Information
-
Patent Grant
-
6625847
-
Patent Number
6,625,847
-
Date Filed
Monday, January 14, 200222 years ago
-
Date Issued
Tuesday, September 30, 200321 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 016 54
- 016 56
- 016 50
- 016 51
- 016 59
- 016 68
- 016 72
- 016 76
- 016 71
- 016 85
- 016 86 C
- 016 61
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International Classifications
-
Abstract
A door closer comprises an actuator assembly (20) adapted for fitting within the thickness of a door and an anchor member (10) adapted for fitting in a door frame in opposed relation to said edge face of the door. An operating member (30) is driven by spring means (45) and coupled to said anchor member (10) to draw the door towards the door frame. An adjustable fluid-filled damper (50) is coupled to said operating member (30) and arranged to provide variable regulation the rate of movement of the operating member under the force of said spring means (45). Resilient thrust means (85) are arranged to exert an increased driving force of said operating member (30) and adjustable control means (100) are provided whereby said thrust means (85) is operative to augment the driving force to said operating member (30) over a defined but variable part of said range of movement corresponding to movement of the door over the final part of its movement into its closed position.
Description
DESCRIPTION OF INVENTION
This invention concerns door closers of the kind comprising an actuator assembly intended for concealed fitting within the thickness of a door, and an anchor member for fixing to a door frame, and in which an operating member is coupled to said anchor member and is movable within the actuator assembly under the action of driving means, usually comprising one or more mechanical springs, and under the control of a uni-directionally operative fluid-filled damper which serves to regulate the rate of movement of the door in the direction of closure without significantly restricting the rate of movement of the door in the direction of opening.
It is desirable for the action of any damper in such a door closer to be adjustable so as to enable the rate of closure to be set to fall within a chosen range despite variations in the weight and other parameters of different doors with which the closer may be used, and for the closer to provide an augmented closing force as the door reaches its closed position in order to overcome resistance from any latch fitted to the door.
GB 2 044 840 A discloses such a door closer, which comprises an actuating assembly which is disposed in a housing that is located within the thickness of the door, having an operating member which is movable linearly by means of one or more coil springs, and coupled by a flexible linkage to the anchor member which is attached to the door frame.
EP 0 016 445 A discloses a door closer of this type in which adjustment of the final part of the closure movement of the door is achieved by means of an adjustment member associated with the anchor member which is attached to the door frame, the adjustment member being disposed behind a mounting plate of the anchor member at a variable spacing so as effectively to adjust the length of the coupling between the anchor member and the operating member in the actuator assembly. This arrangement does not make any provision for adjustment of the overall rate of closure, but only in the final closure position of the door relative to a final part of the travel of the piston in the door-closing direction, in which final part of the travel the action of the damper is rendered ineffective so as to provide for a locally increased rate of closure movement to overcome any resistance which may be offered by a door latch for example.
Although the rate of movement of the door as it approaches its position of closure is increased, there is no provision for adjusting the driving force applied to the door over the final part of closure movement, as relieving the effect of the damper does not increase the force applied by the driving springs, but only allows the door to accelerate in response to the driving force and the closing action then relies on the momentum of the moving door to overcome latch resistance. However, the acceleration achieved depends on many variable factors, including the weight of the door, wind loading on the door, and frictional resistance in die hinges and in the latch itself etc., and accordingly such designs do not entirely address the problem of overcoming resistance associated with a door latch.
DE 1 708 349 A discloses a door closer having a main spring which acts over the full range of movement of a rod which is coupled by a link to and anchor member, and a supplementary spring arranged end to end with the main spring and effective to increase the driving force applied to the rod over the final part of the closure stroke, but without provision for varying the point at which the supplementary spring becomes effective.
Accordingly, it is an object of the present invention to make provision for an augmented closure force to come into play as the door approaches its position of closure, as compared with the force applied throughout the remainder of the range of movement, whilst providing for adjustment of the operation to suit a wide range of requirements not achieved previously.
