoring the energy to effect closure of the closure member 2. The damping mechanism is configured for damping a closing movement of the closure member 1.
In a first embodiment, the actuator is provided as a separate device that is used in combination with hinges, which actuator can be retrofitted onto an existing hinged closure member 1. Such separate devices are, for example, disclosed in EP-B-2356304 , EP-B-2470739 and US-A-2009/107051 . Details of combining the devices disclosed therein with the actuator of the present invention are given below. Preferably, the closure member 1 is hinged to the support 2 with a height adjust mechanism for adjusting the height of the closure member 1 with respect to the support 2 as described in EP-B-1528202 and with an anti-theft mechanism as described in EP-B-2778330 .
In a second embodiment, the actuator is provided in the form of a hinge as illustrated in Figures 1A and 1B. In other words, the closure member 1 is hinged to the support 2 by means of a hydraulically damped, self-closing hinge. The hinge comprises a first and a second hinge member 4, 5 with the first hinge member 4 being fixed to the support 2 and the second hinge member 5 being fixed to the closure member 1 for both a right-handed and a left-handed closure member 1 as illustrated in Figures 1A and 1B respectively. In other words, the hinge is turned upside down for a left-handed closure member 1 with respect to its orientation for a right-handed closure member 1. Therefore, the first hinge member 4 may also be referred to as the fixed hinge member 4 and the second hinge member may also be referred to as the moveable hinge member 5.
As illustrated in Figures 1A and 1B, the fixed hinge member 4 comprises a first barrel 6 fixed to a first leaf 8, also referred to as the fixed barrel 6 and the fixed leaf 8, while the moveable hinge member 4 comprises a second barrel 7 fixed to a second leaf 9, also referred to as the moveable barrel 7 and the moveable leaf 9. The leaves 8, 9 are used to fix the hinge to the closure member 1 and to the support 2 while the barrels 6, 7 function as the knuckles of the hinge and also house the energy storing and the damping mechanisms. In particular, as illustrated in Figures 4A and 4B, the fixed leaf 8 is angled to match an angle of the support 2 so as to be always fixed in a same position with respect to the support, i.e. in order to be always aligned with the other hinge used to hinge the closure member to the support.
Preferably, the moveable leaf 9 is arranged such that it is possible to move the hinge, in particular the hinge axis of the hinge, closer and further away with respect to the closure member 1 and the fixed leaf 9 is arranged such that it is possible to adjust the height of the closure member 1 with respect to the support 2. In an embodiment, the fixed leaf 8 comprises horizontal grooves 77 that are placed above one another (shown in Figure 4B) that cooperate with grooves on mounting plates applied underneath the heads of the bolts 80 used to mount the fixed leaf 8 onto the support 2. The fixed leaf 9 also has two vertical slots (not shown), on above the other, for receiving the bolts 80. The cooperating grooves and the vertical slots enable to move the closure member 1 higher and/or lower with respect to the support 2. Similarly, the moveable leaf 9 comprises vertical grooves 78 that are placed sideways with respect to one another and horizontal slots 88 (shown in Figure 4A). The vertical grooves 78 cooperate with grooves on mounting plate applied underneath the heads of the bolts 80 used to mount the moveable leaf 9 onto the closure member 1. These cooperating grooves and horizontal slots 88 enable to move the closure member 1 closer and/or further away with respect to the support 2.
The leaves 8, 9 are preferably fixed to the support 2 and the closure member 1 respectively using fixture sets as described in EP-B-1907712 , i.e. by inserting bolts 80 through fixation elements 81 into nut elements 79 that automatically fasten due to a square cross-section that fits into a square section (not shown) of a locking plate 82 ( shown in Figure 4A).
In the illustrated embodiments, each of the leaves 8, 9 is covered with a cover cap 84, 85 to cover the grooves 77, 78 and the fixture sets 79, 80.
In a preferred embodiment, the hinge members 4, 5 are extruded profiles with certain sections being milled and/or grinded away to form ledges, collars, protrusions, etc.
Preferably, the hinge members 4, 5 are manufactured from extruded aluminium which is less porous as cast aluminium so that it is leak-free with respect to hydraulic fluid.
Figures 1A and 1B show a longitudinal cross-section of the hydraulically damped, self-closing hinge mounted on a closed right-handed and a closed left-handed closure member 1 respectively. Both barrels 6, 7 have a longitudinal direction 10, 11, which longitudinal directions 10, 11 are preferably substantially the same. The moveable barrel 7 is pivotably mounted onto a hollow shaft 12 that forms a part of the fixed barrel 6 using two ball bearings 13, 14. The barrels 6, 7 thus act as knuckles of the hinge with the moveable barrel 7 being pivotable with respect to the fixed barrel 6 around a pivot axis 15 which, preferably, extends in the longitudinal directions 10, 11.
