GB2486249A

GB2486249A - Door closer with hydraulic damper

Info

Publication number: GB2486249A
Application number: GB1020869.2A
Authority: GB
Inventors: Alister Peter Reid
Original assignee: Astra Door Controls Ltd
Current assignee: Astra Door Controls Ltd
Priority date: 2010-12-09
Filing date: 2010-12-09
Publication date: 2012-06-13
Also published as: GB201020869D0

Abstract

A door closer comprising an elongate housing, a plunger, a biasing element disposed in the housing, a tension member, an anchor element assembly with a mounting member, and a hydraulic damper for damping the movement of the plunger within the housing. The hydraulic damper comprises a restrictor valve with a threaded adjuster pin with a needle valve member 55 to adjustably restrict the flow of hydraulic fluid between first and second fluid conduits. The needle valve member has a continuously conically tapered part 70 extending rearwardly from a free end 150 towards a threaded portion 152 of the member, relative rotation of the threaded portions 152 154 causes the tapered portion to move towards and away from a coaxial cylindrical surface of a valve bore. A forward region of the tapered part having a smaller diameter 156 D than the diameter of the cylindrical surface d , and a rearward region 158 D of the tapered part having a diameter greater than the diameter of the cylindrical surface. Preferably the taper surface is inclined at an angle of 1 degree and the hydraulic fluid has a viscosity of 60 centistokes at room temperature.

Description

DOOR CLOSER

This invention relates to a door closing device for urging an opened door towards its closed position relative to a doorframe.

More particularly, the invention concerns improvements in a door closer, which is of the kind that usually acts between a door leaf and a doorframe. This type of door closer typically comprises a housing, a plunger movable along the housing, a biasing element disposed in the housing and biasing the plunger inwardly of the housing, and a tension member having one end connected to the plunger and another end, which extends to an anchor element, The housing is normally installed in a bore in the door leaf and the anchor element installed in the doorframe. However, the positions of the housing and the anchor element may be reversed. The biasing element comprises a spring, which operates to bias the plunger, and consequently the tension member, inwardly of the housing, for closing the door. The tension member comprises an articulated element so that the tension member can be bent around the opening angle of the door relative to the door frame.

It is known to provide such concealed door closers with a hydraulic damping assembly, as disclosed for example in the Applicant's earlier WO-A-2005/1 24079, WO-A-2008/1021 15 and WO-A-2009/034310. The hydraulic damping assembly comprises a piston and cylinder assembly that can damp the movement of the plunger. The hydraulic damping assembly comprises circuit for the hydraulic fluid that incorporates an adjustable needle valve assembly. The needle valve can be adjusted to vary the damping force of the hydraulic damping assembly.

There is a general need for such concealed door closers to have a structure to enable them to be incorporated into a variety of different door constructions having a variety of different uses. For example, the British Standard BS.EN 1154, and its equivalent European Standard EN 1154, sets a variety of technical criteria required to be met by door closers, concealed or not. One criterion is that the door closer must have a minimum closing time at particular specified temperatures, which is to ensure that the door closer can properly and promptly act to close the door in the event of a fire.

The BS.EN1 154 standard specifies the following: A. A standard closing time of 5 seconds at +20 °C; B. A minimum closing time of 3 seconds at +40 °C; and C. A maximum closing time of 25 seconds at -15 °C.

We have found that for concealed door closers incorporating a hydraulic damping assembly this demanding performance criterion is difficult to meet because the minimum door closing time at -15 °C can be difficult to achieve.

While some exposed door closers that are fitted between the top of the door leaf and the door frame can meet these criteria of BS.EN 1154, there is a need in the art for a concealed door closer that can readily meet these criteria in a cost-effective manner.

The Applicant's earlier WO-A-2009/0343 10 disclosed a concealed door closer which could meet the criteria of BS.EN 1154 when using particular hydraulic fluids and capable of providing a particular closing force. Normally, concealed door closer arc sold as a range of products similar in construction but having a range of closing forces, higher closing forces being required for closing heavier doors. However, there is a need in the industry for concealed door closers which have a common construction but which can be used in a variety of different environments, in particular at varying temperature, and applications. The choice of hydraulic fluid is based upon the environmental conditions and applications to which the door closer is expected to be exposed during its working life.