According to a first aspect of the invention we provide a door closer comprising in combination:
an anchor member for mounting on a door frame,
an actuator assembly for mounting within the thickness of a door which is hinged for movement between open and closed positions relative to said door frame,
an operating member coupled by an articulated link to said anchor member and mounted in said actuator assembly for a range of movement between a retracted position in which said anchor member is held immediately adjacent to said actuator assembly and an extended position in which said anchor member is held in spaced relation to said actuator assembly,
resilient driving means arranged to exert a driving force on said operating member in a manner such as to drive said operating member towards said retracted position and thereby draw said anchor member and said actuator assembly together such that, when installed, the door closer acts to draw the door into its closed position relative to the frame,
a damper connected to said operating member so as to control the rate of movement of the operating member in at least a direction towards said retracted position, said damper comprising a cylinder containing hydraulic fluid, a piston rod carrying a piston which divides the cylinder into two chambers, and flow-restricting means to limit the rate of flow of hydraulic fluid flow one of said chambers to the other at least in one direction of fluid flow in response to movement of said operating member towards said retracted position, an adjustable throttle which comprises two elements in combination, the flow restriction imposed on the hydraulic fluid by said throttle being variable by relative positional adjustment of said two throttle elements, and an adjustment member to enable one of said throttle elements to be positionally adjusted relative to the other so as to vary the flow restriction imposed on the hydraulic fluid by said throttle,
resilient thrust means arranged to exert an increased driving force on said operating member, and
control means whereby said thrust means is operative to apply said increased driving force to said operating member over a defined part of said range of movement as said operating member approaches said retracted position, corresponding to movement of the door over the final part of its movement into its closed position, and
an adjustment member operatively connected with said control means to vary the point in the range of movement of said operating member at which said resilient thrust means becomes operative to apply said increased driving force.
The control means preferably includes a detent means arranged to hold the thrust means in a stressed condition over the whole of the range of movement of the operating means apart from said defined part thereof.
In one arrangement, the thrust means may include a compression spring located within a guide member which is coupled to said operating means and slidable therewith along a fixed shaft, and the detent means may be mounted on a carrier member which abuts one end of the compression spring and is slidable on said fixed shaft and located on this said guide member for limited movement longitudinally thereof, the detent means being engagable in an internal recess formed within said guide member to hold the compression spring in a compressed condition, and being displaceable from said internal recess to release said compression spring at a predetermined position along said shaft.
The detent means may be displaceable from said position of engagement with said internal recess in said guide member into a position of engagement with an external recess formed in said shaft to hold said carrier member in a predetermined position on said shaft. Preferably, the detent means comprises a plurality of balls located in one or more transverse bores formed in the carrier member, and each of said balls is of a diameter greater than the radial spacing between said shaft and said guide member so that said balls are either held by said shaft in said internal recess in said guide member or by said guide member in said external recess in said shaft.
In a particularly preferred arrangement, the bores in which the balls are located are formed with a radially inner portion having a diameter such as to accept the ball with a slight clearance and a radially outer portion having a greater diameter, the two portions of the bore meeting at an internal shoulder which is located at a spacing from the shaft which is less than the radius of the ball. With this arrangement when the ball is held in the internal recess of the guide member, it has been found that the ball does not bind on the shaft, thereby allowing the shaft to move freely relative to the carrier.
In a preferred arrangement the cylinder of the damper is moveable relative to the actuator assembly and the piston is static, and the flow restriction means is incorporated into said piston and piston rod, and the adjustment member has an operating element which is accessible from one end of said piston rod.
The adjustment member may comprise a shaft located within an axial bore formed in said piston rod, with an external threaded formation engaging an internal threaded formation in the bore of the piston rod whereby rotation of the shaft varies its axial position within said bore. The shaft may be provided at one end with a needle formation which comprises one of said throttle elements to cooperate with an orifice defined by the other of said elements, and at its other end with a head formation whereby the shaft may be rotated.
The thrust means may comprise one or more spring elements having a higher rate than the resilient driving means. Preferably both the driving means and the thrust means comprise one or more coiled compression springs, but other arrangements are possible. For example the thrust means may comprise one or more stacks of Belville washers, and the driving means could comprise gas-springs.
In a particularly convenient arrangement, said thrust means and said driving means each comprise two elements disposed symmetrically relative to a single damper means, but other arrangements are possible.
These and other features of the invention will now be described by way of example with reference to the accompanying drawings wherein:
FIGS. 1A and 1B
are partially sectioned side views of one embodiment of door closer to which the invention is applied, comprising an anchor assembly and an actuator assembly, and shown with these assemblies respectively in the “door closed” condition and in the “door open” condition;
FIG. 2
is a front end view of the actuator assembly in the direction of arrow II of
FIG. 1B
,
FIG. 3
is a horizontal section on the line III—III of
FIG. 1B
,
FIG. 4
is a composite section substantially on the line IV—IV of
FIGS. 1A and 1B
,
FIG. 5
is a longitudinal section through an adjustable damper assembly incorporated in the closer.
