A GATE CLOSER AND A CLOSURE SYSTEM COMPRISING THE SAME

Abstract

 A gate closer comprising an electromotor with an output shaft and a driver to urge a closure member to close. Disposed therebetween is a torque limiter comprising: a cylindrical base (11); a washer (13) disposed in an annular recess (65) of the cylindrical base and rotationally locked thereto; a first annular friction disk (14) disposed adjacent the washer and rotationally locked thereto; a second annular friction disk (15) disposed adjacent the first annular friction disk and rotationally locked to the driver; and a biasing member (12) disposed in the annular recess and urging the annular friction disks towards one another. The annular friction disks comprises a plurality of inclined surfaces on the side facing one another which are configured to transfer a rotational motion.

Description

Technical field

[0001] The present invention generally relates to a gate closer for closing a closure system having a support and a closure member that are hingedly connected to each other. The present invention further relates to a closure system comprising the gate closer.

Background art

[0002] Various types of gate closers are known in the art, for example spring-biased gate closers as disclosed in WO 2012/103572; hydraulically damped spring-biased gate closers as disclosed in WO 2018/228729; and motorized gate closers as disclosed in WO 2019/048359. The present invention is generally related to gate closers of the latter kind which are operated by an electromotor.

[0003] The gate closer disclosed in WO 2019/048359 comprises: an elongated housing configured to be mounted against a support, the elongated housing extending in a longitudinal direction between a first end and a second end; an electromotor mounted in the housing, the electromotor having an output shaft near the first end of the elongated housing and which is rotatable around said longitudinal direction in a first rotational direction upon activation of the electromotor; and a driver operatively connected to the output shaft (i.e. by being connected to the eyebolt hinge), the driver being configured to urge the closure member to its closed position upon rotation of the output shaft in said first rotational direction.

[0004] In the gate closer of WO 2019/048359, the driver is directly fixed on the output shaft of the electromotor. Whilst this provides a very compact design, there is a risk of damaging the electromotor when the gate undergoes a sudden directional change. For example, when the gate is closing, a user may appear who wishes to pass through the gateway and thus pushes against the closing gate. This force requires a very sudden reversal of the electromotor rotation direction. Such sudden reversals are a known cause of damage to the electromotor.

[0005] In order to address this issue, it is customary to position a torque limiter between the output shaft and the driver as disclosed in FR 2751690 and FR 2776008. Specific constructions of torque limiters for door closers are disclosed in FR 2508530 and GB 2236142.

[0006] FR 2508530 discloses on a slip clutch involving two annular flat rings that are forced against one another by an elastic ring. A drawback of such a slip clutch is wear over time of the rings. Moreover, also the elastic ring suffers from wear and creep over time which reduces the force exerted onto the rings. This in turn causes more slip and a reduced torque on the gate. FR 2508530 further discloses the use of a sensor assembly to determine an angular position of the slip disks relative to one another which allows the electromotor to return to a calibrated position after the slip clutch has slipped due to excessive torque.

[0007] GB 2236142 discloses providing a V-shaped groove in the free end of the output shaft and an annular plate having a wedge-section transverse projection that is biased into engagement with the V-shaped groove by a disc spring. A drawback of such a wedge-section transverse projection is that, if the annular plate is disengaged due to an excessive torque, the force exerted by the disc spring on the annular plate is borne solely by the projection. This creates a very large pressure that can damage the projection and could even lead to such extensive damage that the annular plate can no longer engage with the V-shaped groove in the output shaft. Furthermore, even when engaged, the force generated by the electromotor is solely transferred from the output shaft to the annular plate by the projection in the V-shaped groove. Again this leads to a very large pressure that can damage the projection.

Disclosure of the invention

[0008] It is an aim of the present invention to provide an improved gate closer.

[0009] To his aim the gate closer according to the invention comprises a torque limiter disposed between the output shaft and the driver, the torque limiter comprising: a cylindrical base positioned at its first end of the elongated housing and being fixed to the output shaft. The cylindrical base has: a first side facing towards the elongated housing; a second side opposite the first side in said longitudinal direction; a circumferential wall extending between the first side and the second side; and an annular recess with an open side facing away from the elongated housing. The torque limiter further comprises: a first annular friction disk disposed in the annular recess of the cylindrical base and rotationally locked with respect to the cylindrical base, the first annular friction disk comprising a plurality of first inclined surfaces on the side of the first annular friction disk facing away from the cylindrical base; a second annular friction disk disposed adjacent the first annular friction disk and rotationally locked to the driver, the second annular friction disk comprising a plurality of second inclined surfaces on the side of the second annular friction disk facing the first annular friction disk, said plurality of first and second inclined surfaces being configured to transfer a rotational motion of the first annular friction disk to the second annular friction disk; and a biasing member disposed in the annular recess of the base, the biasing member urging the first annular friction disk towards the second annular friction disk thereby engaging said plurality of first and second inclined surfaces with one another.

[0010] Firstly, the provision of a torque limiter already improves upon the gate closer disclosed in WO 2019/048359 as damage to the electromotor due to a sudden change is rotation of the gate is avoided. More specifically, in case of a sudden change in direction (e.g. due to user intervention), a high amount of torque (typically exceeding 200 to 300 N·m) is transmitted from the gate to the torque limiter. Such high torque causes the annular friction disks to disengage against the force exerted by the biasing member. The first annular friction disk rotationally locked to the output shaft of the electromotor is thus free to rotate thus allowing the electromotor sufficient time to reverse direction.

