GB1602014A

GB1602014A - Noise reducing enclosure

Info

Publication number: GB1602014A
Application number: GB1347778A
Authority: GB
Original assignee: Metal Box PLC
Current assignee: Crown Packaging UK Ltd
Priority date: 1978-04-06
Filing date: 1978-04-06
Publication date: 1981-11-04

Description

(54) NOISE REDUCING ENCLOSURE (71) We, METAL BOX LIMITED, of Queens House, Forbury Road, Reading RG1 3JH, Berkshire, a British Company, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to an enclosure for a machine and more particularly but not exclusively to a noise reducing enclosure to contain the noise emitted by a press working sheet metal.

Presses are inspected regularly to ensure their mechanical efficiency and safety. However, when working sheet metals at high speeds, presses emit noise which may induce deafness in operators who spend prolonged periods of time near the presses. One known enclosure used to reduce the noise around such presses, is described in British Patent Application 190/76 (Specification No. 1,532,892). This known enclosure consists of a rigid frame onto which are fixed panels of acoustic barrier material. Doors are provided at various locations in the walls of the enclosure to permit access to parts of the press which require regular attention. For example a pair of doors is provided to give access to the press tools.

Also apertures are provided through which services, to the press, are passed such as electricity cables and pipes carrying compressed air. However, whilst this known enclosure provides a useful noise barrier, there is a need for a means to even greater access to the press so that major overhaul is not made difficult.

In a first aspect this invention provides a noise reducing enclosure adapted to enclose noise emitting apparatus and contain noise therefrom, stand upon the ground and guard people from mechanical risk and noise: the enclosure comprising an upright portion having means for fixing it to the ground floor and a hollow movable portion having sealing means to make an acoustic seal with the ground and means for acoustic sealing engagement between the upright portion and the movable portion.

In one embodiment the upright portion is substantially planar and vertical and the hollow movable portion has a roof portion and at least one side wall portion.

The upright portion may provide at least a first support for means to move the movable portion away from the upright portion to permit access into the enclosure.

In a preferred embodiment the enclosure has at least a second support means behind the movable portion and at least one beam, said beam extending from the second support means across the movable portion to the up right portion which provides a first support means for the beam, said movable portion being suspended from said beam during move ment thereof.

The enclosure may be provided with at least one aperture in the upright portion, through which aperture the needs of any apparatus therein may be supplied. Doors may also be provided in the enclosure to permit access to any parts of apparatus therein which require frequent attention.

In a second aspect the invention provides an enclosure according to the first aspect when standing upon the ground around apparatus capable of emitting noise. Sealing means is preferably provided to seal the moveable portion to the ground when the movable portion is in the closed position.

The apparatus is preferably isolated from the ground by antivibration means in a pit in the ground. In this arrangement the enclosure stands upon the ground around the pit.

Various embodiments will now be described by way of example and with reference to the accompanying drawings in which: Fig. 1 is a perspective view from the front of a first embodiment of the enclosure in the closed position; Fig. 2 is a like view of the enclosure of Fig. 1 but in the open portion; Fig. 3 is a diagrammatic front view of a second embodiment of the enclosure when in use around a press, Fig. 4 is a front elevation of the enclosure of Fig. 3; Fig. 5 is an elevation of the left hand side of the enclosure of Fig. 3; Fig. 6 is a rear elevation of the acoustic enclosure of Fig. 3; Fig. 7 is an elevation of the right hand side of the enclosure of Fig. 3 showing part of a gantry beam; Fig. 8 is a plan view of the enclosure of Fig. 3; and Fig. 9 is a sectional side elevation showing the internal silencing arrangements for an air intake.

Figures 1 and 2 are diagrammatic and show that a first embodiment of the enclosure 1 comprises an upright portion 2 which is fixed to the floor; a hollow movable portion 3; and means 4, for sealing engagement between the upright portion 2 and the movable portion 3.

In Fig. 1 the movable portion 3 is in the closed position with the sealing means 4 in sealing engagement between the upright portion 2 and the movable portion 3.

In Fig. 2 the movable portion 3 is shown in the open position where it permits access to the enclosure. The sealing means 4 can be seen to be attached to the free edge of the movable portion. Alternatively the sealing means could have been attached to the upright portion.