However, the concealed door closer of WO-A-200910343 10 had different performance characteristics dependent upon the choice of hydraulic fluid and based on the closing force. This meant that variation of the valve structure, in particular variation of the taper angle of the needle valve, was required to accommodate different hydraulic fluids selected for particular working environments and closing forces.

Also, the valve structure is configured to be adjustable afler installation. There is a need to provide a concealed door closer with an adjustable valve structure that can pennit a user readily to achieve fine control of the damping function and still permit the criteria of BS.EN 1154 to be achieved over a wide temperature range with a variety of hydraulic fluids.

There is therefore a need for a concealed door closer which can meet the criteria of BS.EN 1154 when using a variety of different hydraulic fluids without requiring a structural modification of the valve structure dependent upon a selected hydraulic fluid or on the closing force or application of the door closer.

The present invention at least partially aims to overcome the problems of the known door closers described hereinabove.

Accordingly, the present invention provides a door closer for mounting between a door leaf and a door frame, the door closer comprising: an elongate housing for mounting in one of the door leaf or door frame, a plunger disposed in and movable along the housing, a biasing element disposed in the housing and biasing the plunger inwardly of the housing, a tension member having a first end connected to the plunger and a second end connected to an anchor element assembly, the anchor element assembly comprising a mounting member, for mounting in the other of the door leaf or door frame, and a hydraulic damper for damping the movement of the plunger within the housing, wherein the hydraulic damper comprises a restrictor valve having a threaded adjuster pin for adjusting the operation of the hydraulic damper, the threaded adjuster pin being threadably mounted in the plunger in an elongate cavity therein, the threaded adjuster pin having a needle valve member which is adapted adjustably to restrict the flow of hydraulic fluid in the damper between first and second fluid conduits respectively located at a free end and at a lateral side of the plunger, wherein the needle valve member has a continuously conically tapered part extending rearwardly from a free end of the needle valve member towards a first threaded portion of the needle valve member, the first threaded portion being threadably coupled to a second threaded portion in the plunger, the tapered surface of the needle valve member being selectively movable, by relative rotation of the first and second threaded portions, towards and away from a cylindrical surface of a valve bore which extends between the first and second fluid conduits, the continuously conically tapered part and the cylindrical surface being coaxial, with a forward region of the continuously conically tapered part having a smaller diameter than the diameter of, and being fitted within, the cylindrical surface, and a rearward region of the of the continuously conically tapered part having a diameter greater than the diameter of the cylindrical surface.

Optionally, the continuously conically tapered part extends from the free end of the needle valve member to the first threaded portion of the needle valve member.

Optionally, the tapered surface is inclined at an angle of about 1 degree with respect to a longitudinal axis of the needle valve member, Optionally, the threaded adjuster pin is captive in the plunger.

In particular, the preferred embodiments of the present invention can provide a concealed door closer that can readily be structured to provide the minimum door closing time required by BS.EN 1154 in a cost-effective manner, since a single valve structure can be manufactured for use with a variety of different viscosity hydraulic fluids and with a variety of different spring closing forces.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a partly cut-away perspective side view of a door closer according to an embodiment of the present invention in a closed configuration; Figure 2 is a partly cut-away perspective side view of the door closer of Figure 1 in an open configuration; Figure 3 is a schematic perspective view of the assembly of the link member to the plunger head by the rigid tension member of the door closer of Figure 1; Figure 4 is a sectional view through the plunger head, rigid tension member and hydraulic adjuster pin of the door closer of Figure 1; and Figure 5 shows an enlarged sectional view of part of the hydraulic adjuster pin of the door closer of Figure 1.

Figures 1 to 5 show a door closer according to the present invention that can be used for urging an opened door towards its closed position relative to a door frame; An elongate housing 2 in the form of a cylindrical tube comprises a biasing element 4 (shown in phantom) in the form of a helical compression spring. In Figures 1 and 2, for clarity of illustration only the opposed ends of the helical compression spring 4 are shown and the central portion is not shown. A plunger 6 is disposed in and movable along the housing 2. The plunger 6 is biased inwardly of the housing 2 by the biasing element 4.