[0011] Secondly, the torque limiter according to the present invention is in itself also an improvement over the known torque limiters. Since the annular friction disks each comprise multiple inclined surfaces, the force to be transferred while the disks are engaged is divided over a large surface area thus avoiding any local high pressures which could damage the friction disks. This in turn allows to keep the disks engaged for higher torque values (e.g. exceeding 40 or 50 N·m or even exceeding 100 N·m). This is beneficial since higher torque values enable to reliably close large gates (e.g. up to 2 m in length) and/or heavy gates even when high additional loads are exerted on the gate (e.g. wind pressure).

[0012] In an embodiment of the present invention the annular friction disks interlock with one another only in a single angular position of the first annular friction disk with respect to the second annular friction disk. Having annular friction disks which interlock in only a single angular position avoids the need for additional sensors to detect the angular position of the disks relative to one another. More specifically, the driver of the gate closer has a fixed unique position with respect to the output shaft. When the disks become disengaged, the electromotor can finish its preprogrammed action to close (or open) the gate. Afterwards, the electromotor becomes active again (or stays active) until the disks interlock again with the driver of the gate closer in the fixed unique position with respect to the output shaft.

[0013] In an embodiment of the present invention the first annular friction disk is slidable with respect to the cylindrical base along said longitudinal direction between an engaging position in which said plurality of first and second inclined surfaces are engaged with one another and a releasing position in which said plurality of first and second inclined surfaces are not engaged with one another. In order to disengage the annular friction disks a measure of relative displacement in the longitudinal direction is required. Whilst this can be provided by having the driver as a whole slidable with respect to the cylindrical base or by having the second annular friction disk slidable with respect to the driver, it is preferred that this is done by having the first annular friction disk is slidable with respect to the cylindrical base. This allows to have a compact (in particular thin) driver, which would be the case if the second annular friction disk were slidable with respect to the driver, without having a different exterior view, which would be the case if the driver were slidable with respect to the cylindrical base.

[0014] In an embodiment of the present invention the gate closer further comprises a washer disposed in the annular recess of the cylindrical base and interposed between the first annular friction disk and the biasing member, the washer being rotationally locked to the cylindrical base, the first annular friction disk preferably being rotationally locked to the washer, the washer preferably having a thickness of at least 1,5 mm and more preferably of at least 2 mm. In this embodiment the torque limiter further comprises a washer disposed between the cylindrical base which is rotationally locked to the output shaft and the first annular friction disk. Both the washer and the first annular friction disk are rotationally locked with one another and with the cylindrical base. This washer has a few advantages. It allows positioning the biasing member in the annular recess of the cylindrical base thus avoiding having to place the biasing member on the driver side of the gate closer which would necessarily lead to a less compact (in particular thin) driver. Furthermore, as described further, it allows the first annular friction disk to be manufactured from a plastic material which is advantageous. The minimum thickness is chosen so as to increase the contact surface area with the cylindrical base to reduce local pressure generated by the torque since a too high pressure could damage the cylindrical base or the washer. Furthermore, such thickness provides a sufficiently rigid washer that evenly distributes the force exerted by the biasing member, which force may not be evenly exerted on the washer.

[0015] In a preferred embodiment of the present invention the circumferential wall comprises a crenelated region at the second side and that the washer comprises a crenelated outer circumference which interlocks with the crenelated region of the circumferential wall thereby rotationally locking the washer to the cylindrical base. The crenelated region particularly extends over substantially the entire circumference of the circumferential wall, the crenelated region preferably comprising uniformly distributed merlons with at least six, particularly at least eight, merlons being preferred.

[0016] The use of crenelated regions to rotationally lock the washer to the cylindrical base is advantageous since the mutual engagement is located on a most radially outwards position. As such, the torque-based forces are minimized with respect to a more central engagement. Reducing the forces in turn lowers the local pressure which, as described above, is desirable as high pressures can cause damage. This effect is further enhanced by uniformly distributing the merlons (i.e. uniformly distributed the engagement surfaces) and by increasing the number of merlons which increase tot surface area over which the force is distributed. Furthermore, the use of crenels and merlons allows the washer to slide longitudinally with respect to the cylindrical base. As such, when the annular friction disks disengage, the first friction disk has space to slide thus allowing the second friction disk to remain stationary with respect to the driver. This also contributes to providing a compact (in particular thin) driver.

[0017] In a more preferred embodiment of the present invention the crenelated outer circumference comprises a further merlon in each crenel, each further merlon engaging a free end of an inner sleeve of the cylindrical base when the biasing member is compressed. In this embodiment, when the annular friction disks disengage, a bottom wall delimiting each crenel in the circumferential wall together with a part of the inner sleeve forms an abutment surface against which the further merlons and the merlons creating the crenels on the washer abut. The further merlons in essence add to the total abutment surface area thus again reducing pressure. Furthermore, this also avoids the need for sharp interior angles in each crenel which tend to lead to manufacturing difficulties.

[0018] In a preferred embodiment according to the present invention the washer comprises a plurality of first interlocking means provided on the side of the washer facing away from the elongated housing and the first annular friction disk comprises a plurality of second interlocking means provided on the side of the first annular friction disk facing the washer, said plurality of first and second interlocking means rotationally locking the first annular friction disk to the washer; and/or the second annular friction disk comprises a plurality of third interlocking means provided on the side of the second annular friction disk facing away from the elongated housing and the driver comprises a plurality of fourth interlocking means, said plurality of third and fourth interlocking means rotationally locking the second annular friction disk to the driver. Preferably, the first interlocking means are formed by a plurality of recesses, particularly circular recesses, and the second interlocking means are formed by a plurality of corresponding protrusions, particularly circular protrusions; and/or the fourth interlocking means are formed by a plurality of recesses, particularly circular recesses, and the third interlocking means are formed by a plurality of corresponding protrusions, particularly circular protrusions.

