GB2350664A

GB2350664A - Noise reducing support member

Info

Publication number: GB2350664A
Application number: GB0013179A
Authority: GB
Inventors: Richard Gatley
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-06-01
Filing date: 2000-06-01
Publication date: 2000-12-06
Also published as: GB0013179D0; GB9912649D0

Abstract

Support member (30, figure 4) for the mounting assembly of an air pressure stabilising device (10) comprises an upwardly open slot 34 containing restraints 42, 44 to prevent noise producing movement. Support (30) is adapted, preferably by bores 32, to be fixed to a surface, preferably the opening of an air duct into an operating theatre. Restraints 42, 44 preferably comprise elastomeric shock absorbing elements projecting form bores (41, 43) in side walls 39 of slot 34 parallel to the axis of rotation of bearing element (18, figure 1) of device 10. Shock absorbers 42 may be integral with slot 34 or secured by adhesive and may form the bearing surface for and prevent upward movement of element (18). Restraining means may also be afforded by moulding support (30) from plastics such as nylon or acetal co-polymer. Device (10) is preferably provided with a stop pin (20) which acts upon divergent faces 36 of slot 34. Slot 34 may have re-entrant portions (62a, 62b, figure 7) to limit radial movement of element (18) and material 46, 48 removed from faces 36 to increase flexibility and dampen noise.

Description

2350664 Title: Mounting Device Desedpli This invention is concerned with

improvements relating to mounting devices, particularly but not exclusively to mounting devices for air pressure stabilising devices.

Conventionally it is the practice in a surgically clean environment to maintain an environmental pressure slightly above atmospheric pressure, to prevent possibly contaminated air from flowing into the environment, such as through gaps in doors, windows and the like. Conventionally used to control this pressure is an air pressure stabilising device mounted on a duct defining an opening, and a control member mounted in the opening for movement between open and closed positions, the control member being operative to move from its closed position in the event that pressure in the area under control rises above a predetermined level above atmospheric pressure, and to return to its closed position in the event that pressure falls below said predetermined levels.

In this way, pressure within the area under control may be retained at a desired level above atmospheric pressure.

Conventionally, the opening lies in a generally vertical plane, and a conventional air pressure stabilising device comprises a control member in the form of a generally flat plate which is mounted for pivotal movement about a horizontal axis which extends below the geometric centre line of the plate, but above the centre of gravity of the plate. In this manner an upper part of the plate above said axis presents to the area being controlled an area greater than that presented by the lower part of the plate. The location of the pivot axis in relation to the centre of gravity ensures that, at rest, the plate is retained in a closed position. However, as the pressure in the controlled area increases, the 2 excess force on the plate above the pivot axis causes the plate to move from its closed position, to vent the excess pressure.

Conventionally to provide a convenient mounting for the air pressure stabilising device, a mounting assembly is utilised which comprises two support members which may be mounted one either side of the opening in which the device is to operate, each comprising a downwardly- extending slot into which bearing elements of the device may be located, each slot comprising side walls which extend to a part-circular end face which conventionally provides a bearing surface for the bearing element.

Conveniently said side walls comprise an outer divergent region, providing convenient entry of the bearing element into position in engagement with said end face, and which similarly provide movement limiting means for the device. For example, the device may comprise a stop, conveniently in the form of a pin, spaced radially from the axis of the bearing, which may be engaged with the divergent side walls at either extreme of the desired movement of the device.

One problem encountered in conventional air pressure stabilising devices is that they rattle during operation, and particularly in a surgical environment, this rattling may be off-putting. For example, under certain forces the bearing element may ride upwardly within the slot, and subsequently fall back into engagement with the end face. Additionally, noise is created when the device moves to an extreme position, by engagement of the stop pin with one of the divergent side walls, and it is one of the various objects of this invention to provide a mounting means for an air pressure stabilising device which enables noise created during operation of the device to be reduced.

According to this invention there is provided a support member, for use as part of a mounting assembly of an air pressure stabilising device, said support member being adapted to be secured to a support surface bounding an opening into which the air pressure stabilising device is to be located, said 3 support member having an upwardly-open slot into which a bearing element of the device may be downwardly located, wherein the support member comprises means to restrain the bearing element against noise- producing movement in the slot.

For example, said means may be operative to restrain movement of the bearing element upwardly within the slot. Thus said means may comprise at least one formation extending into the slot which is resiliently deformable, to permit location of the bearing element in an operative position in engagement with a bearing surface for the bearing element.

If desired, said formation may provide a bearing surface, engageable by the bearing element, and which may generally provide a continuation of the bearing surface of the slot.