The helical compression spring 4 annularly surrounds the plunger 6. The housing 2 has a mounting plate 8 affixed thereto, the mounting plate 8 having holes 10 extending therethrough for receiving fixing screws. In use, the housing 2 is received in an elongate horizontal cavity in a door leaf (not shown), and the mounting plate 8 is rebated into the edge of the door leaf and affixed thereto, for example by screws.

A rigid tension member 14 has a first end 16 pivotally connected at a first pivot 18 to a 1: plunger head 17 of the plunger 6 and a second end 20 pivotally connected at a second pivot 22 to an anchor element assembly 24. The first pivot 18 has a knurled outer cylindrical surface 19 securely fitting into a cylindrical hole 21 in the plunger head 17, the knurling preventing inadvertent removal of the first pivot 18. The anchor element assembly 24 comprises a mounting member 26, in the form of a plate, for mounting in a door frame (not shown) and an elongate link member 30 extending from the mounting member 26. The mounting member 26 is typically rebated into the edge of the door frame and affixed thereto, for example by screws. The second pivot 22 is located at a free end 32 of the link member 30 remote from the plate member 26. The first and second pivots 18, 22 have parallel axes 19, 23.

Conceivably, the mounting positions of the housing 2 and the anchor element assembly 24 may be reversed, with the housing 2 received in the door frame and the anchor element assembly 24 mounted to the door leaf A hole 34 in the mounting plate 8 permits movement therethrough of the rigid tension member 14 and the link member 30.

The rigid tension member 14 comprises a linearly straight body 36 that has a central portion 37 between the first and second ends 16, 20. At least a part of the central portion 37 has a reduced thickness relative to the first and second ends 16, 20 in a direction orthogonal to the axes 19, 23 of the first and second pivots 18, 22. In particular, the central portion 37 includes an elongate recess 38 extending longitudinally along a side surface 40 thereof that is a radially inner surface of the rigid tension member 14 during a door opening/closing operation of the door closer 2. The recess 38 has a depth that is greater than 50% of the thickness of the first and second ends 16, 20. The recess 38 has a length that is greater than 50% of the distance between the first and second pivots 18, 22, The recess 38 has a linearly straight bottom surface 39 located between opposed first and second areuate ends 41, 43. The recess 38 is located longitudinally nearer to the first pivot 18 than to the second pivot 22.

In accordance with the preferred embodiment of the invention, the link member 30 extends from the mounting member 26 at an angle of up to 20 degrees, preferably from 5 to 15 degrees, typically about 10 degrees. The second pivot 22 is a first distance x (in one embodiment about 21 mm) from the mounting member 26 and the first and second pivots 18, 22 are spaced apart by a second distance y (in that one embodiment about 56 mm).

Typically, the ratio of the second distance y to the first distance x is from 5:1 to 1:1, more typically from 3:1 to 2:1, yet more typically about 2.5:1.

The door closer of the invention also incorporates an adjustable damper 50, shown in detail in Figures 4 and 4, to provide a decelerated or damped closing action. Adjustable hydraulic cylinder/piston dampers are known in the art, as disclosed for example in WO-A-2005/124079, WO-A-2008/l021l5 and WO-A-2009/034310. The hole 34 permits insertion therethrough of a screwdriver or other tool to adjust the damper 50.

In the illustrated embodiment a hydraulic cylinder/piston damper 50 for damping the movement of the plunger 6 within the housing 2, having the general structure as disclosed for example in WO-A-2005/124079, WO-A-2008/102115 and WO-A-2009/0343l0 is provided. The hydraulic cylinder/piston damper 50 has a threaded adjuster pin 52 for adjusting the operation of the hydraulic damper 50. The threaded adjuster pin 52 is mounted in the plunger head 17 of the plunger 6 adjacent the first pivot 18 and has an elongate head 54 which extends away from the plunger 6 and lies adjacent to the rigid tension member 14. The extending part of the threaded adjuster pin 52 may extend more than 40%, even more than 50%, along the length of the rigid tension member 14.