FIG. 6
is a longitudinal section on the line VI—VI of
FIG. 1B
showing the construction of thrust means in a first, compressed condition,
FIG. 7
is a longitudinal section on the line VII—VII of
FIG. 1A
showing the construction of thrust means in a second, uncompressed condition,
FIG. 8
is a transverse section on an enlarged scale on the line VIII—VIII of
FIG. 6
,
FIG. 9
is a section on the line IX—IX of
FIG. 8
,
FIG. 10
is a graph relating the closure force obtained from a closer in accordance with the invention to the angle of opening, and
FIG. 11
is a graph relating the door closure speed to door closing time.
The door closer as illustrated in
FIGS. 1
to
9
comprises an anchor assembly
10
which is adapted for mounting a door frame at a vertical edge thereof facing the hinged edge of a door hingedly carried by the frame, and an actuator assembly
20
which is adapted for mounting within the thickness of the door.
The anchor assembly
10
comprises a mounting plate
11
and an adjustment plate
12
which is spaced from the mounting plate on the side thereof remote from the door by an adjustable distance. An adjusting screw
13
is engaged in a threaded hole
14
formed in the adjustment plate
12
and a slotted head portion
15
of the screw bears against the mounting plate
12
and is accessible through a central hole
16
formed in the mounting plate
11
. It will be understood that by rotation of the screw
13
the spacing of the adjustment plate
12
and mounting plate
11
can be varied for the purpose hereinafter described.
The mounting plate
11
is also formed with a pair of apertures
17
near the ends thereof and the adjustment plate
12
is formed with a pair of apertures
18
aligned with the apertures
17
whereby the adjustment plate
12
is coupled to an operating member
30
of the actuator assembly
20
as hereinafter described.
The actuator assembly
20
is so dimensioned as to be suitable for fitting within the thickness of the door and for this purpose is provided with a mounting member
21
having bosses near the outer ends thereof formed with apertures
22
which align with the apertures
17
of the anchor assembly mounting plate
11
, a central boss formed with a bore
23
, and intermediate bosses formed with a respective bore
24
having a reduced diameter portion intermediate the ends thereof, as shown clearly in FIG.
1
A.
The apertures
22
locate therein fixed sleeves
25
which are provided with an external flange
26
abutting against the end face of the boss around aperture
22
. The central bore
23
is partially threaded to receive a threaded end portion of a rod
27
, and the intermediate bores
24
each locate one end of a respective shaft
28
secured therein by means of screws as shown. The sleeves
25
, rod
27
and shaft
28
extend parallel to one another and the ends of the shafts
28
furthest from the mounting member
21
are supported by a transverse stop plate
29
which is secured to the free end of the rod
27
by means of a screw or the like.
The actuator assembly
20
further includes an operating member
30
, as above-mentioned, which is carried by the mounting member
21
and guided for longitudinal movement by the sleeves
25
, rod
27
and shafts
28
. The operating member
30
includes a pair of parallel shafts
31
which are located in the sleeves
25
, and each has at one end a pivotal connection
32
to a respective rigid link
33
which is disposed within the associated sleeve
25
when the closer is in the “door closed” condition as shown in FIG.
1
A. The links
33
have a pivotal connection
34
with respective headed studs
19
which extend through the apertures
17
in the mounting plate
11
and through apertures
18
of the adjustment plate
12
of the anchor assembly
10
. The links thus form an articulated connection between the shafts
31
and the anchor assembly
10
.
The operating member
30
further includes, at the other end of the shafts
31
, a cross-head
35
by which the shafts
31
are interconnected. The cross-head
35
is formed with outermost bosses with apertures
36
through which the shafts
31
extend and the cross-head is secured to the shafts
31
by means of pins (not shown). As seen most clearly in
FIGS. 5
,
6
and
7
, the cross-head
35
is also formed with a central boss and a central aperture
37
in which the end of the rod
27
is located with a sealing ring, and a pair of intermediate bosses with apertures
38
through which the shafts
28
pass with clearance.
The operating member
30
is movable inwardly towards a retracted or “door closed” position as shown in
FIG. 1A
under the force of driving springs
45
, which, in the illustrated embodiment, compromise coil springs extending between the cross-head
35
and the flanges
26
on the fixed sleeves
25
. In addition, floating sleeves
40
are located on each of the shafts
31
and carry a respective clip
41
which engages between turns of the respective spring
45
. Alternatively, separate springs may be provided on opposite sides of the clip
41
.
