GB2302579A

GB2302579A - Vibration isolating platform

Info

Publication number: GB2302579A
Application number: GB9613082A
Authority: GB
Inventors: Mark Hicken
Original assignee: Audio Partnership PLC
Current assignee: Audio Partnership PLC
Priority date: 1995-06-22
Filing date: 1996-06-21
Publication date: 1997-01-22
Also published as: GB9613082D0; GB9512752D0

Abstract

A vibration isolating platform 1 comprises a tray-like base 2 stably supported on at least one resilient ground engaging member 3, preferably in the form of pads of a resilient foamed plastics material. A load supporting member 4 is supported on at least one resilient intermediate member 7, preferably in the form of semi-spherical domes of a resilient elastomeric material, which intermediate member is supported on the base 2, the elastic properties of the ground engaging member 3 and intermediate member 7 being different such that they are arranged to damp different, or at least partly different, frequency ranges of vibration. The base 2 may have an upturned lip or flange 6 and the load supporting member 4 a downturned flange 5, forming an enclosure within which electronic circuitry may be mounted, preferably to the base by means of further vibration dampers.

Description

TITLE: VIBRATION ISOLATING DEVICE DESCRIPTION The invention relates to an isolating device for protecting electronic and electro-mechanical apparatus from vibration.

It is known to mount sound reproducing equipment such as audio amplifiers, disc players and the like on vibration isolating devices to insulate the equipment from airborne and groundborne vibration and thus to improve the standard of sound reproduction. Known devices include platforms mounted on air springs and platforms mounted on "Sorbothane" feet. Sorbothane is a trade name for a soft elastomeric material with good self damping properties.

It is an object of the invention to provide a novel vibration isolating device.

According to the invention, an isolating device, e.g.

platform comprises a base supported on at least one resilient ground engaging member, and a load supporting member supported on at least one resilient intermediate member, which intermediate member is supported on the base, the elastic properties of the ground engaging and intermediate members being different. Thus the intermediate and ground engaging members may be arranged to damp different frequency ranges of vibration, so that the spectrum of expected vibrations is extended or better covered.

Preferably the at least one ground engaging member comprises a plurality of feet (e.g. four feet) of an opencell rubber or synthetic elastomer and the intermediate member comprises a plurality of strips or domes, spheres etc. of a closed cell rubber or synthetic elastomer. The feet may be substantially spherical in their initial, unweighted, shape. Suitable synthetic elastomers for the ground engaging members include slow recovery polyurethane foams and for the intermediate members include EPDM (ethylene-propylene-diene monomer) co-polymer blends, which have good absorption properties and recover slowly.

The base may be formed as a tray, e.g. of metal, with a surrounding upturned lip and the load supporting member may be a panel, e.g. of metal, with a downturned surrounding lip sized to enclose, but be spaced from, the upturned lip of the base. Thus the base and the load supporting member may be of steel.

The base and/or the load supporting member may be adapted to support electronic circuitry, e.g. a digital-toanalogue converter for use in association with electronic apparatus, e.g. a compact-disc player supported on the platform. The electronic circuitry is preferably mounted on vibration dampers on the base, e.g. extruded silicone rubber supports.

Thus the base may be formed with input and output connecting sockets to enable interconnection between the electronic apparatus supported on the platform, the electronic circuitry in the platform and electronic or other equipment, e.g. an amplifier and loudspeakers, positioned remotely from the platform.

The load supporting member may carry an indicator device, e.g. a light emitting diode, connected to the electronic circuitry on the base to indicate operation of the electronic circuitry.

The invention is diagrammatically illustrated, by way of example, in the accompanying drawings, in which: Figures 1 is a partly broken-away plan view of a first embodiment of a vibration isolating platform; Figure 2 is a rear view of the platform of Figure 1; Figure 3 is a side view of the platform of Figure 1; Figure 4 is a sectional side view of the platform of Figure 3, taken on the line A-A of Figure 1; Figure 5 is a partly broken-away plan view of a second embodiment of vibration isolating platform; Figure 6 is a rear view of the platform of Figure 5; Figure 7 is a side view of the platform of Figure 5, and Figure 8 is a sectional side view of the platform of Figure 7, taken on the line A-A of Figure 5.