[0019] In this embodiment, the interlocking means between the washer and the first annular friction ring on the one hand and the interlocking means between the driver and the second annular friction ring are formed on the surfaces facing one another. This not only provides sufficient surface area to position the interlocking means, it also avoids that such means would increase a radial dimension of the elements involved which would lead to an overall increase in the dimension of the gate closer.

[0020] Furthermore, using a plurality of recesses and protrusions increase the contact surface area between the respective elements. This in turn, as stated above, reduces the local pressure which is desirable. It is further advantageous to provide the protrusions on the friction disks and the recesses in the other elements as doing otherwise would weaken the friction disks. Since the friction disks are, for reasons described below, preferably plastic, it is desirable not to weaken these. Whereas the driver and/or washer can be more easily manufactured from stronger materials, e.g. metal, where a local weakening due to a recess is more easily accounted for.

[0021] In a more preferred embodiment of the present invention at least some of the protrusions comprise a circumferential ridge with an inner reinforcing rib, the inner reinforcing rib extending tangentially with respect to a hypothetical circle having a center coinciding with a center of a respective annular friction disk. The reinforcing rib, especially when oriented tangentially as the torque applied causes a tangential force, again reduces the local pressure on each circumferential ridge. More specifically, a part of the force is transmitted across the circumferential ridge to (when viewed in the direction of rotation) the rear wall of the ridge which would otherwise be substantially unloaded.

[0022] In a more preferred embodiment of the present invention the first and second interlocking means and/or the third and fourth interlocking means each comprise N recesses and corresponding protrusions, N being a natural number larger than 3, wherein (N-1) of the recesses and corresponding protrusions are identical to one another and one of the recesses and corresponding protrusions is different. This provides a convenient way to provide a unique placement of the first annular friction disk with respect to the washer and/or of the second annular friction disk with respect to the driver.

[0023] In a preferred embodiment of the present invention the washer has a non-circular central opening disposed on a corresponding non-cylindrical shaft of the cylindrical base. This creates a further engagement surface between the washer and the cylindrical base for transferring torque-generated forces. As stated above, increasing the total surface area for torque transfer is beneficial to reduce local pressure as much as possible. Furthermore, this also causes a single unique position of the washer with respect to the cylindrical base.

[0024] In an embodiment of the present invention the first annular friction disk comprises a plurality of depressed areas and a plurality of heightened areas with respect to a hypothetical flat disk, the plurality of first inclined surfaces being formed between adjacent ones of the depressed and heightened areas, and the second annular friction disk comprises a plurality of depressed areas and a plurality of heightened areas with respect to a hypothetical flat disk, the plurality of second inclined surfaces being formed between adjacent ones of the depressed and heightened areas. Preferably, the depressed and heightened areas on the annular friction disks interlock with one another only in a single angular position of the first annular friction disk with respect to the second annular friction disk. Providing different levels (i.e. heightened and depressed) on the annular friction disks is a convenient way to create a plurality of inclined surfaces. Moreover, having annular friction disks which interlock in only a single angular position avoids the need for additional sensors to detect the angular position of the disks relative to one another as described above.

[0025] In a preferred embodiment of the present invention the depressed and heightened areas on each annular friction disk form at least an inner ring and an outer ring which are concentric with one another, wherein, preferably, the inner ring has J heightened areas, J being a natural number larger than one, and the outer ring has K heightened areas, K being a natural number larger than one, J and K being relative prime numbers. The use of two rings is allows to form a unique engagement position. This can be achieved by having J and K number of heightened areas on respective ones of those rings, where J and K are relative prime numbers. It could also be achieved by including depressed and heightened areas with mutually differing areas but this may increase the risk of non-uniform distribution of the biasing force when the annular friction disks are disengaged.

[0026] In a more preferred embodiment of the present invention the depressed and heightened areas on the annular friction disks interlock with one another only in a single angular position of the first annular friction disk with respect to the second annular friction disk, and, when the annular friction disks are not in said single angular position: the heightened areas of the first ring of the first annular friction disk at least partially engage the heightened areas of the first ring of the second annular friction disk and/or the heightened areas of the third ring of the first annular friction disk at least partially engage the heightened areas of the third ring of the second annular friction disk, the engagements being substantially uniformly distributed over the circumference of a respective ring; and/or the heightened areas of the first ring of the first annular friction disk at least partially engage the heightened areas of the first ring of the second annular friction disk and/or the heightened areas of the third ring of the first annular friction disk at least partially engage the heightened areas of the third ring of the second annular friction disk, the total engaged surface area being at least 20%, particularly at least 30%, more particularly at least 35%, of a total surface area of the heightened areas on the first ring and the third ring of one of the annular friction disks.

[0027] When the annular friction disks are disengaged, the biasing member exerts a large force on the rings to urge these together. In order to avoid local high pressures, it is advantageous to distribute this biasing force across as large a surface area as possible. It is also advantageous to distribute this biasing force evenly over the rings to avoid torsional effects.