As will be evident, the compression springs
45
act on the cross-head
35
to drive the latter inwardly of the actuator assembly
20
to the retracted position and to draw the shafts
31
and the associated links
33
inwardly so as to bring the mounting plate
11
of the anchor assembly
10
up to the mounting member
21
of the actuator assembly, in the manner illustrated in
FIG. 1A
, thereby holding the door in its closed position.
When the door is opened, as shown in
FIGS. 1B and 3
, the shafts
31
and cross-head
35
are drawn outwardly, thereby causing the springs
45
to be compressed, abutment of the floating sleeves
40
against the fixed sleeves
25
limiting the outward travel of the cross-head
35
at an extended or “door open” position. When the door is released, the coil springs
45
act to return the cross-head
35
and the shafts
31
to their starting positions, thereby bringing the door back to its closed position relative to the frame.
The actuator assembly
20
further includes a damper assembly
50
to regulate the rate of closure of the door under the action of the springs
45
.
The damper assembly
50
as shown in
FIG. 5
comprises a fixed piston
51
formed on the rod
27
at an intermediate position, and a cylinder
52
carried by the cross-head
35
and containing hydraulic fluid. The cylinder
52
is located at one end, with an appropriate seal, in a recess
53
formed in a boss at the centre of the cross-head
35
, and is closed at its other end by a plug
54
, which is retained by means of a clip
55
in the mouth of the cylinder. The plug
54
is formed with a bore
56
through which the piston rod
27
passes. Appropriate sealing rings
57
,
58
are arranged to engage sealingly with the exterior surface of the rod
27
and with the interior surface of the cylinder
52
as shown.
In the illustrated embodiment the fixed piston rod
27
is assembled from first and second rod sections
59
,
60
. The first rod section
59
is formed with a radial enlargement having a peripheral groove
61
for a sealing ring
62
which engages with the interior face of the cylinder
52
so that the enlargement serves as the piston
51
. The second rod section
60
includes a widened end portion
63
which has in internal bore
64
to receive an end portion of the first rod section
59
.
The piston
51
divides the cylinder
52
into inner and outer compartments
65
,
66
and fluid passageways as hereinafter described are formed in the piston
51
and the rod
27
to enable hydraulic fluid to pass from one compartment of the cylinder to the other in a controlled manner.
Axial passageways
67
extend directly between opposite faces of the piston
51
. The widened end portion
63
of the second rod section
60
has an end face
68
which is spaced axially from the piston
51
, and a flexible seal
69
is disposed between the end face
68
and the piston
51
. The flexible seal
69
is moveable within the gap between the end face
68
and the piston
51
in response to fluid pressure so to close or open the axial passageways
67
.
The flexible seal
69
lifts from the ends of the axial passageways
67
in response to opening movement of the door, so that fluid may flow freely from the inner compartment
65
to the outer compartment
66
and the door may be opened freely. However, in response to movement of the door towards its closed position the flexible seal
69
covers the ends of the axial passageways
67
in such a manner as to prevent liquid flowing directly from the outer compartment
66
to the inner compartment
65
through the axial passageways
67
.
To enable fluid to flow from the outer compartment
66
to the inner compartment
65
, radial passageways
70
are formed in the first rod section
59
adjacent to the face of the piston which is presented towards the cross-head
35
to communicate with a central bore
71
which terminates, at the end of the first rod section
59
which is presented towards the mounting member
21
, in a throttling orifice
72
. Further radial passageways
73
extend from the outer face of the widened end portion
63
of the outer rod portion
60
to a central chamber
74
formed at the inner end of an axial bore
75
which extends through the second rod section
60
to its outer end where it is received in the central bore
23
of the mounting member
21
.
The axial bore
75
includes a widened end portion
76
adjacent to the central chamber
74
, and an internally threaded portion
77
adjacent to the widened end portion
76
. The widened end portion
76
receives an adjustable throttle member
80
which includes an externally threaded shank portion
81
received within the internally threaded portion
77
of the bore
75
, and a needle port ion
82
which co-operates with the orifice
72
. The shank portion
81
of the throttle member
80
is formed with slot
83
to receive the end of a screwdriver blade which can be inserted along the bore
75
, to enable the throttle member
80
to be rotated to adjust the axial position of the needle portion
82
relative to the throttle orifice
72
to provide a variable restriction.