At the other end of the threaded adjuster pin 52 a needle valve member 55 of a restrictor valve 57 is provided which is employed to restrict, and adjust, the flow of hydraulic fluid in the damper 50. The restrictor valve 57 can be adjusted to adjust the operation of the hydraulic damper 50. The threaded adjuster pin 52 is threadably mounted in the plunger 6 in an elongate cavity 60 therein, which cavity 60 communicates with first and second conduits 62, 64 respectively located at a free end and at a lateral side of the plunger 6. The needle valve member 55 is adapted adjustably to restrict the flow of hydraulic fluid in the damper 50 between the first and second fluid conduits 62, 64. The first conduit 62 is coaxial with the threaded adjuster pin 52 and located distally, in a longitudinal direction, of the needle valve member 55, whereas the second conduit 64 is orthogonal to the axis of the threaded adjuster pin 52, and located adjacent, in a radial or lateral direction, to the needle valve member 55.

The needle valve member 55 has a continuously conically tapered part 66 extending rcarwardly from a free end 150 of the needle valve member 55 towards, and as far as, a first threaded portion 152 of the needle valve member 55. The first threaded portion 152 is threadably coupled to a second threaded portion 154 in the plunger 6. The frustoconical tapered surface 70 of the needle valve member 55 is selectively movable, by relative rotation of the first and second threaded portions 152, 154 by rotation of the threaded adjuster pin 52, towards and away from a fixed cylindrical surface 68, comprising a valve seat, of a valve bore 72 of the restrictor valve 57 in the plunger 6.

The valve bore 72 extends between the first and second fluid conduits 62, 64, the continuously conically tapered part 66 and the cylindrical surface 68 being coaxial, with a forward region 156 of the continuously conically tapered part 66 having a smaller diameter than the diameter of, and being fitted within, the cylindrical surface 68. In contrast, a rearward region 158 of the continuously conically tapered part 66 has a diameter greater than the diameter of the cylindrical surface 68.

The valve bore 72, including the cylindrical surface 68, has a diameter, d, which is typically 2mm. The forward region 156 has a diameter D' less than d, and the rearward region 158 has a diameter D" greater than d. This provides that the frusto conical surface always interfaces with the cylindrical surface 68 to provide the annular gap 74.

The restrictor valve 57, when open, forms an annular gap 74 between the frustoconical surface 70 and the fixed cylindrical annular surface 68. The annular gap 74 has a radial width determined by the longitudinal position of the threaded adjuster pin 52 in the plunger 6. The dimension of the radial width of the annular gap 74 determines the degree of restriction to hydraulic fluid flow through the restrictor valve 57, in particular in a fluid flow direction from the second conduit 64 to the first conduit 62 through the intermediary valve bore 72. This correspondingly determines the degree of hydraulic damping imposed on the closing movement of the door closer by the damper 50.

The valve bore 72, including the cylindrical surface 68, has a diameter, d, which is typically 2mm. The forward region 156 has a diameter D' less than d, and the rearward region 158 has a diameter D" greater than d. This provides that the frustoconical surface always interfaces with the cylindrical surface 68 to provide the annular gap 74.

In contrast, in the door closer disclosed in the Applicant's earlier WO-A-2009/0343 10 the needle valve member had a diameter along its entire length which was less than that of the valve bore, and also had a cylindrical portion at the rearward end adjacent to the threaded portion.

The present inventor has found that by ensuring that a frustoconical surface 70 of the needle valve member 55 was spaced from the fixed cylindrical annular surface 68 of the valve bore 72, the same valve structure, with the same taper angle, could be used with a variety of different hydraulic fluids of varying viscosity suitable for varying environments, and provide operating performance meeting the criteria of BS.EN 1154, In particular, a good damping performance is achieved over a wide temperature range using low viscosity fluids. Also, the same valve can be used for different closing forces, the closing force varying with different spring constants of the spring 4, and still provide an operating performance meeting the criteria of BS.EN 1154.