[0028] In a more preferred embodiment of the present invention the depressed and heightened areas on each annular friction disk form at least one additional ring concentric with the inner ring and the outer ring, said at least one additional ring preferably comprising a substantially continuous regular zigzag pattern, said at least one additional ring preferably comprising at least twenty heightened areas. The use of three (or more) rings is advantageous as one or more rings can be used to form many inclined surfaces for pressure reduction while engaged, while two rings can be used to form a unique engagement position. The placement of the additional ring with respect to the inner and outer ring is a matter of production and/or design choice.

[0029] In a more preferred embodiment of the present invention the inner or outer ring is substantially symmetric with respect to a hypothetical plane which bisects one of the heightened areas. The other one of the inner and outer ring is then advantageously non symmetric with respect to said plane to provide the unique interlocking angular position.

[0030] In a more preferred embodiment of the present invention the heightened and depressed areas are substantially uniformly spread over each ring. This aids in distributing the biasing force evenly over the rings of the friction disks.

[0031] In an embodiment of the present invention the driver comprises a threaded hole facing the elongated housing and the cylindrical base comprises a through-opening aligned with said threaded hole, the driver being fixed to the cylindrical base by a fixation bolt which is placed through said through-opening into said threaded hole. Preferably, the cylindrical base and the driver substantially do not contact one another, the cylindrical base particularly comprising a first abutment surface and the fixation bolt particularly comprising a second abutment surface which abut against one another preventing a further tightening of said fixation bolt. The specific way of attaching the driver to the base is not visible from the exterior of the gate closer. The fixation bolt is also not accessible in the mounted gate closer which improves safety and anti-tamper properties as a person cannot simply unfasten the driver from the gate closer. Furthermore, the abutment surfaces prevent a further tightening of said fixation bolt. In other words, the abutment surfaces cause a stop for the fixation bolt and thus determine the relative position of the driver with respect to the cylindrical base. This position is advantageously determined so as to provide a minimal spacing between adjacent surfaces of the driver and the cylindrical base, which spacing avoids that these surfaces slide along one another and cause undesired friction.

[0032] In an embodiment of the present invention the biasing member comprises a stack of disc springs. The stack of disc springs is easy to position in the annular recess in the cylindrical base. Moreover, the number can be increased or decreased depending on the desired biasing force.

[0033] In an embodiment of the present invention the cylindrical base is manufactured from metal, preferably aluminum. Although many materials could be used aluminum is preferred as it lends itself for outdoor use due to its anti-corrosive properties. It is also light-weight and high strength.

[0034] In a preferred embodiment of the present invention the washer is manufactured from metal, preferably stainless steel. As the washer is required to transfer all forces from the motor to the first annular friction disk, it is preferred to a use a very high strength metal (e.g. stainless steel) to avoid distortion.

[0035] In an embodiment of the present invention the driver is manufactured from metal, preferably aluminum. Although many materials could be used aluminum is preferred as it lends itself for outdoor use due to its anti-corrosive properties. It is also light-weight and high strength.

[0036] In an embodiment of the present invention the annular friction disks are manufactured, in particular injection molded, from plastic. Firstly, injection molding allows to create the complex three-dimensional shape of the annular friction disks in an economical fashion. Secondly, the use of a plastic material is preferred over a metal material due to the stability of the friction coefficient. More specifically, the friction coefficient of metals is generally less stable in moist and oily environments when compared to a plastic material. Since the gate closer is meant for outdoor use, moisture is to be expected, a plastic material is preferred. Furthermore, each annular friction disk may also be manufactured from a different plastic material which may avoid contact welding which could occur when same material annular friction disks are used.

[0037] In an embodiment of the present invention the inclination of said plurality of first and second inclined surfaces decreases when moving radially outwards on the annular friction disks, an average inclination angle being preferably between 20 and 60 degrees, with particular lower limits of 30 degrees and 35 degrees, and with particular upper limits of 55 degrees and 50 degrees. The decreasing inclination angle ensures that the annular friction disks are slid away from one another over a same distance irrespective of the radial position. This would not be the case with a fixed angle as a rotation of 5 degrees would cause a higher height shift at a smaller radius when compared to a larger radius. As such, the inclined surfaces remain engaged with one another over the entire radial direction during the disengagement.

[0038] In an embodiment of the present invention the annular friction disks are manufactured from a material having a static coefficient of friction between 0,05 and 0,5, the static coefficient of friction being particularly at least 0,1 and more particularly at least 0,2, the static coefficient of friction being particularly at most 0,4, more particularly at most 0,3 and even more particularly at most 0,2.

[0039] In an embodiment of the present invention a biasing force of the biasing member is at least 2000 N, particularly at least 3000 N, in a rest position of the biasing member. Preferably, when the annular friction disks are disengaged, a biasing force of the biasing member is at least 4000 N, particularly at least 5000 N.

[0040] In an embodiment of the present invention the annular friction disks have an outer diameter comprised between 3 and 15 mm, with particular lower limits of 4 mm and 5 mm and with particular upper limits of 10 mm and 8 mm.

[0041] The values of the static coefficient of friction, the average inclination angle, and the biasing force are determined so as to keep the annular friction disks engaged up to a desired torque and to disengage these when the torque exceeds a desired threshold. The following is an overview of the forces acting on the annular friction disks:

• biasing force F_B; and
• torque force F_T = ^2τ/_d where τ is the torque and d is the average diameter of the annular friction disks; and
• friction force F_f = µF_N where µ is the static coefficient of friction and F_N is the normal force.