When the passageways
67
are closed by the flexible seal
69
, communication between the two compartments of the cylinder
52
is only possible through passageways
70
,
71
and
73
, and the throttling orifice
72
. In this way, the orifice
72
serves as an adjustable throttle to regulate the flow of fluid from the outer compartment
66
to the inner compartment
65
as the cross-head
35
is driven inwardly of the actuator assembly by the compression springs
45
. The rate at which the door is closed under the force of the springs
45
can thus be adjusted, and it is particularly to be noted that such regulation is effective throughout the entire range of movement of the operating member
30
from the extended position shown in
FIG. 1B
to the retracted position shown in FIG.
1
A. However, on the reverse stroke, when the door is being opened, the flexible seal
69
is able to lift from the ends of the axial passageways
67
and allow relatively unrestricted flow of fluid between the two compartments.
The actuator assembly
20
further includes a pair of thrust assemblies
85
mounted on the shafts
28
disposed between the respective driving springs
45
and the damper assembly
50
.
As can best be seen from
FIGS. 6 and 7
an innermost end portion
86
of each shaft
28
is of slightly greater diameter than the outermost end portion
87
so as to form an outwardly facing shoulder
88
at the junction between the two portions. A groove
89
is formed around the narrower portion
87
of each shaft
28
at a predetermined spacing from the shoulder
88
.
The thrust assemblies
85
each include a thrust spring
90
located on the respective shaft
28
and within a cylinder
91
concentric with the shaft. Each cylinder
91
is fixed in a recess
92
formed in the intermediate boss of the cross-head
35
, and serves as a guide for the thrust spring
90
. The thrust springs
90
are strong compression springs having a rate greater than that of the coil springs
45
.
An internally widened end portion
93
of each cylinder
91
forms an outwardly facing shoulder
94
, and internally the widened end portion
93
is formed with a circumferential groove
95
at a predetermined spacing from the shoulder
94
. The arrangement is such that when the cross-head
35
abuts the stop plate
29
as shown in
FIG. 7
, the groove
95
in the cylinder
91
is longitudinally offset relative to the groove
89
formed in the shaft
28
, so as to be somewhat further from the mounting member
21
. The widened end portion
93
of each cylinder
90
is fitted with a retaining clip
96
.
A control mechanism
100
is provided whereby said thrust springs
90
are employed to augment the force of the driving springs
45
. The control mechanism includes in each cylinder
91
a carrier block
101
which is held in contact with the retaining clip
96
by engagement with the thrust spring
90
. As best seen in
FIGS. 8 and 9
, the carrier block
101
is formed with a central bore
102
whereby it is slidable on the narrower portion
87
of the shaft
28
. The carrier block
101
is also formed with two intersecting transverse bores
103
,
104
which contain four balls
105
in the respective radial arms thereof. The transverse bores
103
,
104
, balls
105
and grooves
89
and
95
are so dimensioned that the balls
105
may be displaced radially to seat in either the groove
89
formed on the shaft
28
, or in the groove
95
formed in the cylinder
91
.
As can be seen from
FIG. 7
, when the door closer is in its closed condition the balls
105
are located in the groove
89
formed in the shaft
28
, and they are held in this position by engagement of the balls
105
with the interior surface of the widened end portion
93
of the associated cylinder
91
at a point spaced outwardly from the groove
95
by a small distance. The balls thus act as a detent means which holds the carrier block
101
in a pre-determined position on the shaft
28
, in which position the carrier block is spaced from the shoulder
94
in the cylinder
91
and the thrust spring
90
is in a relatively extended condition.
As the door is opened, the cross-head
35
and cylinders
91
move outwardly (i.e. to the left as shown in
FIG. 7
) so that the thrust springs
90
are immediately compressed against the carrier blocks
101
, which are held in fixed positions on the shafts
28
by engagement of the balls
105
in the grooves
89
, since the balls
105
are held against outward displacement by engagement with the interior surface of the cylinders
91
.
However, the groove
95
in each cylinder
91
is so disposed relative to the shoulder
94
that when the shoulder
94
comes into engagement with the stationary carrier block
101
, the groove
95
is then in alignment with the transverse bores
103
,
104
in the carrier block
101
, thereby allowing balls
105
to move radially outwardly. Continued outward movement of the cylinder
91
can thus drive the carrier block
101
outwardly along the shaft
28
, and displace the balls
105
radially outwardly into the grooves
95
as shown in FIG.
6
.
As outward movement of the cylinder
91
continues, the balls
105
are held within the groove
95
by engagement with the exterior surface of the outermost portion
87
of the shaft
28
. At this time, the carrier block
101
is held in a fixed position relative to the cylinder
91
(i.e. against the shoulder
94
), by the detent action of the balls
105
in the grooves
95
, thereby holding the thrust springs
90
in a compressed condition, as shown in FIG.
