GB2199362A

GB2199362A - Access panel locking arrangement

Info

Publication number: GB2199362A
Application number: GB8626989A
Authority: GB
Inventors: William Horace Tooth
Original assignee: Woodward & Barugh Ltd
Current assignee: Woodward & Barugh Ltd
Priority date: 1986-11-12
Filing date: 1986-11-12
Publication date: 1988-07-06
Also published as: GB8626989D0

Abstract

An access panel 1 is locked in position by means of a plurality of catches 4 adjacent the periphery of the panel. Each catch has a detent movable between a projecting position in which the detent can engage a peripheral frame surrounding an opening in which the panel is to be locked in position, and a retracted position. There is a locking mechanism incorporating a rotatable means operable from the exterior of the panel to rotate gear 6. This rotary movement is converted into linear movement in two members 11 extending in opposite directions. These members are connected by cam and cam follower means to further lateral extending members 14 which are each connected, again by means of a cam and cam follower 16 arrangement to a catch on one side of the panel and by means of a direct connection 15 to the catch on another side of the panel. <IMAGE>

Description

Description of Invention "Improvements in or relating to a locking arrangement" THE PRESENT INVENTION relates to a locking arrangement and more particularly relates to a locking arrangement which can be utilised to lock an access panel or door in position within a surrounding peripheral frame.

It is often necessary to secure an access panel- securely in position, and this is a particular requirement if the access panel is to form part of a housing which contains sensitive electrical equipment. The access panel, in such a case, must be retained securely in position, so that the panel is in electrical contact with the rest of the housing, to ensure that the housing constitutes a complete "Faraday cage" surrounding the electrical equipment.

Also, of course, it is desirable for the panel to be a substantially air tight fit thus minimising the ingress of air into the housing, since such air may well carry pollutants into the housing.

Access panels have, of course, been utilised before, and some access panels have been retained in position by means of locking catches which can each be moved from a retracted post ion to an extended position, the catches being located on all four sides of the panel so as to retain the panel securely in position. However, previously proposed arrangements of this type have utilised relatively complex mechanisms to drive the catches into the extended or projecting position, making the panels combersome and heavy.

According to this invention there is provided a locking arrangement for an access panel or the like said locking arrangement comprising a plurality of catches located adjacent the periphery of the panel, each catch having a detent movable between a projecting position in which the detent can engage a peripheral frame surrounding an opening in which the panel is to be locked in position, thus locking the panel in position, and a retracted position in which the panel may be removed from the peripheral frame, the locking mechanism incorporating a rotatable means operable from the exterior of the panel, means for converting the rotary movement into linear movement of two movement transmitting members extending in opposite directions, the movements being in opposed directions, the said movement transmitting members being connected by cam and cam follower means to further laterally extending movement transmitting members, the said further movement transmitting members each being connected by means of a cam and cam follower arrangement to a catch on one side of the panel and by means of a direct connection to a catch on a side of the panel extending orthogonally to said one side of the panel.

Preferably said rotatable means comprise a rotatable manually operable handle.

Conveniently said rotatable means drive a small gear wheel which engages a relatively large gear disc, said gear disc being interconnected by means of a cam and cam follower arrangement with said opposed movement transmitting members.

Advantageously said gear disc defines arcate cam slots cooperating with cam followers mounted on the said two movement transmitting means.

Preferably the said two opposed movement transmitting means are provided with cam followers engugeable with inclined cam slots formed in the laterally extending movement transmitting members.

Conveniently the laterally extending movement transmitting members are provided with cam slots which cooperate with cam followers provided on the latches provided on the respective said one edge of the panel.

Advantageously the movement transmitting members are guided by means of rollers.

Preferably latching means are provided to latch the locking arrangement in the locked position.

Conveniently means comprises a spring biassed latch member having a detent adapted to engage in a recess provided with a rotatable member when the rotatable member has rotated in such a position that the said detents are in the fully extended position.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure I is a perspective view of the front face of a panel incorporating a locking arrangement in accordance with the invention; and Figure 2 is a perspective view of the rear face of the panel.

Referring now to the drawings a locking arrangement in accordance with the invention is illustrated and mounted on a rectangular access hatch or panel I, which is of rectangular configuration. The front face of the access panel is provided with an actuating handle 2 which can be rotated to drive the locking arrangement from the locking position to the release position and vice-versa, and a retaining catch actuating lever 3 which can be operated to actuate a retaining catch which serves to retain the locking arrangement in the locking position.

Turning now to Figure 2 of the drawings it can be seen that the rear face of the panel I is provided with a peripheral recess 2 which can contain an appropriate sealing member, or which can cooperate with a sealing member.

Mounted on the panel are a plurality of catches 4 which are located adjacent the periphery of the panel I. In the illustrated embodiment there are two catches 4 provided on each side of the panel. Each catch includes a locking detent which can be driven outwardly, the detent being adapted to engage part of a frame defining a recess in which the panel I may be locked in position. The arrangement is thus such that as the locking detents are driven outwardly the panel is locked in position, but when the locking detents are withdrawn nwardly the panel may be removed to provide access.

The locking arrangement will now be described.

The handle 2 is mounted so that rotation of the handle 2 causes rotation of a small gear wheel 6, contained within a housing 7 on the rear face of the panel. The small gear wheel 6 engages the toothed periphery of a large gear disc 8. Two symmetrically located cam slots 9 are formed in the gear disc 8, and each slot is associated with a cam follower 10 which is mounted on a respective movement transmitting member II. The movement transmitting members extend away from the centrally located gear disc 8 in opposed directions, and the arrangement is such that rotation of the gear disc4n the clockwise direction causes the members II to be drawn in towards one another, and rotation in the anti-clockwise direction causes the members II to be driven outwardly away from each other.