[0042] Using the inclination angle α of the inclined surface with respect to the longitudinal direction, the following equation is obtained:

which links the torque to the biasing force, the inclination angles and the average diameter of the annular friction disks. As the average diameter of the annular friction disks is mainly determined in relation to the elongated housing, there is limited room to vary this parameter. Moreover, it is preferably as large as possible to increase contact surface area between various elements. Another consideration is the slip torque which is experienced when the annular friction disks are disengaged. This is given by F_S = ^µdFB/₂.

[0043] In view of the above, the static coefficient of friction is a trade-off. On the one hand a high static coefficient of friction means being able to reduce the biasing member force which usually allows a smaller biasing member to be used thus leading to a compact gate closer. On the other hand, a low static coefficient of friction means that the slip torque which is experienced when the annular friction disks are disengaged is reduced thus making it easier to re-engage the annular friction disks.

[0044] In an embodiment of the present invention a biasing force of the biasing member, the inclination of said plurality of first and second inclined surfaces, and a static coefficient of friction of the annular friction disks are such that the annular friction disks disengage for a torque exceeding 400 N·m, preferably exceeding 300 N·m and more preferably exceeding 250 N·m.

[0045] In an embodiment of the present invention the inclination of said plurality of first and second inclined surfaces, and a static coefficient of friction of the annular friction disks are such that the annular friction disks remain engaged for a torque of up to at least 40 N·m, preferably at least 50 N·m, more preferably at least 60 N·m and most preferably at least 65 N·m. Furthermore, for larger and/or heavier gates, these parameters can also be set so that annular friction disks remain engaged for a torque of up to at least 100 N·m , preferably up to at least 120 N·m and more preferably up to at least 140 N·m.

[0046] In an embodiment of the present invention a biasing force of the biasing member and a static coefficient of friction of the annular friction disks are such that a slip torque is between 5 and 40 N·m, with particular lower limits of 8 N·m, 12 N·m and 15 N·m, and with particular upper limits of 35 N·m, 30 N·m and 25 N·m.

[0047] In an embodiment of the present invention the electromotor generates a torque of at most 200 N·m, preferably at most 180 N·m and more preferably at most 160 N·m. This avoids that the electromotor would itself disengage the annular friction disks.

[0048] The advantages of the embodiments described above are also achieved with a closure system having a support and a closure member that are connected to each other by at least one hinge, the closure system further comprising a gate closer as described above with the elongated housing mounted to the support and the driver engaging the closure member or said at least one hinge.

[0049] It will be appreciated that the elongated housing can be mounted on the outside surface of the support (e.g. as in WO 2019/048359) or alternatively that this can be mounted inside a hollow part of the support (e.g. as disclosed in figures 12A to 14B and 18A to 19B of WO 2018/228729). Furthermore, the driver can be directly coupled to the closure member (e.g. using a sliding rail as disclosed in figures 8 to 10C of WO 2018/228729) or can be coupled to the eyebolt hinge (e.g. as in WO 2019/048359 or as in figures 1A to 3B of WO 2018/228729).

[0050] It will be readily appreciated that, as will also become evident from the further description, that the above mentioned embodiments of the present invention (incl. preferred, more preferred, advantageous, more advantageous, alternative, etc. embodiments and/or other optionally indicated features) should not be limited to individual elements, but may be combined with one another to achieve even other embodiments than those already described, which embodiments may also be part of the present invention as defined in the appended claims

Brief description of the drawings

[0051] The invention will be further explained by means of the following description and the appended figures.

Figure 1 shows a perspective view of a closure system with a gate closer according to the present invention.

Figure 2 shows a perspective view of a gate closer according to the present invention.

Figure 3 shows a torque limiter used in a gate closer according to the present invention.

Figure 4 shows an exploded view of the torque limiter.

Figure 5A shows a bottom view of the driver of the gate closer.

Figures 5B and 5C show top and bottom views of the second annular friction disk.

Figures 5D and 5E show top and bottom views of the first annular friction disk.

Figure 5F shows a top view of the washer.

Figure 5G shows a top view of the cylindrical base.

Figure 6 shows a perspective view of the annular friction disks separated from one another.

Figure 7 shows a cross-section through the torque limiter.

Description of the invention

[0052] 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 drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the invention.

[0053] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms are interchangeable under appropriate circumstances and the embodiments of the invention can operate in other sequences than described or illustrated herein.

[0054] Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes. The terms so used are interchangeable under appropriate circumstances and the embodiments of the invention described herein can operate in other orientations than described or illustrated herein.

[0055] Furthermore, the various embodiments, although referred to as "preferred" are to be construed as exemplary manners in which the invention may be implemented rather than as limiting the scope of the invention.

[0056] The term "substantially" includes variations of +/- 10% or less, preferably +/-5% or less, more preferably +/-1% or less, and more preferably +/-0.1% or less, of the specified condition, in as far as the variations are applicable to function in the disclosed invention. It is to be understood that the term "substantially A" is intended to also include "A".

[0057] The invention generally relates to an electrically driver gate closer 3 for closing a closure system. The closure system (shown in figure 1) comprises a support 1, such as a wall or a post, and a moveable closure member 2, such as a gate, a door, or a window. The closure member 2 is fixed to the support 1 by means of hinges 4, in particular eyebolt hinges, for example as disclosed in EP 1528202, EP 2778331 or EP 3162997 the content of which are incorporated herein by reference. An additional support 5 is provided on the other side of the closure member 3 and may be provided with a lock and keeper assembly, e.g. using a lock disclosed in EP 1118559 or EP 2915939 the content of which are incorporated herein by reference and a keeper disclosed in EP 1600584 or EP 1680567 the content of which is incorporated herein are reference.