The ball bearings 13, 14 together with a fixed collar 16 on the inner surface of the moveable barrel 7, a ring 17 fixed onto the hollow shaft 12 and a ledge 18 on the fixed barrel 6 act as the pin of the hinge to keep the two hinge members 4, 5 fixed to one another and to enable a pivoting motion of the two hinge members 4, 5 with respect to one another.
Specifically, the inner races 19, 20 of the ball bearings 13, 14 radially contact the outer surface of the hollow shaft 12 and the outer races 21, 22 of the ball bearings radially contact the inner surface of the moveable barrel 7. The ball bearings 13, 14 thus enable a pivoting motion of the moveable barrel 7 with respect to the hollow shaft 12 and thus with respect to the fixed barrel 6.
The first inner race 19, i.e. the inner race 19 of the first ball bearing 13, axially engages with the ledge 18 of the fixed barrel 6 and the first outer race 21, i.e. the outer race 21 of the first ball bearing 13, axially engages with the collar 16. Therefore, for the right-handed closure member 1 illustrated in Figure 1A, there is the following chain of support. The first hinge member 4 is fixed to and supported by the support 2; the first ball bearing 13 is supported by the first hinge member 4 as the first inner race 19 rests upon a first abutment 23 formed by the ledge 18 of the fixed barrel 6; the first ball bearing 13 supports the second hinge member 5 as a third abutment 25 formed by the collar 16 rests upon the first outer race 21; and the closure member 1 is fixed to and supported by the second hinge member 5. As such, for a right-handed closure member 1 to which the second hinge member 5 is fixed, the closure member 1 is supported via the first ball bearing 13.
The second inner race 20, i.e. the inner race 20 of the second ball bearing 14, axially engages with the ring 17 that is fixed to the hollow shaft 12 of the fixed barrel 6 and the second outer race 22, i.e. the outer race 22 of the second ball bearing 14, axially engages with the collar 16. Therefore, for the left-handed closure member 1 illustrated in Figure 1B, there is the following chain of support. The first hinge member 4 is fixed to and supported by the support 2; the second ball bearing 14 is supported by the first hinge member 4 as the second inner race 20 rests upon a second abutment 24 formed by the ring 17 of the fixed barrel 6; the second ball bearing 14 supports the second hinge member 5 as a fourth abutment 26 formed by the collar 16 is supported by the second outer race 22; and the closure member 1 is fixed to and supported by the second hinge member 5. As such, for a left-handed closure member 1 to which the second hinge member 5 is fixed, the closure member 1 is supported via the second ball bearing 14.
It will be appreciated that, although the ball bearings 13, 14 have been described as engaging various surfaces, in other embodiments, various spacer elements may be interposed between the ball bearings 13, 14 and the respective abutments 23, 24, 25, 26 and the outer surface of the hollow shaft 12 and the inner surface of the moveable barrel 7.
Moreover, in other embodiments, one or both the ball bearings 13, 14 may be replaced by a same number of rolling bearings including but not limited to cylindrical roller bearings, spherical roller bearings, gear bearings, tapered rolling bearings and needle roller bearings.
Furthermore, it will be appreciated that the collar 16 which acts as both the third and fourth abutments 25, 26 may be implemented in various alternative ways. For example, the collar 16 may be split into two parallel collars by an annular groove; the collar 16 may be discontinuous, e.g. a ring of protrusions from the inner surface of the moveable barrel 7 may also form the collar 16; axial protrusions may be provided onto the collar 16 in which case the third and fourth abutments 25, 26 are formed by these projections; etc. Similarly, the first abutment 23 formed by the ledge 18 on the fixed barrel 6 may also be formed by a further collar on the outer surface of the hollow shaft 12 or may be formed by multiple protrusions therefrom or by axial protrusions from the ledge 18. One continuous collar 16 on the inner surface of the moveable barrel is however preferred. This collar is preferably part of the extruded profile and is produced by widening the boring in the extruded profile above and below the collar so that the collar remains. In this way, a strong collar is obtained, which is made of extruded aluminium and which can resist high stresses.
In the illustrated embodiment, the ring 17 is formed by an actuation member of the energy storing mechanism (as described below) which is fastened to the hollow shaft 12 by a ring screw or nut 27 that is screwed onto a threaded portion 3 of the hollow shaft 12 (as illustrated in Figure 4A). Preferably, the threaded portion 3 is located at the free end of the hollow shaft 12. The actuation member of the energy storing mechanism is rotatably locked with respect to the hollow shaft 12 by having a non-circular cross-section, in particular a flat side 67 as illustrated in Figure 4A that abuts with a corresponding flat side 83 of the hollow shaft 12.