In the drawings, and referring more particularly to the embodiment of Figures 1 to 4, a vibration isolating platform 1 for electronic apparatus and equipment, particularly high fidelity sound reproducing equipment, comprises a tray-like generally rectangular base 2 e.g.

steel sheet supported on a plurality of ground engaging members or feet 3 in the form of pads of a resilient foamed plastics material e.g. EPDM. As shown more particularly in Figure 2, the ground engaging members may have an initial, unloaded spherical shape, shown in dotted lines, which when loaded with the weight of the platform and the equipment supported thereon deforms to a flattened form shown in full lines. Preferably the ground engaging members are of an open-cell resilient elastomeric material such as polyurethane foam.

The base carries a load supporting member 4 in the form of a generally rectangular member, e.g. of steel sheet, having a downwardly extending lip or flange 5 around its periphery and which fits loosely over the correspondingly upturned peripheral lip 6 of the tray-like base 2 to form a box-like enclosure.

Between the base and the load supporting member are disposed a plurality of intermediate members 7 in the form of semi-spherical domes of a resilient elastomeric material, e.g. a closed-cell SBR/NR/EPDM material, the characteristics of which are chosen to be different from those of the ground engaging members to increase the spectrum of vibrations which can be absorbed by the platform. A suitable material is sold by Rubberlast (Britain) Ltd under reference RL25 E Black.

The load supporting member is prevented from removal from the base by means of screws 8 fixed into the base at the rear thereof, as shown in Figures 1 to 3, and which engage in slots 9 in the load supporting member, together with corresponding flanges 10 and slots 11 in the sides of base and load supporting member. It will be understood that in normal operation the screws and flanges do not make contact with the sides of the slots so that the base and the load supporting member are connected only through the intermediate members. One or more vibration damping pads may be fixed to the underside of the load supporting member as can be seen in Figure 4.

The embodiment of Figures 5 to 8 is generally similar to that described above but in this case the underside of the load supporting member and/or the upper face of the base may carry electronic circuitry to be protected against vibration, e.g. a pre-amplifier, electrically connected by flexible leads (not shown) to an array of input/output sockets 12 carried on the base as shown in Figure 6.

The invention thus provides novel platforms for isolating sensitive electronic components and circuitry from the undesirable effects of vibration.

Claims

1. A vibration isolating device comprising a base stably supported on at least one resilient ground engaging member, and a load supporting member supported on at least one resilient intermediate member, which intermediate member is supported on the base, the elastic properties of the ground engaging and intermediate members being different such that the intermediate and ground engaging members are arranged to damp different or at least partly different frequency ranges of vibration.

2. A vibration isolating device according to claim 1, wherein the at least one ground engaging member comprises a plurality of feet and wherein the intermediate member comprises a plurality of discrete members, one of the pair of members comprising the ground engaging member and the intermediate member being of an open-cell rubber or synthetic elastomer and the other of the pair of members being of a closed-cell rubber or synthetic elastomer.

3. A vibration isolating device according to claim 2, wherein the ground engaging member is of polyurethane foam and wherein the intermediate member is of an ethylene propylene diene monomer.

4. A vibration isolating device according to claim 2 or claim 3, wherein the feet are substantially spherical in shape in their unloaded condition.

5. A vibration isolating device according to any preceding claim, wherein the base is formed as a tray with a surrounding upturned lip and the load supporting member comprises a panel formed with a downturned surrounding lip sized to enclose the upturned lip of the base, the panel forming a load platform.

6. A vibration isolating platform according to any preceding claim, wherein the base and the load supporting member form an enclosure, and comprising electronic circuitry in the enclosure.

7. A vibration isolating device according to claim 6, wherein the electronic circuitry is mounted on vibration dampers on the base.

8. A vibration isolating device according to claim 6 or claim 7, wherein the base is formed with input and output connecting sockets electrically connected to the electronic circuitry to enable interconnection between electronic apparatus supported on the device and the electronic circuitry in the enclosure.

9. A vibration isolating device according to any of claims 6 to 8, comprising a visual indicator connected to the electronic circuitry in the enclosure to indicate operation of the electronic circuitry, the visual indicator being mounted on the load supporting member.

10. A vibration isolating device according to claim 1, substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 4 or 5 to 8 of the accompanying drawings.