[0058] The gate closer 3 is shown in more detail in figure 2 and comprises an elongated housing 9 extending in a longitudinal direction between a first end 9a and a second end 9b. The elongated housing 9 is preferably manufactured from extruded aluminium, but other materials could also be used. The elongated housing 9 is fixed to the support 1 by means of fixture means 6. Preferably fixtures sets as described in EP 1907712 or EP 3575617 are used the content of which are incorporated herein by reference. Other ways of mounting the gate closer 3 to the closure system are also possible (e.g. placing the gate closer inside the hollow support) and details are known to the skilled person.

[0059] On top of the housing 9, a driver 7 (e.g. a rotating arm) is provided which extends from the support 1 to the closure member 2. On the free end of the driver 7, there is an upstanding arm 8 which, as shown in figure 1, engages the eyebolt hinge 4 to urge the closure member 2 to its closed position. More specifically, the arm 8 engages a coupling mechanism provided on the eyebolt hinge as disclosed in WO 2019/048359 the content of which is incorporated herein by reference. In the illustrated embodiment, the driver 7 is manufactured from aluminium

[0060] The gate closer 3 includes an electromotor (not shown) disposed in the housing 9. An electric motor is used due to its compactness. The electromotor comprises a motor body with the means required for rotating an output shaft (not shown). This output shaft extends towards to the top 9a of the housing 9. An example of such an interior construction is shown in figure 7 of WO 2019/048359 which is incorporated herein by reference. The output shaft is rotatable in at least one rotational direction upon activation of the electromotor. However, preferably, the output shaft is able to rotate in both directions as this enables a single gate closer to be used for both left-handed and right-handed closure systems. The electromotor is further provided with control means which allow calibrating the resting position of the driver 8 once the gate closer 3 is mounted on the closure system.

[0061] Figure 3 shows an exterior view of the torque limiter 10 positioned between the driver 7 and the output shaft of the electromotor. Figure 4 shows an exploded view of the torque limiter 10. The torque limiter 10 comprises a cylindrical base 11 that is placed inside the elongated housing 9 at the top end 9a and is free to rotate within the housing 9. The cylindrical base 11 is fixed to the output shaft of the electromotor. The cylindrical base 11 comprises a first side 11a facing away from the housing 9 and a second side 11b facing the elongated housing 9 with a circumferential wall extending therebetween. In the illustrated embodiment, the cylindrical base 11 is manufactured from aluminium. The circumferential wall of the cylindrical base 11 has a crenelated area at the first side 11a, the crenelated area having a plurality of crenels 19 (indicated in figure 5G) separated by merlons 17. The cylindrical base 11 further comprises a central shaft 18 having a through-opening 61 therein with an annular recess 65 between the shaft 18 and the circumferential wall.

[0062] Inside the annular recess 65, a stack of disc springs 12a, 12b, 12c, 12d are positioned. These jointly form a biasing member 12. Naturally other means may be used to form a biasing member. The biasing member 12 has a biasing force of at least 2000 N, particularly at least 3000 N, in a rest position of the biasing member 12. Preferably, when the annular friction disks are disengaged, a biasing force of the biasing member 12 is at least 4000 N, particularly at least 5000 N.

[0063] On top of the biasing member 12 there is provided a washer 13 having a first side 13a facing away from the housing 9 and a second side 13b facing the housing 9. The washer 13 (as shown in figure 5F) comprises an outer crenelated region with merlons 21 and crenels 22 which interlock with the crenelated area of the circumferential wall to rotationally lock the washer 13 to the base 11 whilst allowing a sliding motion in the longitudinal direction. Inside each crenel 22, there is a further merlon 23 which rests (when the biasing member 12 is depressed) on an inner sleeve 20 of the circumferential wall. The washer 11 also has a non-circular central opening 24 which engages the non-cylindrical part of the central shaft 18 to provide a singular position of the washer 13 with respect to the base 11. In the illustrated embodiment, the washer 13 is manufactured from stainless steel.

[0064] The torque limiter 10 further comprises a first annular friction disk 14 having a first side 14a facing away from the housing 9 (shown in figure 5D) and a second side 14b facing the housing 9 (shown in figure 5E). The second side 14b comprises a plurality of circular upstanding ridges 28 that fit into corresponding recesses 25 of the washer 13 to rotationally lock the friction disk 14 to the washer 13. A differently-shaped ridge 27 and recess 26 are used to provide a singular position of the washer 11 with respect to the disk 14. Reinforcing ribs 29 are also provided to further strengthen the ridges 28. The first side 14a of the disk 14 comprises a three-ring structure concentric having an inner ring 32, a central ring 31 and an outer ring 30 which are described further.

[0065] The torque limiter 10 further comprises a second annular friction disk 15 having a first side 15a facing away from the housing 9 (shown in figure 5B) and a second side 15b facing the housing 9 (shown in figure 5C). The first side 15a comprises a plurality of circular upstanding ridges 35 that fit into corresponding recesses 37 of the driver 7 to rotationally lock the friction disk 15 to the washer 7. A differently-shaped ridge 34 and recess 36 are used to provide a singular position of the driver 7 with respect to the disk 15. Reinforcing ribs 35 are also provided to further strengthen the ridges 33. The second side 15b of the disk 15 comprises a three-ring concentric structure having an inner ring 32, a central ring 31 and an outer ring 30 which are described further.