Two corner posts 5, 6 extend upwardly from the upright portion 2. Each post 5, 6 suports one end of a beam 7, 8 which extends from the plane of the upright portion 2, across the movable portion 3 to a respective corner post 9, 10.

Rollers 11, arranged to roll along each beam 7, 8, are attached to the movable portion 3 by straps such as those denoted 12.

When the movable portion 3 is to be moved, from the closed position to the opened position, the weight of the movable portion is taken by the rolls, (by means not shown) so that the movable portion may then be moved easily to the open position.

The upward movement of the movable portion 3 to clear the ground is desirable and may be achieved in severa! ways such as hydraulic struts in the straps 12 or alternatively an inclined support surface for the rolls 11.

However, the construction may be greatly simplified by suspending the movable portion at a substantially constant height and relying on known wiping seal members attached to the lower edge of the movable portion. Such a wiping seal 13 is indicated in Figs. 1 and 2.

Figures 3 to 9 show in detail the features of a second embodiment of the enclosure, which is particularly suitable for a press used for making tear open can ends.

In Fig. 3 a press 14 is shown in continuous lines and an enclosure 19 is shown by dashed lines. The press 14 stands on an inertia block 15 in a pit 16. The inertia block 15 and press 14 are supported by an anti-vibration member 17 which isolates the inertia block from the ground 18, so that vibrations induced in the block 15, by the press 14, are not passed to the ground 18.

The enclosure 19 stands on the ground around the pit and serves not only to contain the noise from the press but also as a guard to protect people from the moving parts of the press.

The features of the enclosure 19 shown dashed in Fig. 3 can be further understood by reference to Fig. 4 which shows the same view of the front wall enclosure on a enlarged scale.

Reference to Fig. 3 shows how particular features of the press 14 can be related to certain features of the enclosure 19.

The press 14 comprises a rectilinear frame 20 in which the crankshaft and drive motor are overhead (but not shown) and so the aperture 21 in the front wall 22 of the enclosure, through which the power supply cable 23 is passed, is high in the front wall 22.

A clutch/flywheel assembly 24 is attached to the end of the crankshaft and protrudes to the left of the press frame 20. The enclosure 19 is therefore provided with a hollow door member 25 which, when opened, permits access to the clutch flywheel assembly 24 for maintenance and press tool setting. During tool setting the press may, if desired, be turned by hand using a lever inserted into sockets 26 in the flywheel.

The upper press tools 27 are fixed to a ram 28 moved by the crankshaft. The lower press tools 29 are fixed to a bolster 30 supported by the press frame 20. Direct access to the tools 27, 29 is achieved by opening the double doors 31, 32 in the front wall 22 of the enclosure 19. Each of the doors 31, 32 has a window which is double glazed.

Just above the centre line of the double doors is located a rectangular aperture 33 as can best be seen in Fig. 4. This aperture 33 is closed by an acoustic barrier material such as reinforced rubber sheet. The material is cut away to permit a feed conveyer tube 34 to pass through it, but fits around the conveyer tube 34 sufficiently to minimise the noise.

To the right and upward from the aperture 33, is located a further aperture 35 through which passes the exit tube 36 used to remove the can ends from the press. The aperture 35 is also substantially sealed by a reinforced rubber sheet member cut away to seal around the tube 36.

In Fig. 4, the front wall 22 of the enclosure can be seen to have a pair of supports 37, 38 extending upwards from the top af the wall.

These supports 37, 38 provide a first support for respective beams 39, 40 from which a movable portion 41 (Fig. 5) of the enclosure is suspended for movement.

In Fig. 5 the front wall 22 is shown fixed firmly to the ground 18 and to the right of the movable portion 41. The movable portion 41 is suspended from the beam 39 by means of a plurality of rolls 11 connected to a spreader beam 42 of the movable portion. The beam 39 is supported by the support 37 at the front wall 22 and a post 43 which is firmly fixed to the ground 18. A similar post (not shown) in conjunction with upright 38 supports the beam 40.