6
.
As shown most clearly in
FIGS. 7 and 8
, the radial bores
103
,
104
are each of stepped form, with an internal shoulder
106
at the junction between an inner portion
107
, which is of such a diameter as to accommodate the ball
105
with minimum clearance, and a somewhat widened outer portion
108
. The shoulder
106
of each bore is spaced from the surface of the shaft
28
by a distance which is slightly less than the radius of the ball
105
. The effect of this is that the shoulder
106
assists in retaining the ball in the groove
95
while relieving the pressure exerted by the ball on the shaft
28
. This facilitates movement of the carrier blocks
101
along the shafts
28
by reducing friction, since the balls
105
are pressed laterally against the shoulder
106
as shown in
FIG. 9
in such a manner as to apply a radially outwardly directed force to the ball, thereby holding it in the groove
95
while at the same time relieving the pressure exerted by the ball on the shaft
28
.
In operation, the thrust springs
90
are initially in a relatively unstressed condition as shown in
FIG. 7
while the door is closed and are compressed during the initial stages of the opening movement of the door through a distance corresponding to movement of the shoulders
94
within the cylinders
90
into engagement with the carrier blocks
101
while the carrier blocks are held in fixed positions on the shafts
28
. The thrust springs
90
are then held in that compressed condition, as shown in
FIG. 6
, throughout the remainder of the movement while the carrier blocks
101
are held in fixed positions in the cylinders
91
and travel with the cylinders, along the shafts
28
.
When the door closes subsequently under the action of compression springs
45
, the carrier blocks
101
are initially retained in their fixed positions within the cylinders
91
, since the balls
105
continue to be held within the grooves
95
by the shaft
28
and the thrust springs
90
are maintained in their stressed condition. But when the transverse bores
103
,
104
of the carrier blocks
101
again come into register with the grooves
89
formed in the shafts
28
, some way before the door reaches its closed position, at this point the balls
105
are free to move radially inwardly into the grooves
89
, thereby moving out of the grooves
95
formed in the cylinders
91
, and releasing the cylinders relative to the carrier blocks
101
. The carrier blocks
101
are then held in a fixed position relative to the shafts
28
, and the thrust springs
90
, acting on the now fixed carrier blocks
101
exert an augmented driving force on the cross-head
35
over the final part of its range of movement as the shoulders
94
of the cylinders
91
move away from the carrier blocks
101
as shown in FIG.
7
.
The adjustment plate
12
enables the point at which the thrust springs
90
come into operation to be varied. Adjustment of the adjustment plate
12
relative to the mounting plate
11
of the anchor assembly
10
alters the angular position of the door at which the balls
105
become aligned with the grooves
89
in the shafts
28
by varying the spacing between the mounting plate
11
of the anchor assembly
10
and the cross-head
35
of the operating member
30
. In this way the fixed position of the grooves
98
corresponds to any selected position of the mounting plate
11
within a predetermined range of positions. Typically, the range of adjustment may be between 0 and about 15° of opening. Thus at one extreme, the thrust springs may be rendered ineffective if desired, whilst the range of angular movement over which they are effective, when required, can be set at up to 15° or thereabouts according to the precise geometry adopted.
This is illustrated in
FIG. 10
, in which the total force (F) exerted on the operating member
30
is shown relative to the angle of opening (α). As can be seen from the maximum angle of opening (α
max
) to an adjustable angle (α
x
) the force is at an ideally constant value (F
S1
). At the point (α
x
) the force increases sharply to an augmented value (F
S2
) and ideally remains at that value throughout the remainder of the range of movement to the position of closure represented by (α
0
). The angle (α
x
) may be varied between zero (α
0
) and typically about 15° as previously described.
In practice, the damper assembly
50
is, however, operative over the entire range of movement of the operating member
30
up to the “door closed” position to provide a controlled and adjustable rate of closure and thus a variable time to closure from any initial angle of opening as previously described, and the forces exerted by the closer are not constant during each part of the closing movement as illustrated in FIG.
10
. Thus in a typical embodiment with the main springs
45
fully compressed the closing force is initially 1040 Newtons (234 lbs.) whereas at approximately 16° opening angle and just prior to engagement of the thrust springs
92
the force is 612 Newtons (137 lbs.) whilst at 14° when the thrust springs have come into operation the force is increased to a total of 1308 Newtons (294 lbs.) of which 718 Newtons arises from the thrust springs.