[0066] In the illustrated embodiment, the friction disks 14, 15 are each manufactured from a plastic material having a static coefficient of friction between 0,05 and 0,5, the static coefficient of friction being particularly at least 0,1 and more particularly at least 0,2, the static coefficient of friction being particularly at most 0,4, more particularly at most 0,3 and even more particularly at most 0,2.

[0067] Figure 7 illustrates how the driver 7 is attached to the cylindrical base 11. The figure also shows the biasing member 11 and the washer 13 inside the annular recess 65 of the base 11 with the first friction disk 14 placed on the washer 13 and protruding partially with respect to the base 11. The second friction disk 15 is engaged with the first friction disk 14 and is locked to the driver 7. For assembly purposes, the base 11 is provided with a through-opening 60 and the driver 7 is provided with a threaded hole 61. A fixation bolt 16 with a bolt shaft 16a with a threaded area 39 is position through the through-opening 60 into the threaded hole 61. The fixation bolt 16 includes a flange 16b that, together with the fixation bolt head, and corresponding abutment surfaces on the cylindrical base 11 and the driver 7 define an end position of the fixation bolt 16. The end position is so that there is a minimal spacing between adjacent transverse surfaces of the driver 7 and the cylindrical base 11. Similarly, the shaft section in which the threaded hole 61 is provided has a slightly smaller outer diameter than the through-opening 60 of the cylindrical base 11 causing a minimal spacing between adjacent axial surfaces of the driver 7 and the cylindrical base 11. The fixation bolt 16 creates a certain pre-tension in the biasing member 12 as the friction disk 14 is pushed towards the cylindrical base 11. This pre-tension corresponds to the biasing force of at least 2000 N, particularly at least 3000 N, in the rest position of the biasing member 12.

[0068] Figure 6 illustrates the friction disks 14, 15, particularly the surfaces facing one another, in more detail. Both surfaces 14a, 15b are identical to one another and fit together in one angular position. The surfaces 14a, 15b comprises a plurality of inclined faces 46 which engage with one another to transfer a rotational motion of disk 14 to disk 15. The inclination angle of the inclined faces 46 decreases when moving radially outwards on the annular friction disks 14, 15 with an average inclination angle (determined with respect to the longitudinal direction) being preferably between 20 and 60 degrees, with particular lower limits of 30 degrees and 35 degrees, and with particular upper limits of 55 degrees and 50 degrees.

[0069] The inclined faces 46 are obtained by having a sequential heightened areas 41, 42, 45 and depressed areas 40, 43, 44. As described above, these are divided in concentring rings 30, 31, 32 where heightened and depressed areas 41, 40 form the outer ring 30; heightened and depressed areas 42, 43 form the central ring 31; and heightened and depressed areas 45, 44 form the inner ring 32.

[0070] The inner and outer ring 32, 30 have a different number of heightened areas J and K (namely 6 and 5 respectively) which are relative prime numbers thus ensuring that the friction disks 14, 15 fit together in only a single angular position. The central ring 31 is a continuous zig-zag pattern so as to create maximise the number of inclined faces 46.

[0071] Although aspects of the present invention 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 present invention as defined by the appended claims.

Claims

1. A gate closer (3) for closing a closure system having a support (1) and a closure member (2) that are hingedly connected to each other, the gate closer comprising:

- an elongated housing (9) configured to be mounted to the support, the elongated housing extending in a longitudinal direction between a first end (9a) and a second end (9b);

- an electromotor mounted in the housing, the electromotor having an output shaft near the first end of the elongated housing and which is rotatable around said longitudinal direction in a first rotational direction upon activation of the electromotor; and

- a driver (7) operatively connected to the output shaft, the driver being configured to urge the closure member to its closed position upon rotation of the output shaft in said first rotational direction,

characterized in that the gate closer further comprises a torque limiter (10) disposed between the output shaft and the driver, the torque limiter comprising:

- a cylindrical base (11) positioned at its first end of the elongated housing and being fixed to the output shaft, the cylindrical base having:

- a first side (11b) facing towards the elongated housing;

- a second side (11a) opposite the first side in said longitudinal direction;

- a circumferential wall extending between the first side and the second side; and

- an annular recess (65) with an open side facing away from the elongated housing;

- a first annular friction disk (14) disposed in the annular recess of the cylindrical base and rotationally locked with respect to the cylindrical base, the first annular friction disk comprising a plurality of first inclined surfaces (46) on the side (14a) of the first annular friction disk facing away from the cylindrical base;

- a second annular friction disk (15) disposed adjacent the first annular friction disk and rotationally locked to the driver, the second annular friction disk comprising a plurality of second inclined surfaces (46) on the side (15b) of the second annular friction disk facing the first annular friction disk, said plurality of first and second inclined surfaces being configured to transfer a rotational motion of the first annular friction disk to the second annular friction disk; and

- a biasing member (12) disposed in the annular recess of the base, the biasing member urging the first annular friction disk towards the second annular friction disk thereby engaging said plurality of first and second inclined surfaces with one another.

2. The gate closer according to claim 1, characterized in that the annular friction disks interlock with one another only in a single angular position of the first annular friction disk with respect to the second annular friction disk.

3. The gate closer according to claim 1 or 2, characterized in that the first annular friction disk is slidable with respect to the cylindrical base along said longitudinal direction between an engaging position in which said plurality of first and second inclined surfaces are engaged with one another and a releasing position in which said plurality of first and second inclined surfaces are not engaged with one another.