The movable portion 41 has a rubber sealing strip 44 attached to its free edge which engages with the front wall 22. The free edge and sealing strip 44 are guided to engage with the front wall 22 by means of guide plates 45 which slidably engage with the sides of the front wall 22 as the movable portion 41 is closed thereto, as shown in Fig. 8. Toggle latches 46 are used to put the seal 44 under slight compression to effect the seal between the movable portion 41 and the front wall 22.

These toggle latches need not be very strong because the weight of the movable portion is taken by the beams 39, 40.

The seal 47 between the movable portion 41 and the ground is a sliding seal of a kind having an array of closely packed bristles which serve, not only as a barrier to noise but also sweep the seal contact area clean as the movable portion 41 is moved. The top load on the wiping seals 47 can be adjusted by adjusting the height at which the movable portion 41 is suspended from the beams 39, 40.

Fig. 6 shows the back wall 48 of the movable portion and the front supports 38, 39 extending above it. The flywheel cover 25 can be seen to the right of the drawing. Double doors 49, 50 provide access to the tools in the press. Door 50 has a double glazed window 51. Door 49 has an aperture 52 suitable for feeding in a strip of metal used to make the tabs of the tear open ends made by the press.

Further access doors 63 are provided for access to the upper regions of the press frame.

To be successful as a noise barrier the enclosure has to be as airtight as possible and this can result in an unacceptable build up of heat in the enclosures from the operation of the press e.g. from the drive motor. Therefore ventilation is achieved by means of a fan 53 and exit duct 54 which are shown by dashed lines in Fig. 6. The exit grills 55 from duct 54 are best seen in Fig. 7. The duct 54 is constructed and arranged to attenuate the noise emerging from the enclosure through the duct 54.

The air, moved out of the enclosure by fan 53, is replaced by air which enters the enclosure through grills 58 in the doors denoted 56 in Fig. 5 and 57 in Fig. 7.

Each grill 58 leads to a silencer box incorporated in the doors as shown in Fig. 9 which is a part section of door 57. The silencer box is of the "straight through" type and is defined by the outer plate 59 and the inner plate 60 of the door. Each plate 59, 60 is covered with an acoustic absorbent material 61. The air enters the silencer box through grill 58 and leaves through a lower grill 62 to ventilate the enclosure.

It will be noticed, by reference to Fig. 5, that the flywheel cover door 25 extends for wards beyond the movable portion 41 to over lie the front wall 22, to which it is latched by a toggle latch 63 (see Fig. 4). This arrange ment is necessary because the aperture in the movable portion, which the door 25 covers, is "C" shaped to enable the movable portion to pass the protruding flywheel 24.

The enclosure of Figs. 3 to 9 serves not only to contain the noise emitted by the press but also as a guard to protect people from the moving parts of the press. Therefore each door is preferably provided with electrical contact switches which shut off the power supply to the press immediately a door is opened.

In a preferred embodiment of the enclosure of Figs. 3 to 9 the front wall 22 and movable portion 4-1 are constructed from inner and outer steel plates. The outer plates are plane and painted and the inner plates are perforated. Acoustic absorbent material between the outer and inner plates absorbs noise so preventing a noise build-up within the en closure. With an average barrier weight of about 5 lbs. per square foot the noise outside the enclosure can be reduced to less than 90 dB(A) when a press emitting 100 dB(A) is working inside the enclosure.

It will be understood, by those practised in the art, that the arrangements of the doors and apertures will be chosen with regard to the particular needs of the machine to be enclosed. It is preferable that the enclosure fits closely around the machine so that it is impossible for personnel to be enclosed with the machine while it is running.

Whilst the invention has been described in terms of an enclosure for a large press, about ten feet long by ten feet wide and ten feet tall, the invention can be applied to small machines. When the movable portion is light enough the rear support posts and gantry may be replaced by any convenient means such as a fork lift truck or mobile crane.

WHAT WE CLAIM IS: 1. A noise reducing enclosure, adapted to enclose noise emitting apparatus and contain the noise therefrom, comprising an upright portion having means to fix it to the ground and a hollow movable portion having sealing means to make an acoustic seal with the ground and means for acoustic sealing engagement between the upright portion and the movable portion.