The configuration of the ball bearings 13, 14, the ledge 18 and the ring 17 is advantageous as it allows the hinge to be easily assembled. In particular, the fixed hinge member 4 is assembled first with the first ball bearing 13 being placed around the hollow shaft 12. Afterwards, the moveable hinge member 5 is placed onto the hollow shaft 12 with the collar 16 resting on the first ball bearing 13. The second ball bearing 14, together with the other internal elements in the moveable hinge member 5, are then placed via an opening in the top of the moveable hinge member 5 which is finally sealed with a second end cap 28.
The energy storing mechanism is contained in the moveable barrel 7 and comprises a first actuation member 29 formed by the ring 17, a second actuation member 30 and a torsion spring 31 connected with one end to the first actuation member 29 and with the other end to the second actuation member 30. The second actuation member 30 is ring-shaped and placed onto the free end of a damper shaft 32. The second actuation member 30 is rotatably locked to the moveable barrel 7 and the damper shaft 32 by a pin 33 (shown in Figure 4A) that is placed in respective openings 34, 35, 57 in the damper shaft 32, the first actuation member 29 and the moveable hinge member 5 (shown in Figure 4A). The second actuation member 30 further comprises a hole (not shown) in which an end of the torsion spring 31 is placed. In this way, the moveable barrel 7, the second actuation member 30, the damper shaft 32 and one end of the torsion spring 31 are all irrotatably coupled to one another and to the closure member 1. The first actuation member 29, formed by the ring 17, is irrotatably fixed to the hollow shaft 12, and thus to the fixed barrel 6, by the ring screw 27. The first actuation member 29 further comprises a hole 36 (shown in Figure 4A) in which the other end of the torsion spring 31 is placed. This end of the torsion spring 31 is thus irrotatably coupled to the fixed hinge member 4 and thus to the support 2.
In a preferred embodiment, the energy storage mechanism also comprises padding to prevent the spring 31 from buckling due to the large forces exerted thereon. In the illustrated embodiments, the padding comprises three rings 37 placed around the damper shaft 32 in the opening between the damper shaft 32 and the torsion spring 31. The padding rings 37 are free to rotate with the damper shaft 32 and do not contact the torsion spring 31 thus causing no significant friction.
The damper shaft 32 provides the coupling between the energy storing mechanism and the damping mechanism, and transfers the opening and closing movement of the closure member 1 to the damping mechanism. The damper shaft is rotatable around a rotation axis 38 that is substantially the same as the pivot axis 15 and the longitudinal directions 10, 11. The damper shaft 32 extends through the hollow shaft 12, as such entering the fixed barrel 6 in which the damping mechanism is housed.
The hydraulic damper mechanism comprises the fixed barrel 6 which forms a part of the fixed hinge member 4 and which is closed off at the bottom by an oil cap 39 to define a closed cylinder cavity 40. This cylinder cavity 40 has a longitudinal direction which is the same as the first longitudinal direction 10. The damper mechanism further comprises a piston 41 placed in the fixed barrel 6 to divide the cylinder cavity 40 into a high pressure compartment 42 and a low pressure compartment 43 (illustrated in Figures 2A, 2D, 3A and 3D).
A perspective view of the damper shaft 32 and the piston 41 placed thereon is shown in Figure 5A, which illustrates that the piston 41 has three outward projections 44 which are guided in three grooves 45 in a base element 46 (shown in Figure 4B) which is also arranged in the cylinder cavity 40. The base element 46 fits in the fixed hinge member 4 and is irrotatably locked therein by means of three bolts 47 (shown in Figure 4B) which are bolted into corresponding holes in the top of the fixed hinge member 4. By such a configuration, the piston 41 can substantially not rotate within the fixed barrel 6 and is slidable in the longitudinal direction 10 of the cylinder cavity 40 between two extreme positions, namely a closed position illustrated in Figures 1A and 1B and an open position illustrated in Figures 2B, 2C, 3B and 3C.
The hydraulic damper mechanism further comprises the rotating damper shaft 32. As can be seen in Figure 1A and 1B and as described above, the rotating damper shaft 32 is irrotatably coupled to the moveable hinge member 5. The damper shaft 32 therefore rotates together with the closure member 1. In particular, the damper shaft 32 rotates over substantially the same angle with respect to the fixed barrel 6 as the angle over which the moveable hinge member 5 rotates with respect to the fixed hinge member 4.
As illustrated in Figures 1A and 1B, at one end, the damper shaft 32 enters the low pressure compartment 43 of the cylinder cavity 40 through the side of the fixed barrel 6, i.e. the hollow shaft 12. A third bearing 48 and a seal 49 are provided between the damper shaft 32 and the fixed hinge member 4, as also illustrated in the exploded view of Figure 4B. The third bearing 48 provides a smooth and easy rotation between the damper shaft 32 and the fixed barrel 6 and also aligns the damper shaft 32 with the hollow shaft 12 with a tolerance of less than 100 µm, preferably less than 20 µm. As such, friction and wear of the seal 49 can be kept to a minimum so that it remains liquid tight even after prolonged use. The hinge can thus be mounted upside down without hydraulic liquid escaping by gravity along the rotating damper shaft 32.