Each of the members II terminates in a "T" shaped head, the head carrying two downwardly directed cam followers 12. The cam followers are located in inclined cam slots 13 formed in laterally extending movement transmitting members 14. Thus the arrangement is such that movement of the main force transmitting members II move inwardly and outwardly causes a corresponding inward and outward movement of the laterally extending movement transmitting members 14. A free end of each movement transmitting member 14 is provided with a projection 15 that engages a catch 4 formed on the side edge of the panel, whereas at an intermediate point on the movement transmitting member 14 is a further cam slot 16 which engages a cam follower formed on a catch 4' formed on the lower or upper edge of the panel. Thus each laterally extending movement transmitting member is associated with catches on two orthogonally extending sides of the panel.

It will thus be understood that rotation of the central gear disc 8, by means of actuation of the handle 2, will cause the movement transmitting members II to move inwardly or outwardly, with a corresponding inward or outward movement of the laterally extending movement transmitting members 14, this movement causing the two catches associated with each movement transmitting member 14 to move inwardly or outwardly.

Thus all the catches 4 and 4' can be caused to move inwardly and outwardly simultaneously without the provision of a complicated mechanism.

The gear disc II defines a notch or recess 17 which receives a detent provided on a spring biassed latch 18. The arrangement is such that the recess 17 is aligned with the detent when all the latches have been moved to the fully extended position. The latch is connected to a latch actuating lever 3 provided on the front face of the panel and thus the latch may be removed from the recess when it is desired to release the catches provided on the panel from the peripheral frame in which the panel is mounted.

It is to be appreciated that the disc and the movement and force transmitting members II and 14 are refabricated of a light weight material, 'and may be provided with perforations to reduce the weight of material utilised.

Thus a panel in accordance with the invention may be made to be very light, facilitating the use of the panel, for example, in helicopters or the like.

The various force of movement transmitting members may be guided by rollers 19 provided on the catches and at various other positions on the panel.

The catches utilised may each include a detent which is spring biassed away from the part of the catch which is driven by the described locking mechanism. The part of the detent which engages the surrounding frame may be inclined, and thus if a particular catch experiences a resistance to movement towards the latching position, the spring biassing the detent into the latching position will become compressed. Eventually all the catches will be biassed into the latching position by virtue of compression of the springs, and thus each latch will exert substantially the same force on the peripheral frame, ensuring that the panel exerts a substantially uniform force over the entire length of the seal received in the recess 4 provided in the panel.

Whilst one embodiment of the invention has been described many modifications may be effected to the described embodiment without departing from the spirit of the invention as claimed in the following claims.

For example a relatively large number of locking catches may be provided driven by a locking mechanism, and this may be necessary If a large excess latch is provided with a locking mechanism in accordance with the invention.

It is to be understood that the described embodiment of the invention forms a panel which can be mounted in position in a housing. It is envisaged that when the panel has been positioned in the housing, the panel will prevent any R.F. frequency radiation escaping from the housing.

Claims

CLAIMS:

I. A locking arrangement for an access panel or the like said locking arrangement comprising a plurality of catches located adjacent the periphery of the panel,. each catch having a detent movable between a projecting position in which the detent can engage a peripheral frame surrounding an opening in which the panel is to be locked in position, thus locking the panel in position, and a retracted position in which the panel may be removed from the peripheral frame, the locking mechanism incorporating a rotatable means operable from the exterior of the panel, means for converting the rotary movement into linear movement of two movement transmitting members extending in opposite directions, the movements being in opposed directions, the said movement transmitting members being connected by cam and cam follower means to further laterally extending movement transmitting members, the said further movement transmitting members each being connected by means of a cam and cam follower arrangement to a catch on one side of the panel and by means of a direct connection to a catch on a side of the panel extending orthogonally to said one side of the panel.
2. A locking arrangement according to claim I, wherein said rotatable means comprise a rotatable manually operable handle.
3. A locking arrangement according to claim I or claim 2 wherein said rotatable means drive a small gear wheel which engages a relatively large gear disc, said gear disc being interconnected by means of a cam and cam follower arrangement with said opposed movement transmitting members.
4. A locking arrangement according to claim 3, wherein said gear disc defines arcate cam slots cooperating with cam followers mounted on the said two movement transmitting means.
5. A locking arrangement according to any one of the preceding claims wherein the said two opposed movement transmitting means are provided with cam followers engageable with inclined cam slots formed in the laterally extending movement transmitting members.
6. A locking arrangement according to any one of the preceding claims wherein the laterally extending movement transmitting members are provided with cam slots which cooperate with cam followers provided on the latches provided on the respective said one edge of the panel.
7. A locking arrangement according to any one of the preceding claims wherein the movement transmitting members are guided by means of rollers.
8. A locking arrangement according to any one of the preceding claims wherein latching means are provided to latch the locking arrangement in the locked position.
9. A locking arrangement according to claim 8, wherein the latching means comprises a spring biassed latch member having a detent adapted to engage in a recess provided with a rotatable member when the rotatable member has rotated in such a position that the said detents are in the fully extended position.
10. A locking arrangement according to any one of the preceding claims mounted on an inspection hatch or panel.
I I. A locking arrangement substantially as herein described with reference to and as shown in the accompanying drawings.
12. Any novel feature or combination of features disclosed herein.