This application claims priority to British Patent Application No. 0504631.3, filed Mar. 5, 2005, which is incorporated herein by reference.
Door closers of the kind incorporating chains are generally designed to operate between the hinged side edge of the door leaf and the door jamb such that they are concealed when the door is closed and relatively inconspicuous when the door is open. Closers of this kind comprise a small plate link chain that is connected between the door and the door frame and is designed to be under tension so as to urge the door to a closed position. The chain is typically anchored at one end to the door frame by an end plate that is screwed to the door jamb. The other end of the chain is received in a cylindrical housing that is fixedly disposed in a bore in the door leaf. The chain is connected to the housing via a tension coil spring that serves to bias it into the housing in order to pull the door closed.
The chain in closers of this kind comprises a plurality of interleaved link plates that are interconnected by transverse, parallel pins at overlapping portions of the plates so that the links can pivot about the longitudinal axis of the pins.
The present application includes apparatus and methods for providing an improved door closer.
Various embodiments of the present invention pertain to improvements for door closing devices.
One embodiment of the present invention includes a door closer device which includes a chain connected to a housing and adapted to connect to the door frame or the door leaf; and a biasing member acting between the chain and the housing so as to urge the chain into the housing.
In yet another embodiment, the chain includes a plurality of pivotally connected links with a pair of adjacent links being adapted to come into abutment.
In a further embodiment, there is a door closer device which includes a chain having an end that is connected to the housing and an end adapted to connect to the other of the door frame or the door leaf; and a biasing member acting to urge the chain into the housing. The chain includes a plurality of pivotally connected inner and outer links, the outer link plates having a height less than that of the inner link plates.
These and other objects and advantages of the invention will be apparent from the following description, claims, and drawings.
a to 3c show exemplary chain link plate embodiments that can be used in the door closer device of the present invention;
a and 4b show front and end views of inner and outer link plates of one embodiment of the a door closer chain;
c is a diagrammatic representation of the door closer chain of
a to 5d illustrate further alternative configurations of the link plates of the door closer chain of the present invention.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
The present invention relates to a door closer device for assisting in moving a door leaf from an open to a closed position relative to a supporting door frame.
An example of a prior art door closer using a roller chain is illustrated in
One alternative design tries to mitigate this problem by limiting the amount of articulation of a given link relative to the next in one direction. This ensures that the chain forms an arc similar to that of the door path and therefore does not foul the door in normal use.
A further drawback of chain-operated door closers is that since a chain supports only tensile forces, it does not serve to constrain the motion of the door towards the closed position. For example, if there were an external force, such as a gust of wind, then the chain would buckle and allow the door to swing rapidly to the closed position. It will be apparent that this is potentially dangerous as the closing door may have significant momentum that is directed into the path of users. In the case of the chain with limited articulation such as that described above, the chain has a tendency to kink when the door is forced to the closed position. This can result in the closer mechanism becoming fouled as the edges of the chain links hit the edges of the housing. The contact between the chain links and the housing will cause the door to stop suddenly. Since the door can have significant momentum as it is forced shut sometimes the magnitude of the force involved is large enough to cause failure of the hinges or damage the door.
Other chain-operated door closers use a leaf chain in which identical link plates are interleaved across the full width of the chain and interconnected on transverse pins. These suffer from the same drawbacks as those described above.
It is an object of the present invention to obviate or mitigate the aforesaid disadvantages.
According to a first aspect of the present invention there is provided a door closer device for connection between a door leaf and a door frame, the closer device comprising a housing for receipt in one of the door leaf or the door frame, a chain defining a longitudinal axis and having a first end that is connected to the housing and a second end adapted to connect to the other of the door frame or the door leaf, and a biasing member acting between the chain and the housing so as to urge the chain into the housing, the chain comprising a plurality of pivotally connected links each having a pair of opposed side edges arranged such that a side edge of a link faces a corresponding side edge of an adjacent link, each side edge defining a first portion and a second portion, the facing first portions of adjacent links being adapted to come into abutment when the links are arranged such that the longitudinal axis of the chain extends substantially in a straight line so as to prevent the links from pivoting in a first direction, and facing second portions of adjacent links being adapted to come into abutment when the links are pivoted in a second direction opposite to the first direction such that the articulation is limited and the links describe a line that substantially follows an arc.