In order to convert the rotational motion of the damper shaft 32 into a translational motion of the piston 41 in the cylinder cavity 40, a spindle 50 is provided between the damper shaft 32 and the piston 41, which spindle is preferably made of a synthetic material which can easily be moulded into the required shape. Preferably, the spindle 50 is injection moulded from a thermoplastic material. Specifically, the spindle 50 is mounted onto an end 52 of the damper shaft 32. In order to convert the rotational motion of the spindle 50 into a translational motion of the piston 41 in the cylinder cavity 40, the spindle 50 is provided with an outer threaded portion 55 that engages an inner threaded portion 56 on the piston 41. Specifically, the outer threaded portion 55 is provided with a first, external (male) screw thread which has a screw axis which substantially coincides with the rotation axis 38 of the damper shaft 32 and which cooperates with an internal (female) screw thread on the piston 41. Since the piston 41 is irrotatably fixed within the fixed barrel 6, via the upward projections 44 and grooves 45, the piston 41 slides with respect to the fixed barrel 6. In particular, the piston 41 moves towards the damper shaft 32 when the closure member 1 is opened and it moves away from the damper shaft 32 when the closure member 1 is closed. In the illustrated embodiments, the screw threads are therefore right-handed screw threads.
To keep the hinge as compact as possible, no gearing or reduction is provided between the damper shaft 32 and the piston 41. As such, the threaded portions 55, 56 have a screw thread with a high lead angle. Preferably, the outer threaded portion 55 has a lead angle of at least 45° and more preferably at least 55° and most preferably at least 60°. In the illustrated embodiment, the lead angle is equal to about 66°. Moreover, the outer threaded portion 55 preferably has at least 5 starts and more preferably at least 7 starts and 10 starts in the illustrated embodiments. The larger lead angle increases the amount of force that is exerted onto the spindle 50 when transferring a rotation from the damper shaft 32 to a sliding motion of the piston 41. These large forces are known to lead to a deformation of the spindle 50 after a period of time.
To counter such problems, the spindle 50 is irrotatably coupled to the damper shaft 32 in two ways as shown in the exploded view of Figure 5C. First, the spindle 50 is provided with a recess 51 having a non-circular cross-section, specifically, with two flat sections. The proximal end 52 of the damper shaft 32 is provided with a corresponding non-circular cross section on which the spindle 50 is mounted. Moreover, the spindle 50 is fastened to the end face 68 of the damper shaft 32 with two bolts 53. The bolts 53 are bolted through a bottom 86 of the spindle 50 into the end face 68 of the damper shaft 32 as illustrated in the cross-sectional view of Figure 5B. In particular, each of the bolts 53 is offset with respect to the rotation axis 38 of the damper shaft 32 and has a head 54 that is sunk into the spindle 50. The head 54 of the bolt 53 used to fix the spindle 50 to the damper shaft 32 has, in general, a circular cross-section so that it can engage the inner wall of the recess in the bottom of the spindle wherein it is received. Preferably, the lateral side of the circular head has a height which is equal to at least 1 mm, more preferably of at least 2 mm. In this configuration, the bolts 53 transfer a significant part of the rotation of the damper shaft 32 to the spindle 50 causing a significant decrease in pressure on the recess 51 and thus a lower chance that the plastic spindle 50, in particular the recess 51 therein, may be deformed due to excessive forces on the spindle 50.
It will be readily appreciated that only one bolt 53, or more than two bolts 53, may also be provided to fix the spindle 50 to the damper shaft 32 as long as the bolt(s) 53 is/are offset with respect to the rotation axis 38 of the damper shaft 32 and thus transfer(s) a significant part of the rotation of the damper shaft 32 to the spindle 50.
In the illustrated embodiments, the bolts 53 are bolted in a direction that is substantially parallel to the rotation axis 38 of the damper shaft, but it will be appreciated that other orientations of the bolts 53 are also possible. For example, the bolts 53 could be angled with respect to the damper shaft 32.
In the illustrated embodiments, the spindle 50 has the overall shape of a cup that is filled by the end 52 of the damper shaft 32. Specifically, the spindle 50 does not extend beyond the bolts 53, but rather the first threaded portion 55 is provided between the bolts 53 and the base element 46. In particular, the spindle 50 has a length L and the recess 51 has a depth D, both measured in the direction of the rotation axis 38 of the damper shaft 32 (as illustrated in Figure 5B), with the depth D comprising at least 50%, preferably at least 60% and more preferably at least 70% of the length L of the spindle 50. This configuration further enhances the overall strength of the spindle 50 and thus its durability.