4. The gate closer according to any one of the preceding claims, characterized in that the gate closer further comprises a washer (13), in particular a washer manufactured from a metal, such as stainless steel, disposed in the annular recess of the cylindrical base and interposed between the first annular friction disk and the biasing member, the washer being rotationally locked to the cylindrical base, the first annular friction disk preferably being rotationally locked to the washer, the washer preferably having a thickness of at least 1,5 mm and more preferably of at least 2 mm.

5. The gate closer according to claim 4, characterized in that the circumferential wall comprises a crenelated region (17, 19) at the second side and that the washer comprises a crenelated outer circumference (21, 22) which interlocks with the crenelated region of the circumferential wall.

6. The gate closer according to claim 4 or 5, characterized in that:

- the washer comprises a plurality of first interlocking means (25, 26) provided on the side (13a) of the washer facing away from the elongated housing and that the first annular friction disk comprises a plurality of second interlocking means (27, 28) provided on the side (14b) of the first annular friction disk facing the washer, said plurality of first and second interlocking means rotationally locking the first annular friction disk to the washer; and/or

- the second annular friction disk comprises a plurality of third interlocking means (33, 34) provided on the side (15a) of the second annular friction disk facing away from the elongated housing and the driver comprises a plurality of fourth interlocking means (36, 37), said plurality of third and fourth interlocking means rotationally locking the second annular friction disk to the driver.

7. The gate closer according to any one of the preceding claims, characterized in that the first annular friction disk comprises a plurality of depressed areas (40, 43, 44) and a plurality of heightened areas (41, 42, 45) with respect to a hypothetical flat disk, the plurality of first inclined surfaces being formed between adjacent ones of the depressed and heightened areas, and
in that the second annular friction disk comprises a plurality of depressed areas (40, 43, 44) and a plurality of heightened areas (41, 42, 45) with respect to a hypothetical flat disk, the plurality of second inclined surfaces being formed between adjacent ones of the depressed and heightened areas.

8. The gate closer according to claim 7, characterized in that the depressed and heightened areas on each annular friction disk form at least an inner ring (32) and an outer ring (30) which are concentric with one another, wherein, preferably, the inner ring has J heightened areas, J being a natural number larger than one, and the outer ring has K heightened areas, K being a natural number larger than one, J and K being relative prime numbers.

9. The gate closer according to claim 8, characterized in that, when the annular friction disks are not in said single angular position:

- the heightened areas of the inner ring of the first annular friction disk at least partially engage the heightened areas of the inner ring of the second annular friction disk and/or the heightened areas of the outer ring of the first annular friction disk at least partially engage the heightened areas of the outer ring of the second annular friction disk, the engagements being substantially uniformly distributed over the circumference of a respective ring; and/or

- the heightened areas of the inner ring of the first annular friction disk at least partially engage the heightened areas of the inner ring of the second annular friction disk and/or the heightened areas of the outer ring of the first annular friction disk at least partially engage the heightened areas of the outer ring of the second annular friction disk, the total engaged surface area being at least 20%, particularly at least 30%, more particularly at least 35%, of a total surface area of the heightened areas on the inner ring and the outer ring of one of the annular friction disks.

10. The gate closer according to any one of claims 7 to 9, characterized in that the depressed and heightened areas on each annular friction disk form at least one additional ring (31) concentric with the inner ring and the outer ring, said at least one additional ring preferably comprising a substantially continuous regular zigzag pattern, said at least one additional ring preferably comprising at least twenty heightened areas.

11. The gate closer according to any one of the preceding claims, characterized in that the driver comprises a threaded hole (61) facing the elongated housing and the cylindrical base comprises a through-opening (60) aligned with said threaded hole, the driver being fixed to the cylindrical base by a fixation bolt (16) which is placed through said through-opening into said threaded hole,
wherein, preferably, the cylindrical base and the driver substantially do not contact one another, the cylindrical base particularly comprising a first abutment surface and the fixation bolt particularly comprising a second abutment surface which abut against one another preventing a further tightening of said fixation bolt.

12. The gate closer according to any one of the preceding claims, characterized in that:

- the inclination of said plurality of first and second inclined surfaces decreases when moving radially outwards on the annular friction disks, an average inclination angle being preferably between 20 and 60 degrees, with particular lower limits of 30 degrees and 35 degrees, and with particular upper limits of 55 degrees and 50 degrees; and/or

- a biasing force of the biasing member is at least 2000 N, particularly at least 3000 N, in a rest position of the biasing member.

13. The gate closer according to any one of the preceding claims, characterized in that:

- the annular friction disks are manufactured, in particular injection molded, from plastic; and/or

- the annular friction disks are manufactured from a material having a static coefficient of friction between 0,05 and 0,5, the static coefficient of friction being particularly at least 0,1 and more particularly at least 0,2, the static coefficient of friction being particularly at most 0,4, more particularly at most 0,3 and even more particularly at most 0,2.

14. The gate closer according to any one of the preceding claims, characterized in that a biasing force of the biasing member, the inclination of said plurality of first and second inclined surfaces, and a static coefficient of friction of the annular friction disks are such that:

- the annular friction disks disengage for a torque exceeding 400 N·m, preferably exceeding 300 N·m and more preferably exceeding 250 N·m; and/or

- the annular friction disks remain engaged for a torque of up to at least 40 N·m, preferably at least 50 N·m, more preferably at least 60 N·m and most preferably at least 65 N·m.

15. A closure system having a support (1) and a closure member (2) that are connected to each other by at least one hinge (4), characterized in that the closure system further comprises a gate closer (3) according to any one of the preceding claims with the elongated housing (9) mounted to the support and the driver (7) engaging the closure member or said at least one hinge.

Drawing