Conveniently, said formation is integral with the support member, or may be secured separately to the support member. For example, said means may be provided by shock absorbing elements mounted on the support member and extending through the side walls of the slot. For example, apertures may be provided which open into the side walls, conveniently said apertures being provided by bores parallel to the axis of rotation of the bearing element within the slot, said bores being spaced from the slot but being of a diameter such that the bores open into the slot.

Alternatively, the shock absorbing members may be secured within the slot by adhesive.

Alternatively or in addition, said means may be provided by the moulding of the support member from plastics material. Thus, some noisereducing effect is obtained simply by moulding the support member from a material such as an acetal co-polymer or nylon. Preferably however the shock absorbing member comprises additional noise-reducing means, conveniently of the kind set out in some at least of the last preceding paragraphs.

4 According to this invention there is provided a support member for the mounting assembly of an air pressure stabilising device, said support member being adapted to be secured to a support surface bounding an opening into which the air pressure stabilising device is to be located, said support member having an upwardly-open slot into which a bearing element of the device may be downwardly located, wherein said bearing element is seated against shock absorbing elements extending into the slot, said shock absorbing elements providing part at least of the bearing surface of the support member.

Alternatively or in addition where the control device comprises movement limiting means provided by a stop pin spaced radially from the axis of the bearing element, said means to restrain the bearing element against noise-producing movement in the slot may be operative to reduce noise created by engagement on the outer faces of the slot by the stop pin.

Thus, said means may be provided by shock absorbing means provided at said outer faces of the slot.

According to this invention there is also provided a support member for the mounting assembly for an air pressure stabilising device, said support member being adapted to be secured to a support surface bounding an opening in which the device is to operate, said support member comprising an upwardly-open slot into which a bearing element of the device may be downwardly located, wherein said bearing element is seated against shock absorbing elements extending into the slot, said shock absorbing elements providing the bearing surface of the support member.

Additional to the problem of noise created by operation of the conventional air pressure stabilising device, is a problem that when the stop pin engages particularly against divergent faces of the slot, forces are created which tend to cause the bearing element to ride upwardly within the slot. Whilst such forces are unlikely to cause the bearing element to move wholly outside the slot, if the air pressure stabilising device falls a large distance unnecessarily, jarring may create noise and damage irrespective of any shock absorbing capability.

According to this invention there is also provided a support member for use as part of a mounting assembly for an air pressure stabilising device, the support member being adapted to be secured to a support surface bounding an opening into which the air pressure stabilising device is to be located, said support member having a slot into which a bearing element of the device may be downwardly located, said slot comprising diverging faces which in conjunction with a stop pin provided on the air pressure stabilising device provide movement limiting means, characterised in that there is provided, at the end of each divergent face, a re-entrant portion which provides limiting means for limiting radial movement of the bearing element out of the slot.

Conveniently said re-entrant portion may comprise part-circular surfaces, and/or generally circumferential surfaces.

According to this invention there is also provided a mounting assembly for an air pressure stabilising device comprising a support member adapted to be secured to a support surface bounding an opening into which the air pressure stabilising device is to be located, said support member having an upwardlyopen slot into which a bearing element of the device may be downwardly located, wherein the support member is provided with shock absorbing means, extending into the slot.

Preferably the shock absorbing means comprises one or more members which extend into an end face of the slot, and/or one or more members which extend into side walls of the slot, and/or one or more members located adjacent to an outer region of the slot.

There will now be given a detailed description, to be read with reference to the accompanying drawings, of an air pressure stabilising device comprising a mounting assembly which is a preferred embodiment of this invention, said

6 mounting assembly having been selected for the purposes of illustrating the invention by way of example.

In the accompanying drawings:

FIGURE 1 is a side elevation showing part of the air pressure stabilising device which is the first embodiment of this invention; FIGURE 2 is an end elevation, taken in the direction A of figure 1; FIGURE 3 is a perspective view of the support member, also illustrative of the invention, of the first embodiment:

FIGURE 4 is an end elevation showing the second embodiment of the invention; FIGURE 5 is an end elevation showing the third embodiment of the invention; FIGURE 6 is an end elevation showing the support member which is the fourth embodiment of the invention; and FIGURE 7 is an end elevation showing the support member which is the fifth embodiment of the invention.

The air pressure stabilising device which is the first embodiment of this invention is similar in certain aspects to the specification of my international patent application GB98/03748, to which reference should be made for details of construction and operation not described herein.

The air pressure stabilising device which is the first embodiment of this invention comprises two control members 10, only one of which is shown in Figure 1, each comprising a slot 12 into which one edge portion of a damper 14 may be located, securing means 16 being provided to secure the damper in position within the slot 12. Each control member comprises an outwardlyextending bearing element 18 which in use is located within one of two support members 30 of a mounting assembly, said mounting assembly and the support members thereof being particularly illustrative of the invention.