As shown in Figures 1A and 1B, the hydraulic damper mechanism comprises a one-way valve 58 which allows the hydraulic fluid to flow from the low pressure compartment 43 of the cylinder cavity 40 to the high pressure compartment 42 thereof when the closure member 1 is opened. The opening movement of the closure member 1 is therefore not damped or at least to a smaller extent than the closing movement. In the illustrated embodiments, this one-way valve 58 is provided in the piston 41.
To achieve the damping action upon closing of the closure member 1 by the energy storing mechanism, at least one restricted fluid passage is provided between the two compartments 42, 43 of the cylinder cavity 40. One restricted fluid passage is formed by a channel 59 connecting, in all the possible positions of the piston 41, i.e. in all positions between its two extreme positions, the low pressure compartment 43 with the high pressure compartment 42 thereof. This channel 59 is provided with an adjustable valve 60, in particular a needle valve, so that the flow of hydraulic liquid through this channel 59 can be controlled.
The channel 59 could be provided in the cylindrical wall of the fixed hinge member 4, but, in the illustrated embodiments, this channel 59 is provided in a tubular member 61 that is integrally formed with the oil cap 39 at and end of the cylinder cavity 40 that is closed off by a first end cap 87. The tubular member 38 projects into the cylinder cavity 40 in the longitudinal direction 11 thereof. The needle of the adjustable valve 60 is screwed through an opening in the oil cap 39 into the tubular member 61 so that the adjustable valve 60 is adjustable from the outside upon removal of the first end cap 87.
The channel 59 in the tubular member 61 has a first opening 62 ending above the piston 41 in the low pressure compartment 43 of the cylinder cavity 40 and two second openings 63 ending below the piston 41 in the high pressure compartment 42 of the cylinder cavity 40.
The tubular member 61 further comprises a second channel 64 that has a first opening 65 about midway of the tubular member 61 and the two second openings 63 ending below the piston 41. When the piston 41 approaches its most downward extreme position, hydraulic fluid can flow along the second channel 64 from the high pressure compartment 42 of the cylinder cavity 40 to the low pressure compartment 43 thereof. As such, the second channel 64 forms a by-pass which causes an increase of the closing speed at the end of the closing movement, i.e. a final snap, to ensure that the closure member 1 is reliably closed. A second adjustable valve 66, in particular a needle valve, is provided so that the flow of hydraulic liquid through the channel 64 can be controlled to control the closing speed of the closure member 1 during the final snap.
The operation of the energy storing mechanism and the damper mechanism will be explained with respect to Figures 2A to 2D for a right-handed closure member 1 and with respect to Figures 3A to 3D for a left-handed closure member 1.
Figures 2A and 3A show a cross-sectional view of a right-handed and a left-handed closure member 1 respectively when it is halfway opened, e.g. when the closure member 1 has been rotated approximately 90° with respect to the support 2. When comparing with Figures 1A and 1B respectively, it is clear that the first actuation member 29 has remained stationary, while the second actuation member 30 has rotated over 90° thereby storing energy in the torsion spring 31. The damper shaft 32 has transferred the same rotation to the damping mechanism causing the piston 41 to move towards the damper shaft 32 as indicated by the dashed arrow. As the cylinder cavity 40 is filled with hydraulic fluid, the motion of the piston 41 results in a motion of the hydraulic fluid (indicated by the full arrow) across the one-way valve 58 from the low pressure compartment 43 to the high pressure compartment 42. It will be appreciated that the hydraulic fluid may also pass to some extent via the restricted fluid passage formed by channel 59. These motions continue until the closure member 1 is fully opened over 180° as illustrated in Figures 2B and 3B respectively.
Figures 2C and 3C illustrate the fully opened position of a right-handed and a left-handed closure member 1 respectively. The energy that was stored in the spring 31 is now restored to close the closure member 1. Specifically, the spring 31 urges the second actuation member 30 to move relative to the first actuation member 29. Because the second actuation member 30 is fixed to the damper shaft 32 and the moveable hinge member 5, these are also urged to rotate. The damper shaft 32 transfers this rotation to the piston 41 which is now moved away from the damper shaft 32 as indicated by the dashed arrow. The one-way valve 58 is now shut and the hydraulic fluid is forced through the restricted fluid passage formed by channel 59 in the tubular member 61. This restricted flow thus damps the closing movement. These motions continue as illustrated in Figures 2D and 3D which show the closure member 1 half closed, e.g. rotated over approximately 90° degrees. It is clear from Figures 2D and 3D that when the piston 41 continues to move away from the damper shaft 32, the first opening 65 of the second channel 64 in the tubular member 61 will not be blocked by the piston 41 anymore allowing hydraulic fluid to flow from the high pressure compartment 42 to the low pressure compartment 43 to decrease the damping to reliably close the closure member 1.