The valve structure is configured to be adjustable afler installation, and the interface between the frustoconical surface 70 and the fixed cylindrical annular surface 68 of the valve bore 72 at all possible positions of the needle valve member 55 permits a user readily to achieve fine control of the damping function and the criteria of BS.EN 1154 to be achieved over a wide temperature range with a variety of hydraulic fluids. Most particularly, such fine control can be achieved even with a hydraulic fluid of low viscosity, such as 60 centistokes at room temperature, the advantage of such a low viscosity fluid being the minirnisation of the risk of jamming of the door closer, particularly at lower operating temperatures.

The concealed door closer can meet the criteria of BS.EN 1154 when using a variety of different hydraulic fluids without requiring a structural modification of the valve structure dependent upon a selected hydraulic fluid or on the closing force or application of the door closer.

Typically, the frustoconical tapered surface 70 is inclined at an angle, A in Figure 5, of about 1 degree with respect to a longitudinal axis B of the needle valve member 55.

Figure 5 is not to scale for the purpose of clarity of illustration.

The hydraulic fluid 76 of the hydraulic damper 50 may be selected from a hydraulic fluid, a glycol-based fluid or a silicone-base fluid, and may have a wide viscosity range, but most particularly a low viscosity. A typical viscosity is 60 centistokes at room temperature.

The threaded adjuster pin 52 is captive in the plunger 6 by the first pivot 18, and is prevented from moving beyond respective defined positions in both longitudinal directions. An end 56 of the first pivot 18 is disposed outwardly of an inner stop surface 59 of the threaded adjuster pin 52. The threaded adjuster pin 52 is surrounded by an 0-ring 51 between the needle valve member 54 and the inner stop surface 59 which hydraulically seals hydraulic fluid within the damper 50.

By providing a captive threaded adjuster pin 52, caused by engagement between end 56 and the inner stop surface 59, inadvertent complete removal of the pin by the user is prevented. This would cause loss of hydraulic fluid from the damper 50, and failure of the device, The use of the first pivot 18 to capture the threaded adjuster pin 52 in the plunger 6 reduces component costs,, because the first pivot 18 performs two functions, and simplifies the assembly operation during manufacture.

Also, by extending the threaded adjuster pin 52 by means of the provision of the elongate head 54 which extends away from the plunger 6 and lies adjacent to the rigid tension member 14, the user can employ a screwdriver to rotate the threaded adjuster pin 52 to adjust the damper 50 operation without having to open the door to its fullest extent against the closing bias of the door closer. Even when the door is only partly open, when there is a reduced closing bias from the door closer, the end of the elongate head 54 is exposed at the hole 34 permitting adjustment by the user. This is a significant practical advantage to the user, particularly when the user is frail.

Most preferably, the end of the elongate head 54 is exposed when the door is opened to approximately 90 degrees. This reduces or prevents unauthorised tampering with the threaded adjuster pin 52. A requirement of the European Standard EN 1154 on door closers states that "Control regulators shall either be concealed or operable only by way of a tool". The preferred embodiments clearly meet this stipulation of the standard.

The closed door position is shown in Figure 1. The mounting plate 8 and the plate member 26 abut, The rigid tension member 14 is wholly received in the housing 2, and the link member 30 is also received in the housing 2. The helical compression spring 4 has urged the plunger 6 to its most inward position with respect to the housing 2.

When the door leaf is opened relative to the door frame about the axis of one or more door hinges (not shown), the plunger 6, being attached to the door frame, is pulled in a direction outwardly of the housing 2. Accordingly, the helical compression spring 4 is progressively compressed, as a result of a compression force acting thereon by the plunger 6, and exerts an inward biasing force acting against the opening pulling force on the door leaf The open position is shown in Figure 2. The mounting plate 8 is spaced from the plate member 26. The link member 30 is pulled out of the housing 2 and the rigid tension member 14 is partly received in the housing 2. The rigid tension member 14 is rotated relative to the plunger 6 about the first pivot 18. The link member 30 is rotated relative to the rigid tension member 14 about the second pivot 22.

In the fully open position, in which the door leaf has been opened by an angle of up to 1200, the rigid tension member 14 is pulled completely out of the housing 2 and the first pivot 18 and the associated end of the plunger 6 are disposed at the hole 34. The rigid tension member 14 has been rotated relative to the plunger 6 about the first pivot 18 so as to lie, in the fully open position, at an angle of up to about 120° relative to the longitudinal axis of the door closer 2. The link member 30 has been rotated relative to the rigid tension member 14 about the second pivot 22.

