GB2235722A

GB2235722A - Self closing hinge device

Info

Publication number: GB2235722A
Application number: GB8920012A
Authority: GB
Inventors: Roy Raymond Lontho
Original assignee: Hunter Douglas Industries BV
Current assignee: Hunter Douglas Industries BV
Priority date: 1989-09-05
Filing date: 1989-09-05
Publication date: 1991-03-13
Also published as: AU6198590A; NZ235112A; GB8920012D0; AU622047B2

Abstract

A self closing hinge device, for example for an insect screen door 10, comprises first and second hinge plates 12, 16 each provided with hinge lugs 14 and 18, 20 respectively pivoted together by a hinge pin 22 on which is rigidly mounted a spring 34 with an arm 36 for applying a closing torque to the door. The hinge pin 22 is moveable between a first and second axil positions. In the first position a key 30 engages in a key way formed in the hinge lug 20 to prevent the hinge pin from rotating whereby the torsion spring 34, 36 causes the door 10 to close. In a second position the key 30 is disengaged allowing the pin to rotate so that the spring action does not take place. The pin 22 is latched in its respective positions by a projection on the hinge plate 12 engaging respective grooves 54, 56. A spring cover 38 is provided. <IMAGE>

Description

SELF CLOSING HINGE DEVICE The present invention relates to a self closing hinge device for a pivotal member, such as a door.

It is often advantageous to have doors so that they are spring loaded to be moved to a closed position.

One particular example of this is a door in the form of an insect screen. It is, of course, important that the insect screen should remain closed for most of the time, to prevent the insects from coming into the room through the door opening. However, it would be advantageous to be able to make this self closing aspect of the hinge device selectively inoperable, so that the insect screen door may remain open when desired.

It is now proposed, according to the present invention, to provide a self closing hinge device comprising first and second hinge plates, cooperating hinge lugs on said first and second hinge plates, a hinge pin passing through said hinge lugs to allow said hinge plates to pivot relative to one another, said hinge pin being axially slidable in said hinge lugs between first and second positions, a torsion spring mounted rigidly on said hinge pin, an arm associated with said torsion spring in a position to bear against said first hinge plate or against a member secured thereto and a key and cooperating keyway rigidly formed on, or secured to, said hinge pin and to said second hinge plate respectively, or vice versa, said key and keyway lockingly engaging with one another in said first position of said hinge pin, but being disengaged in the second position thereof, whereby the arm causes said first hinge plate or the member secured thereto to be urged to a closed position, with the hinge pin in its first position, but free movement thereof can occur with the hinge pin in its second position.

With such a structure, it is possible readily to move the hinge pin to the second position which will render the closing effect of the spring inoperative. The key and keyway may take a number of different forms, but in a preferred construction the keyway comprises a non-circular recess in a hinge lug of said second hinge plate and said key comprises a cooperatingly shaped projection provided on one longitudinal end of said hinge pin.

The key and keyway advantageously are interengageable in a number of different rotational positions.

This enables the tension in the spring to be altered by changing which one of these rotational positions is selected.

The projection may be integrally formed on a manually operable head on one end of said hinge pin.

In one particular embodiment the recess and the projection are each hexagonal, this providing the possibility of inter-engaging them in different rotational positions and preferably the head is externally knurled to facilitate moving said hinge between its first and second positions.

In order to ensure that the hinge pin takes up one of its first and second positions and does not inadvertently move to the other, detent means are preferably provided releasably to maintain the hinge pin in each of the first and second positions. These may comprise axially spaced annular grooves or ridges formed on the hinge pin and a resiliently loaded detent engageable selectively on one of the grooves or ridges. In a preferred construction, the hinge plates and lugs are formed from a plastics material and said detent member comprises a tag cantilevered on one of said hinge plates.

The torsion spring may take a number of different forms but in a most convenient construction it comprises a helical coil wire spring wound around the hinge pin, one end of the wire forming the arm. With such a structure, it is advantageous for a spring cover to be provided to engage over the spring, said cover comprising a part cylindrical portion fitted over the coil, a first wing covering said arm, a second wing abutting the member to which the first hinge plate is secured and a part cylindrical boss surrounding said hinge pin and engaging axially in one end of a hinge lug of the second hinge plate.

In order that the present invention may more readily be understood, the following description is given, merely by way of example, reference being made to the accompanying drawings in which: Figure 1 is a schematic, exploded, perspective view of one embodiment of hinge device according to the invention and an associated hinged, insect screen door; Figure 2 is a front elevation of the second hinge plate of the device of figure 1; Figure 3 is an enlarged part section taken on the line III-III of figure 2; and Figure 4 is a section on the line IV-IV of figure 3.

Referring first to figure 1 there is illustrated therein an insect screen door 10 having secured thereto a first hinge plate 12 provided with a hinge lug 14.