The effect of the damper is illustrated in
FIG. 11
which shows the door closing speed (V) plotted against door closing time (T) from the position of maximum opening to closure, with minimum and maximum damping and an indication of the variable range of operation of the thrust springs.
With the damping set at minimum, and the action of the thrust springs set at maximum, the door speed follows the upper solid line curve (M), from which it can be seen that at time= to the door accelerates from rest to a uniform velocity V
1
and at time=t
1a
the thrust springs become effective with the result that the door speed increases to a higher velocity V
2
until at point A the door reaches its position of closure at time=t
2a
.
If the damping is set at the maximum value, the door speed follows the lower solid line curve (N) to a lower velocity V
3
and the thrust springs become effective at time=t
1b
following which the door speed increases to a value V
4
until at point B the door reaches its position of closure at time t=t
2b
.
However, if the thrust springs are rendered inoperative by appropriate adjustment of the plate
12
, when the damping is set at minimum the door continues to close at velocity V
1
as indicated by the broken line M′ until at point A′ it reaches its position of closure at time t=t
1c
whereas when the damping is set at maximum the door continues at velocity V
3
as indicated by broken line N′ until at point B′ it reaches its position of closure at time=t
2c
.
The shaded area bounded by points A, A′, B and B′ represents the envelope within which the closure time can be varied by the combined adjustments available by means of the adjustment plate
11
and the adjustable throttle incorporated in the damper assembly
50
.
Thus at all times during the closing action, the rate of movement of the door is controlled by the damper assembly
50
but, as illustrated in
FIG. 10
, the closing force applied by the driving springs
45
can be substantially augmented from F
S1
to F
S2
by the thrust springs
90
over a variable final part (α=α
x
to α
0
) of the closure movement, thus overcoming any resistance to closure which may be imposed by a latching mechanism operating between the door and door frame, but without the potentially excessive “snap action” associated with previous door closures of the kind in which the flow restriction imposed by the damper assembly is relieved during the final part of the closure movement. However, adjustment of the damper makes it possible to provide a controlled degree of snap action, when the flow restriction is set to a minimum, or a “soft” action, when die flow restriction is set to a maximum, or anything in between.
Adjustment of the position of the adjustment plate
12
of the anchor assembly
10
varies the effective length of the connection between the cross-head
35
and the anchor assembly, and can thus also enable the action of the thrust springs
90
to cut in at the correct point despite variations in the width of the gap between the inner edge of the door and the door flame in different installations.
The door closer as above described is fully adjustable with respect to the selected range of angular movement over which the augmented closure force is applied, and with respect to the degree of damping applied, whilst being particularly compact so that it can be installed in a door without compromising the fire resistance of the door.
The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.
Claims
- 1. A door closer comprising in combination:an anchor member (10) for mounting on a door frame, an actuator assembly (20) for mounting within the thickness of a door which is hinged for movement between open and closed positions relative to said door frame, an operating member (30) coupled by an articulated link (33) to said anchor member (10) and mounted in said actuator assembly (20) for a range of movement between a retracted position in which said anchor member (10) is held immediately adjacent to said actuator assembly (30) and an extended position in which said anchor member (10) is held in spaced relation to said actuator assembly (30), resilient driving means (45) arranged to exert a driving force on said operating member (30) in a manner such as to drive said operating member towards said retracted position and thereby draw said anchor member (10) and said actuator assembly (20) together such that, when installed, the door closer acts to draw the door into its closed position relative to the frame, a damper (50) connected to said operating member so as to control the rate of movement of the operating member (30) in at least a direction towards said retracted position, said damper comprising a cylinder (52) containing hydraulic fluid, a piston rod (27) carrying a piston (51) which divides the cylinder (52) into two chambers (65, 66), and flow-restricting means (70-83) to limit the rate of flow of hydraulic fluid from one of said chambers to the other at least in one direction of fluid flow in response to movement of said operating member towards said retracted position, an adjustable throttle, which comprises two elements (72, 82) in combination, the flow restriction imposed on the hydraulic fluid by said throttle being variable by relative positional adjustment of said two throttle elements, and an adjustment member (80) to enable one of said throttle elements to be positionally adjusted relative to the other so as to vary the flow restriction imposed on the hydraulic fluid by said throttle, resilient thrust means (85) arranged to exert an increased driving force on said operating member (30), control means (100) whereby said thrust means (85) is operative to apply said increased driving force to said operating member (30) over a defined part of said range of movement as said operating member (30) approaches said retracted position, corresponding to movement of the door over the final part of its movement into its closed position, and an adjustment member (12) operatively connected with said control means (100) to vary the point in the range of movement of said operating member at which said resilient thrust means (85) becomes operative to apply said increased driving force.