To achieve the fully open position, the rigid tension member 14 has been rotated towards a side edge 42 of the hole 34. By providing the concave recess 38 on the radially inner surface 40 of the rigid tension member 14, during the door opening/closing operation of the door closer 2 the side edge 42 is received in the concave recess 38 so as to avoid any contact between the rigid tension member 14 and the housing 2 or the mounting plate 8 that would inhibit the door opening/closing operation. Even when the rigid tension member 14 is at an angle of up to 120° relative to the longitudinal axis of the door closer 2, so that the rigid tension member 14 acutely inclined to the mounting plate 8, the side edge 42 is received in the concave recess 38 without contact therebetween. This concave recess 38 therefore enables a much larger opening angle to be achieved, while using a rigid tension member 14, in the form of a linearly straight body, which can transmit a large closing force to the door leaf even when the door leaf is fully opened to an angle of up to 120°.

By providing that the link member 30 extends towards the rigid tension member 14 at an angle inclined to the orthogonal to the plane of the door frame, this provides that the link member 30 can still readily pass through the hole 34 and be accommodated within the housing 2 when the door leaf is closed, but the selected angle causes the link member 30 to be inclined towards the final open orientation of the rigid tension member 14, reducing the angle therebctween in the final open configuration. This in turn reduces the total angular movement of the rigid tension member 14, and permits a higher opening angle to be achieved for a given shape and geometry of the rigid tension member 14 and of the hole 34. This also permits a high closing force to be achieved at the opening angle of up to After the door leaf is released, the biasing force of the helical compression spring 4 acts to bias the rigid tension member 14 inwardly of the housing 2, for closing the door. The damper may provide a reduced damping force at the end of the closing operation so as to provide an enhanced closing velocity for overcoming any latch resistance so that the door is securely latched when closed.

Claims

CLAIMS: 1. A door closer for mounting between a door leaf and a door frame, the door closer comprising: an elongate housing for mounting in one of the door leaf or door frame, a plunger disposed in and movable along the housing, a biasing element disposed in the housing and biasing the plunger inwardly of the housing, a tension member having a first end connected to the plunger and a second end connected to an anchor element assembly, the anchor element assembly comprising a mounting member, for mounting in the other of the door leaf or door frame, and a hydraulic damper for damping the movement of the plunger within the housing, wherein the hydraulic damper comprises a restrictor valve having a threaded adjuster pin for adjusting the operation of the hydraulic damper, the threaded adjuster pin being threadably mounted in the plunger in an elongate cavity therein, the threaded adjuster pin having a needle valve member which is adapted adjustably to restrict the flow of hydraulic fluid in the damper between first and second fluid conduits respectively located at a free end and at a lateral side of the plunger, wherein the needle valve member has a continuously conically tapered part extending rearwardly from a free end of the needle valve member towards a first threaded portion of the needle valve member, the first threaded portion being threadably coupled to a second threaded portion in the plunger, the tapered surface of the needle valve member being selectively movable, by relative rotation of the first and second threaded portions, towards and away from a cylindrical surface of a valve bore which extends between the first and second fluid conduits, the continuously conically tapered part and the cylindrical surface being coaxial, with a forward region of the continuously conically tapered part having a smaller diameter than the diameter of, and being fitted within, the cylindrical surface, and a rearward region of the of the continuously conically tapered part having a diameter greater than the diameter of the cylindrical surface.
2. A door closer according to claim 1, wherein the continuously conically tapered part extends from the free end of the needle valve member to the first threaded portion of the needle valve member.
3. A door closer according to claim 1 or claim 2, wherein the tapered surface is inclined at an angle of about 1 degree with respect to a longitudinal axis of the needle valve member.
4. A door closer according to any one of claims 1 to 3, wherein the threaded adjuster pin is captive in the plunger.
5. A door closer according to any foregoing claim, wherein the hydraulic damper is filled with a hydraulic fluid having a viscosity of about 60 centistokes at room temperature.