Associated with the door frame (not shown) is a second hinge plate 16 having two hinge lugs 18, 20.

Passed upwardly through the apertures formed in the hinge lugs 14, 18, 20 is a hinge pin 22 provided with a head 24 which is secured to the hinge pin 22 via a bolt 26.

The head 24 includes an enlarged externally knurled body portion 28 and a hexagonal projection 30 forming a key. It will be seen from that the upper hinge lug 18 is provided with a hexagonal recess 32. The lower hinge lug 20 is provided with a similar recess (not shown) which is sized to receive the hexagonal projection 30 and act as a keyway for the key formed by this projection.

Rigidly mounted on the upper end of the hinge pin 22 is a helical coil wire spring which is wound around the hinge pin and one end 36 thereof forms an arm which is engageable with the door 10.

A spring cover 38 includes a part cylindrical portion 40 which can be fitted over the coil spring 34, a first wing 42 which covers the arm 36 of the spring and a second wing 44 which engages against the edge 11 of the door. A part cylindrical boss 46 is engageable in the recess 32 in the lug 18 of the second hinge plate 16.

The first hinge plate 12 is illustrated very schematically in figure 1, but it is shown in more detail in figure 2. It will be seen that the plate includes a cantilever arm 48 carrying, at its free end, a tag 50 which, it will be noted, extends over a portion of the cylindrical surface defined by the aperture 52 formed in the lug 14.

The tip of the tag can, however, be flexed downwardly, from the position seen in figure 4. Referring again to figure 1, it will be noted that the hinge pin 22 has two axially spaced annular grooves 54, 56. The tag 50 is selectively engageable in one of these grooves. Thus, in a first position, the tag 50 engages in the groove 54 and in a second position, which can be achieved by pulling down on the knurled surface 28 of the head 24, the tag 50 engages in the second groove 56.

It will be understood that in the first position, that is with the tag in the groove 54, the hexagonal projection 30 engages in the cooperating recess in the bottom of the hinge lug 20 of the second hinge plate 16. In this disposition, the pin 22 is prevented from rotating, so that the spring 34 and its arm 36 serve to move the door 10 to a closed position.

If the head 24 is pulled downwardly, however, the tag 50 will disengage from the groove 54 and will engage, in a second position of the hinge pin 22, in the groove 56. In this position, the hexagonal projection 30 is not engaged in the recess so the hinge pin can rotate freely and the spring will then not serve to close the door 10.

Claims

1. A self closing hinge device comprising first and second hinge plates, cooperating hinge lugs on said first and second hinge plates, a hinge pin passing through said hinge lugs to allow said hinge plates to pivot relative to one another, said hinge pin being axially slidable in said hinge lugs between first and second positions, a torsion spring mounted rigidly on said hinge pin, an arm associated with said torsion spring in a position to bear against said first hinge plate or against a member secured thereto and a key and cooperating keyway rigidly formed on, or secured to, said hinge pin and to said second hinge plate respectively, or vice versa, said key and keyway lockingly engaging with one another in said first position of said hinge pin, but being disengaged in the second position thereof, whereby the arm causes said first hinge plate or the member secured thereto to be urged to a closed position, with the hinge pin in its first position, but free movement thereof can occur with the hinge pin in its second position.

2. A device according to claim 1, wherein the key and keyway are inter-engageable in a number of different rotational positions.

3. A device according to claim 1 or 2, wherein said keyway comprises a non-circular recess in a hinge lug of said second hinge plate and said key comprises a cooperatingly shaped projection provided on one longitudinal end of said hinge pin.

4. A device according to claim 3, wherein said recess and said projection are each hexagonal.

5. A device according to claim 4, wherein said projection is integrally formed on a manually operable head on said one end of said hinge pin.

6. A device according to claim 5, wherein said head is externally knurled to facilitate moving said hinge pin between its first and second positions.

7. A device according to any preceding claim and further comprising detent means releasably maintaining said hinge pin in each of said first and second positions.

8. A device according to claim 6, wherein said detent means comprises axially spaced annular grooves or ridges formed on said hinge pin and a resiliently loaded detent engageable selectively with one of said grooves or ridges.

9. A device according to claim 8, wherein said hinge plates and lugs are formed from a plastics material and wherein said detent member comprises a tag cantilevered on one of said hinge plates.

10. A device according to any preceding claim, wherein said torsion spring is a helical coil wire spring wound around said hinge pin, one end of the wire forming said arm.

11. A device according to claim 10, and further comprising a spring cover engaged over said spring, said cover comprising a part cylindrical portion fitted over the coil, a first wing covering said arm, a second wing abutting the member to which the first hinge plate is secured and a part cylindrical boss surrounding said hinge pin and engaging axially in one end of a hinge lug of the second hinge plate.

12. A self closing hinge device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.