- 2. A door closer according to claim 1 wherein said control means (100) includes detent means (105) arranged to hold said thrust means (85) in a stressed condition over the whole of the range of movement of the operating member (30) apart from said defined part of said range.
- 3. A door closer according to claim 2 wherein said thrust means (85) includes a compression spring (90) located within a guide member (91) which is coupled to said operating member (30) and slidable therewith along a fixed shaft (28), and said detent means (105) is provided on a carrier member (101) which is retained within said guide member (91) to abut one end of said compression spring (90) and is slidable on said fixed shaft (28) and located within said guide member (91) for limited movement longitudinally thereof, the detent means (105) being engagable in an internal recess (95) formed within said guide member (91) to hold the compression spring (90) in a compressed condition, and being displaceable from a position of engagement with said internal recess (95) to release said compression spring (90) at a predetermined position along said shaft (28) so as to apply said increased driving force to said operating member (30).
- 4. A door closer according to claim 3 wherein said detent means (105) is displaceable from said position of engagement with said internal recess (95) in said guide member (91) into a position of engagement with an external recess (89) formed in said shaft (28) to hold said carrier member (101) in a predetermined position on said shaft (28).
- 5. A door closer according to claim 4 wherein said detent means comprises a plurality of balls (105) located in one or more transverse bores (103, 104) formed in said carrier member (101).
- 6. A door closer according to claim 5 wherein each of said balls (105) is of a diameter greater than the radial spacing between an exterior face of said shaft (28) and an interior face of said guide member (91) so that said balls (105) are either held by said shaft (28) in said internal recess (95) formed in said guide member (91) or by said guide member (91) in said external recess (89) formed in said shaft (28).
- 7. A door closer according to claim 6 wherein the bores (103, 104) in which the balls (105) are located are formed with a radially innermost portion (107) having a diameter such as to accept the ball with a slight clearance and a radially outermost portion (108) having a greater diameter, the two portions meeting at an internal shoulder (106) disposed at a spacing from the shaft (28) which is less than the radius of the ball (105).
- 8. A door closer according to claim 7 wherein said cylinder (52) of said damper (50) is moveable relative to said actuator assembly (20) and is coupled to said operating member (30), and said piston (51) is static.
- 9. A door closer according to claim 8 wherein said flow-restricting means (70-83) is incorporated into said piston (51) and piston rod (27), and said adjustment member (80) has an operating element (83) which is accessible from one end of said piston rod (27).
- 10. A door closer according to claim 9 wherein said adjustment member (80) comprises a shaft located within an axial bore (75) formed in said piston rod (27), with an external threaded formation (81) engaging an internal threaded formation (77) in the bore of the piston rod whereby rotation of the adjustment member (80) varies its axial position within said bore (75).
- 11. A door closer according to claim 10 wherein said adjustment member (80) is provided at one end with a needle formation (82) which comprises one of said throttle elements to co-operate with an orifice (72) defined by the other of said elements, and at its other end with a head formation (83) whereby the adjustment member (80) may be rotated.
- 12. A door closer according to claim 7 wherein said thrust means (85) includes one or more spring elements (90) having a higher rate than said resilient driving means (45).
- 13. A door closer according to claim 12 wherein both said driving means (45) and said thrust means (85) comprise one or more coiled compression springs (45, 90).
- 14. A door closer according to claim 13 wherein said thrust means (85) and said driving means (45) each comprise two spring elements (45,45: 90,90) which extend in side by side parallel relationship and disposed symmetrically relative to said damper means (50).
- 15. A door closer according to claim 14 wherein said thrust means (85) are disposed between said driving means (45) and said damper means (50).
Priority Claims (1)
Number |
Date |
Country |
Kind |
9904845 |
Mar 1999 |
GB |
|
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/GB00/00717 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO00/52291 |
9/8/2000 |
WO |
A |
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Foreign Referenced Citations (11)
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DE |
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DE |
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DE |
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Oct 1996 |
DE |
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Jul 1998 |
DE |
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Oct 1980 |
EP |
0332426 |
Sep 1989 |
EP |
2 566 827 |
Jan 1986 |
FR |
1497220 |
Jan 1978 |
GB |
2167121 |
May 1986 |
GB |
WO 9605397 |
Feb 1996 |
WO |