The hinge described above is mainly used outdoors where large temperature variations are not uncommon. For example, summer temperatures up to 70°C when the hinge is exposed to sunlight and winter temperatures below -30°C are not uncommon, i.e. temperature variations up to and possibly even exceeding 100°C are possible. Moreover, there are also daily temperature variations between night and day which can easily exceed 30°C when the hinge is subjected to direct sunshine. These temperature variations cause expansion, and also contraction, of the hydraulic fluid, which could affect the operation of the damping mechanism. In particular, the expansion due to temperature variations can be up to 1% of the volume of hydraulic fluid for a temperature variation of 10°C, depending on the expansion coefficient of the hydraulic fluid. As such, an expansion of, for example, up to 3 cc for a temperature difference of 50°C is possible.
To counter this expansion, a small amount of gas such as air could be provided in the hydraulic fluid itself. However, it has been found that this gas may interfere with the good working of the hinge, especially when gas bubbles, or an emulsion of the gas in the hydraulic fluid, pass through the restricted flow passage and provides a smaller damping effect than pure, i.e. gas-free, hydraulic fluid which affects the smooth closing movement of the closure member 1. Consequently, the hydraulic fluid is preferably free of gas bells or bubbles.
As used herein, the hydraulic fluid is considered to be free of gas bells or bubbles when the volume of gas entrained in the hydraulic fluid, for example in the form of bells, bubbles or an emulsion, is below 1,5%, preferably below 1%, more preferably below 0,5%, advantageously below 0,1% and more advantageously below 0,05% of the total volume of hydraulic fluid. As this skilled person knows, the volume of gas entrained in the hydraulic fluid may be determined by measuring the decrease in volume of the hydraulic fluid due to an increase in pressure, i.e. measuring the adiabatic bulk modulus of the hydraulic fluid at various pressures. For a hydraulic fluid without entrained gas, the adiabatic bulk modulus is constant irrespective of the pressure, while, for a hydraulic fluid with entrained gas, the adiabatic bulk modulus only becomes constant after a threshold pressure has been exceeded, which threshold pressure corresponds to the pressure when all entrained gas has been compressed. As such, a measure of the volume of entrained gas in the hydraulic fluid is the difference in volume between the hydraulic fluid under atmospheric pressure and the hydraulic fluid under the threshold pressure. The volume of entrained gas is then about equal, but not exceeding, this difference in volume.
In the hinge illustrated in the drawings, expansion of the hydraulic fluid is therefore countered by means of an expansion channel 69 with a moveable plunger 70 therein as shown in Figures 7A, 7B, 8A and 8B. The plunger 70 divides the expansion channel 69 into a first compartment 71 having a first volume that is in fluid communication with the cylinder cavity 40 via a fluid channel 75 and a second compartment 72 having a second volume. The plunger 70 has a ring-shaped seal 73 on its outside to prevent leaks between the hydraulic fluid and the pressure relief compartments 71, 72. As such, the plunger 70 acts a moveable seal. It will be readily appreciated that multiple ring-shaped seals 73 may also be provided. When the hinge is exposed to a temperature increase, the volume of the hydraulic fluid increases pushing the plunger 70 deeper into the expansion channel 69 and when the volume of the hydraulic fluid decreases, the plunger 70 is sucked back to close the expansion channel 69.
Turning to Figures 6A and 6B the expansion channel 69 is provided adjacent to the fixed barrel 6, i.e. it is formed as a part of the fixed leaf 8. In an alternative embodiment, illustrated in Figures 7A and 7B, the expansion channel 69 is provided in the damper shaft 32. In both embodiments, the first compartment 71 is in fluid communication with the low pressure compartment 43 of the cylinder cavity 40. As such, the plunger 70 is not exposed to the high pressures that result from the normal operation of the damping mechanism. This is advantageous as, exposing the first compartment 71 to the high pressure compartment 42 would affect the closing movement of the closure member 1, i.e. the hydraulic fluid would not only flow via the channel 59 but would also enter the first compartment 71 by displacing the plunger 70.