7 Each support member 30 is generally disc-like in shape, comprising a bore 32 which enables the support member to be secured to surfaces bounding the opening into which the air pressure stabilising device is to be located. In conventional manner the member 30 comprises a downwardlyextending slot 34, comprising an outer section, having divergent faces 36, 37, a central portion 38, comprising generally parallel side walls 39, and an end face 40, which is part-circular, in particular semi-circular, providing a bearing surface of the support member.

In accordance with the invention, the support member 30 is provided with noise-reducing means, provided in the preferred embodiment particularly by the moulding of the support member of a convenient Plastics material, such as an acetal co-polymer, or of nylon. Thus, noise produced by movement of the bearing element 18 in the slot 34 will be reduced.

Additionally in the first embodiment the noise-reducing means comprises formations 42, 44 provided in the side walls 39 of the slot, said formations generally providing a continuation of the bearing surface 40 of the support member, as may be seen particularly from Figure 3. On assembly, movement of the bearing element 18 downwardly into the slot 34 causes the formations 42, 44 to be initially deformed, involving a degree of opening of the slot, and thereafter the formations pass behind the bearing element 18, trapping the bearing element against upward movement within the slot. Thus, major movement of the bearing element, and major noise production by virtue of this movement is significantly reduced.

The noise-reducing means of the first embodiment also comprises shock absorbing means in the outer regions of the slot 34, particularly in the vicinity of the outwardly-divergent faces 36 and 37. In the first embodiment, this is effected by the provision of through-extending slots 46, 48 provided adjacent to the divergent faces 36, 37, the effect of such removal making the faces 36 and 37 more flexible. In this manner, on severe rotation of the air pressure 8 stabilising device, limited by movement of the stop pin 20 into engagement with one or other of the surfaces 36 and 37, noise will be significantly attenuated, both by virtue of the support member being moulded from plastics material, and also by virtue of the flexibility provided by the slots 46 and 48.

In the air pressure stabilising device which is the second embodiment of this invention, shown in figure 4, in which similar numerals with the suffix a have been utilised, the support member is provided with two axial bores 41, 43 said bores being located adjacent the side walls 39a of the slot 34a, and opening into said side walls. The bores subtend an angle of approximately 270', and located therein are elongate members 42a and 44a of elastomeric material, conveniently rubber or plastics, effecting the functions similar to the formations 42 and 44 of the first embodiment.

The construction illustrated in Figure 4 is particularly suitable for use where the shock absorbing member 30 is of metal, but may of course be used where the shock absorbing member is moulded from plastics material.

In the shock absorbing member which is the third embodiment of this invention, as shown in Figure 5, in which similar numerals with the suffix b have been utilised, the noise-reducing means includes elongate elastomeric members 46b, 48b, similarly located in axial bores 45b, 47b provided in the support member 30 adjac ent to the divergent faces 37b. The bores 45b, 47b extend in the axial direction, and similarly subtend an angle of about 270% opening through the divergent faces 37b.

Thus, whilst the elements 42a, 44a of the second embodiment are conveniently of elastomeric material, in the third embodiment conveniently the elements 46b and 48b are in the form of hollow tubes, so located that, as rotation of the control member 10 occurs, the stop pin 20 projecting from the outer end face of the control member will engage one or other of the shock absorbing members 46b, 48b, reducing impact noise.

9 In the air pressure stabilising device which is the fourth embodiment of this invention, shown in Figure 6, in which similar numerals with the suffix c have been utilised, in addition to formations 42c, 44c corresponding to the formations 42, 44 of the first embodiment, and shock absorbing elements 46c, 48c corresponding to the shock absorbing elements 46b, 48b of the fourth embodiment, additional shock absorbing elements 52, 54 are incorporated, being located in bores 51, 53 extending axially through the support member spaced a short distance from the bearing surface 40c, said bores 51, 53 similarly opening into the slot 34c, such that the shock absorbing elements 51, 53 protrude into the slot. In this way the bearing element 18, when downwardly located in the slot, and passed beyond the formations 42c, 44c, engage with the shock absorbing elements 52, 54, similarly constraining relative movement between the bearing element 18 and the support member 30, and reducing noiseproducing relative movement.

In a fifth embodiment of this invention, shown in Figure 7, in which similar numerals with the suffix d have been utilised to indicate similar parts, the divergent faces 37d terminate in part-circular portions 60a, 60b, within which the stop pin 20 may be engaged, reducing or eliminating tendency for vertical movement to occur between the control member 10 and the support members 30.