The arrangement of the links is such that their pivotal movement is restricted so as to limit the degree of “bending” of the chain as a whole. The door closer chain has a limited degree of bending in one direction so that it describes a curve when the door leaf is opened in that direction and an anti-back bend feature to prevent the door leaf opening in the other direction and to prevent cranking of the chain under an external load that tends to close the door. This serves to reduce the risk of the chain rubbing against the housing and also prevent the chain from being damaged in the event that an external force is applied to close the door.
The chain links may be interconnected by a plurality of transverse pins that pass through apertures in the links. The longitudinal axis extends in parallel to the imaginary line between the centres of the pins.
The apertures are ideally formed in overlapping parts of the links.
The first end of the chain is preferably connected to the housing via said biasing member. The connection may be to a closed end of the housing.
The biasing member may be a spring, preferably a coiled tension spring.
The housing is preferably disposed in a bore in the door.
The housing preferably defines a bore in which said first end of the chain is received. The biasing member is also preferably received in the housing bore.
The first portions of the side edge of the chain links may be disposed normal to the longitudinal axis of the chain. Although in alternative embodiments they may be inclined to the normal at an acute or obtuse angle. The facing first portions preferably have complementary inclinations so that the links are prevented from pivoting in said first direction when the longitudinal axis of the chain extends substantially in a straight line. The first portions may be rectilinear or may be arcuate.
The second portions are preferably inclined to the normal to the longitudinal axis of the chain. The facing second portions being incline in opposite directions.
The chain links further comprise back edges that extend between said first portions of the side edges and front edges that extend between the second portions of the side edges. The back and front edges may be wholly or partially arcuate or straight.
The chain preferably comprises inner and outer links, the outer links being of reduced height compared to the inner links. The outer links are preferably thicker than the inner links. The links are ideally in the form of plates.
According to a second aspect of the present invention there is provided a door closer device for connection between a door leaf and a door frame, the closer device comprising a housing for receipt in one of the door leaf or the door frame, a chain defining a longitudinal axis and having a first end that is connected to the housing and a second end adapted to connect to the other of the door frame or the door leaf, and a biasing member acting between the chain and the housing so as to urge the chain into the housing, the chain comprising a plurality of pivotally connected inner and outer links, the outer link plates having a height less than that of the inner link plates.
This arrangement provides for greater clearance between the chain and the housing.
The outer link plates are preferably thicker than the inner link plates.
The housing preferably defines a bore into which the chain is urged.
The chain links may be interconnected by a plurality of transverse pins that pass through apertures in the links. The longitudinal axis extends in parallel to the imaginary line between the centres of the pins.
The apertures are ideally formed in overlapping parts of the links.
The first end of the chain is preferably connected to the housing via said biasing member. The connection may be to a closed end of the housing.
The relationship between the inner and outer links preferably accords to the following formula:
h1=a.h2
t2=a2.t1
where h1 is the height of the inner link plate, t1 is the thickness of the inner link plate, h2 is the height of the outer link plate, t2 is the thickness of the outer link plate, and a is a constant in the range 1.1 to 1.5.
Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings.
Referring now to
The chain has a plurality of interleaved inner and outer flat link plates 20, 19. Each of the link plates has two spaced pin apertures 23 (
The periphery of each link plate 19, 20 defines back, front and side edges 25, 26, 27 and it is the shape of the latter that is designed to govern the behaviour of the chain during articulation. As can be seen in
The arrangement allows the door to be opened through an angle of 180° with the pivoting action of the chain links continuing to be restricted so that the chain follows an arcuate path and for the closer to be effective.
The side edges 27 of the link plates 19, 20, shown in more detail in
The second portions 27b on the side edges of adjacent links allow only limited bending of the chain in the opposite direction before they come into abutment (as shown in
It will be appreciated that the profile of the chain links can be varied and the same result can still be attained. For example, the closer chain may comprise link plates having a shape shown in
An alternative chain link profile is illustrated in
The dimension of the outer and inner link pates is as follows:
h1=a.h2
t2=a2.t1
For a general design a=1.1-1.5
For an optimum design a=1.3
For any of the designs described above the shape of the back and/or front edges 40, 41 of the plates may be curved to follow the arc described by the chain as shown in
It will be appreciated that numerous modifications to the above described design may be made without departing from the scope of the invention as defined in the appended claims.
While the inventions have been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
Number | Date | Country | Kind |
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0504631.3 | Mar 2005 | GB | national |