In the illustrated embodiments, the second compartment 72 is also provided with a biasing member formed by a compression spring 74 and an end cap 76 that seals off the expansion channel 69 from the outside, by two sealing rings 89, and that urges the plunger 70 towards the fluid channel 75. The effect of this spring 74 is that the hydraulic fluid is pressurised so that negative pressures in the hydraulic fluid are alleviated. Specifically, the hydraulic fluid is usually added at room temperature, e.g. near 20°C. When the hinge is exposed to temperatures down to -30°C a negative pressure would occur in the hydraulic fluid in the absence of the compression spring 74. When the hinge is first exposed to temperatures up to 70°C., and then cooled down to a low temperature, the increased friction between the ring-shaped seal 73 and the expansion channel 69 (as a result of the fact that the seal becomes less flexible at lower temperatures) could result, in absence of the compression spring 74, in an additional negative pressure in the hydraulic fluid which could result in air getting sucked into the cylinder cavity 40 via the seal 49 around the damper shaft 32 or via the seal 73 on the plunger 70. This problem is solved by the compression spring which pressurizes the hydraulic fluid, even at low temperatures, so that any risk of air being sucked into the cylinder cavity being avoided.
In the illustrated embodiments, the pressure relief compartment 76 is filled, besides the compression spring 74, with air and is closed off by the end cap 76. When, the end cap 76 provides an airtight seal, the gas in the pressure relief compartment 76 could be pressurised to assist or replace the compression spring 74.
The volume of the expansion channel 69 and the first and second volumes are mainly determined in function of the expected increase in volume of the hydraulic fluid. In the illustrated embodiments, the first volume is preferably at least 1.5 cc, more preferably at least 2 cc, advantageously at least 2.5 cc and more advantageously at least 3 cc when the plunger 70 is pushed as far back as possible into the expansion channel 69, i.e. when the first volume is maximal. The maximal second volume is preferably substantially the same as the maximal first volume to provide enough space for the compression spring 74.
It will be readily appreciated that, in other embodiments, the first hinge member 4 may be fixed to the closure member 1 and the second hinge member 5 may be fixed to the support 2 without modifying the internal structure of the hinge as described above.
As described above, the actuator may also be provided as a separate device that can be retrofitted onto an existing hinged closure member 1 or that can be used with separate hinges. In particular, the actuator of the present invention can be constructed in a same way as the actuator disclosed in EP-B-2356304 . The actuator disclosed therein is mounted in a vertical position on a support 2 onto which the closure member 1 is hinged. At the top it has a rotating arm which is slidably mounted on the hinged closure member 1 so that when the hinged closure member 1 is opened or closed, a damper shaft also rotates within the actuator. Such a closing device is offered for sale by the applicant under the names "Verticlose" and "Samson". It will be readily appreciated that either one of the spring mechanism and the damping mechanism in EP-B-2356304 may be substituted by the energy storing mechanism and the damping mechanism described above. Moreover, an expansion channel as described above may also be combined with the damping mechanism in EP-B-2356304 .
Although aspects of the present disclosure have been described with respect to specific embodiments, it will be readily appreciated that these aspects may be implemented in other forms within the scope of the claims.

Claims

A hydraulically damped actuator for closing a closure member (1) hinged to a support (2), the actuator comprising:
- an energy storing mechanism configured for storing energy when said closure member (1) is being opened and for restoring said energy to effect closure of said closure member (1), the energy storing mechanism comprising a first and a second actuation member (29, 30) and a spring mechanism (31) arranged between both actuation members (29, 30), the actuation members (29, 30) being rotatable with respect to one another around a rotation axis (38) in a first mutual direction to store said energy in said spring mechanism (31) and in a second mutual direction, which is opposite to said first mutual direction, to restore said energy;

- a damping mechanism configured for damping a closing movement of said closure member (1), the damping mechanism comprising:
- a closed cylinder cavity (40) that has a longitudinal direction (10) and is filled with a volume of hydraulic fluid;

- a damper shaft (32) having a first end extending into the cylinder cavity (40), the damper shaft (32) being rotatable around the rotation axis (38) that extends substantially in said longitudinal direction (10) and being configured to transfer the opening and closing movement of the closure member (1) to the damping mechanism;

- a piston (41) within said cylinder cavity (40) so as to divide the cylinder cavity (40) into a high pressure compartment (42) and a low pressure compartment (43), the piston (41) being operatively coupled to said damper shaft (32) to be movable between two extreme positions in said longitudinal direction (10);

- a one-way valve (58) allowing fluid flow from the low pressure compartment (43) to the high pressure compartment (42) when said closure member (1) is being opened; and

- at least one restricted fluid passage (59) between the compartments (42, 43);

- a pressure compensation mechanism for compensating changes of the volume of said hydraulic fluid upon temperature variations thereof; and

- a first and a second connection element, the first connection element being configured to connect the actuator to the support (2) and the second connection element being configured to connect the actuator to the closure member (1), the energy storing mechanism being operatively connected with said first connection element and said second connection element and the damping mechanism being operatively connected with said first connection element and said second connection element,
characterised in that
said pressure compensation mechanism comprises an expansion channel (69) with a plunger (70) that fits into the expansion channel (69) and is slidably received therein, the plunger (70) dividing the expansion channel (69) into a first compartment (71) which is in fluid communication with said cylinder cavity (40) and a second compartment (72) that is sealed off from the first compartment (71) by said plunger (70), the second compartment (72) allowing the plunger (70) to slide within the expansion channel (69) to compensate said changes of the volume of the hydraulic fluid.