Conveniently, re-entrant portions 62a, 62b are provided, which extend generally in the circumferential direction, to prevent excessive radial movement of the pin.

In the present specification "comprise" means %ncludes or consists of' and "comprising" means %ncluding or consisting of'.

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 support member, for use as part of a mounting assembly of an air pressure stabilising device, said support member being adapted to be secured to a support surface bounding an opening into which the air pressure stabilising device is to be located, said support member having an upwardly-open slot into which a bearing element of the device may be downwardly located, wherein the support member comprises means to restrain the bearing element against noiseproducing movement in the slot.

2 A support member according to claim 1 wherein said means is operative to restrain movement of the bearing element upwardly within the slot.

3 A support member according to claim 2 wherein said means comprises at least one formation extending into the slot which is resiliently deformable to permit location of the bearing element in an operative position.

4 A support member according to claim 3 wherein said formation provides a bearing surface, engageable by the bearing element, which generally provides a continuation of a bearing surface of the slot.

A support member according to one of claims 3 and 4 wherein said formation is integral with the support member.

6 A support member according to any one of claims 1 to 4 wherein said means comprises shock absorbing elements mounted on the support member and extending through side walls of the slot.

12

7 A support member according to claim 6 wherein said shock absorbing elements provide bearing surfaces in the slot for said bearing element.

8 A support member according to claims 6 and 7 provided with apertures which open into the side walls, the shock absorbing elements being located in said apertures and projecting therefrom through the side walls.

9 A support member according to claim 8 wherein said apertures are provided by bores extending through the support member parallel to the axis of rotation of the bearing element within the slot, said bores being spaced from the slot but being of a diameter such that the bores open into the slot.

A mounting assembly according to claim 7 wherein the shock absorbing members are secured within the slot by adhesive.

11 A support member according to any one of the preceding claims wherein said means is afforded by the moulding of the support member from plastics material.

12 A support member according to claim 1 wherein said means is provided by removing material from the support member in the vicinity of the slot, to provide the surface of the support member which bounds the slot with greater flexibility.

13 A support member for the mounting assembly of an air pressure stabilising device, said support member being adapted to be secured to a support surface bounding an opening into which the air pressure stabilising device is to be located, said support member having an upwardly-open slot into which a bearing element of the device may be downwardly located, wherein 13 said bearing element is seated against shock absorbing elements extending into the slot, said shock absorbing elements providing part at least of the bearing surface of the support member.

14 A support member according to any one of the preceding claims wherein said shock absorbing means is provided at said outer faces of the slot.

A support member for the mounting assembly of an air pressure stabilising device, said support member being adapted to be secured to a support surface bounding an opening in which the device is to operate, said support member comprising an upwardly-slot into which a bearing element of the device may be downwardly located, wherein said bearing element is seated against shock absorbing elements located in the slot, said shock absorbing elements providing the bearing surface of the support member.

16 A support member for use as part of a mounting assembly of an air pressure stabilising device, the support member being adapted to be secured to a support surface bounding an opening into which the air pressure stabilising device may be located, said support member having a slot into which a bearing element of the device may be downwardly located, said slot comprising diverging faces which in conjunction with a stop pin provided on the air pressure stabilising device provides movement limiting means, characterised in that there is provided, at the end of each divergent face, a re-entrant portion which provides limiting means for limiting radial movement of the bearing element out of the slot.

17 A support member according to claim 16 wherein said re-entrant portion comprises part-circular surfaces and/or generally circumferential surfaces.

14

18 A mounting assembly for an air pressure stabilising device comprising a support member adapted to be secured to a support surface bounding an opening into which the air pressure stabilising device is to be located, said support member having an upwardly-open slot into which a bearing element of the device may be downwardly located, wherein the support member is provided with shock absorbing means, extending into the slot.

19 A mounting assembly according to claim 18 wherein said shock absorbing means comprises one or more members which extend into an end face of the slot.

A mounting assembly according to one of claims 18 and 19 wherein said shock absorbing means comprises one or more members which extend into side walls of the slot.

21 A mounting assembly according to any one of claims 18, 19 and 20 wherein said shock absorbing means comprises one or more members located adjacent to an outer region of the slot.

22 An air pressure stabilising device comprising a control member comprising bearing elements and a mounting assembly by which the control member may be mounted in the opening in which the device is to operate, the mounting assembly comprising two support members adapted to be mounted one either side of the opening, each support member being in accordance with any one of the preceding claims.

23 A support member for an air pressure stabilising device, constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.

24 A mounting assembly constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.

An air pressure stabilising device constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.

26 Any novel feature or novel combination of features hereinbefore described and/or shown in the accompanying drawings.