An actuator according to claim 1, characterised in that said second compartment (72) comprises a biasing member urging the plunger (70) towards said second compartment (72) to pressurize the hydraulic fluid.
An actuator according to claim 2, characterised in that said biasing member comprises a compression spring (74).
An actuator according to any one of the preceding claims, characterised in that the plunger (70) is provided with a seal (73) that engages an inner surface of the expansion channel (69).
An actuator according to any one of the preceding claims, characterised in that said first compartment (71) of the expansion channel (69) is part of said low pressure compartment (43).
An actuator according to any one of the preceding claims, characterised in that the hydraulic fluid is free of gas bells or bubbles.
An actuator according to any one of the preceding claims, characterised in that said second compartment (72) of the expansion channel (69) is filled with a gas, in particular with air.
An actuator according to any one of the preceding claims, characterised in that the expansion channel (69) has a cylindrical cross-section.
An actuator according to any one of the preceding claims, characterised in that said first end has an end face (68) and a portion (52) with a non-circular cross-section, the damping mechanism comprising a spindle (50) made of a synthetic material and having a recess (51) with a non-circular cross-section fitting onto said portion (52) of the damper shaft (32), the spindle (50) being fixed onto said first end of the damper shaft (32) and having an outer threaded portion (55) with a screw axis which coincides with said rotation axis (38), the piston (41) having an inner threaded portion (56) with a screw axis which also coincides with said rotation axis (38), the outer threaded portion (55) of the spindle (50) on the damper shaft (32) being in engagement with the inner threaded portion (56) of the piston (41) to operatively couple the piston (41) to said damper shaft (32).
An actuator according to claim 9, characterised in that said recess (51) in the spindle (50) has a bottom (86) which engages said end face (68) of the damper shaft (32), the spindle (50) being fixed to the damper shaft (32) by at least one bolt (53) that is bolted through the bottom (86) of the spindle (50) into the end face (68) of the damper shaft (32), the at least one bolt (53) having a head which is sunk into the bottom (86) of the spindle (50) and being offset with respect to said rotation axis (38) to irrotatably fasten the spindle (50) to the damper shaft (32).
An actuator according to any one of the preceding claims, characterised in that the expansion channel (69) is formed by a cavity inside the damper shaft (32).
An actuator according to any one of the claims 1 to 10, characterised in that the expansion channel (69) is formed by a cavity adjacent to said cylinder cavity (40).
An actuator according to any one of the preceding claims, characterised in that the actuator is configured to be mounted with said longitudinal direction (10) having a near vertical orientation.
A hydraulically damped, self-closing hinge for hinging a closure member (1) to a support (2), the hinge comprising:
- a first hinge member (4) comprising a first barrel (6) and a first leaf (8) fixed to said first barrel (6) and configured to be fixed to one of: the support (2) and the closure member (1);

- a second hinge member (5) pivotably mounted on the first hinge member (4) through the intermediary of a first and a second rolling bearing (14)(13, 14), the second hinge member (5) comprising a second barrel (7) and a second leaf (9) fixed to said second barrel (7) and configured to be fixed to the other one of: the support (2) and the closure member (1); and
an actuator according to any one of the preceding claims, the first connection element being formed by one of: the first and the second hinge member (4, 5) and the second connection element being formed by the other one of: the first and the second hinge member (4, 5).
A hinge according to claim 14, characterised in that said first barrel (6) has a main body and a hollow shaft (12) extending from said main body with the damper shaft (32) extending through the hollow shaft (12), the second barrel (7) being pivotably mounted on said hollow shaft (12) through the intermediary of said rolling bearings (13, 14) each having an inner race (19, 20) and an outer race (21, 22), the inner races (19, 20) of said rolling bearings (13, 14) radially engaging an outer surface of said hollow shaft (12), the outer races (21, 22) of said rolling bearings (13, 14) radially engaging an inner surface of said second barrel (7), the inner race (19) of the first rolling bearing (13) being axially engaged by a first abutment (23) on said first barrel (6), the inner race (20) of the second rolling bearing (14) being axially engaged by a second abutment (24) fixed onto said hollow shaft (12), the outer race (21) of the first rolling bearing (13) being axially engaged by a third abutment (25) on the inner surface of said second barrel (7), the outer race (22) of the second rolling bearing (14) being axially engaged by a fourth abutment (26) on the inner surface of said second barrel (7).