2. An enclosure according to claim 1 wherein the upright portion is substantially planar and vertical and the movable portion has a roof portion and at least one side wall portion.

3. An enclosure according to either preceding claim wherein the fixed portion provides at least a first support for means to move the movable portion away from the fixed portion, to permit access into the enclosure.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. front wall 22 and a post 43 which is firmly fixed to the ground 18. A similar post (not shown) in conjunction with upright 38 supports the beam 40. The movable portion 41 has a rubber sealing strip 44 attached to its free edge which engages with the front wall 22. The free edge and sealing strip 44 are guided to engage with the front wall 22 by means of guide plates 45 which slidably engage with the sides of the front wall 22 as the movable portion 41 is closed thereto, as shown in Fig. 8. Toggle latches 46 are used to put the seal 44 under slight compression to effect the seal between the movable portion 41 and the front wall 22. These toggle latches need not be very strong because the weight of the movable portion is taken by the beams 39, 40. The seal 47 between the movable portion 41 and the ground is a sliding seal of a kind having an array of closely packed bristles which serve, not only as a barrier to noise but also sweep the seal contact area clean as the movable portion 41 is moved. The top load on the wiping seals 47 can be adjusted by adjusting the height at which the movable portion 41 is suspended from the beams 39, 40. Fig. 6 shows the back wall 48 of the movable portion and the front supports 38, 39 extending above it. The flywheel cover 25 can be seen to the right of the drawing. Double doors 49, 50 provide access to the tools in the press. Door 50 has a double glazed window 51. Door 49 has an aperture 52 suitable for feeding in a strip of metal used to make the tabs of the tear open ends made by the press. Further access doors 63 are provided for access to the upper regions of the press frame. To be successful as a noise barrier the enclosure has to be as airtight as possible and this can result in an unacceptable build up of heat in the enclosures from the operation of the press e.g. from the drive motor. Therefore ventilation is achieved by means of a fan 53 and exit duct 54 which are shown by dashed lines in Fig. 6. The exit grills 55 from duct 54 are best seen in Fig. 7. The duct 54 is constructed and arranged to attenuate the noise emerging from the enclosure through the duct 54. The air, moved out of the enclosure by fan 53, is replaced by air which enters the enclosure through grills 58 in the doors denoted 56 in Fig. 5 and 57 in Fig. 7. Each grill 58 leads to a silencer box incorporated in the doors as shown in Fig. 9 which is a part section of door 57. The silencer box is of the "straight through" type and is defined by the outer plate 59 and the inner plate 60 of the door. Each plate 59, 60 is covered with an acoustic absorbent material 61. The air enters the silencer box through grill 58 and leaves through a lower grill 62 to ventilate the enclosure. It will be noticed, by reference to Fig. 5, that the flywheel cover door 25 extends for wards beyond the movable portion 41 to over lie the front wall 22, to which it is latched by a toggle latch 63 (see Fig. 4). This arrange ment is necessary because the aperture in the movable portion, which the door 25 covers, is "C" shaped to enable the movable portion to pass the protruding flywheel 24. The enclosure of Figs. 3 to 9 serves not only to contain the noise emitted by the press but also as a guard to protect people from the moving parts of the press. Therefore each door is preferably provided with electrical contact switches which shut off the power supply to the press immediately a door is opened. In a preferred embodiment of the enclosure of Figs. 3 to 9 the front wall 22 and movable portion 4-1 are constructed from inner and outer steel plates. The outer plates are plane and painted and the inner plates are perforated. Acoustic absorbent material between the outer and inner plates absorbs noise so preventing a noise build-up within the en closure. With an average barrier weight of about 5 lbs. per square foot the noise outside the enclosure can be reduced to less than 90 dB(A) when a press emitting 100 dB(A) is working inside the enclosure. It will be understood, by those practised in the art, that the arrangements of the doors and apertures will be chosen with regard to the particular needs of the machine to be enclosed. It is preferable that the enclosure fits closely around the machine so that it is impossible for personnel to be enclosed with the machine while it is running. Whilst the invention has been described in terms of an enclosure for a large press, about ten feet long by ten feet wide and ten feet tall, the invention can be applied to small machines. When the movable portion is light enough the rear support posts and gantry may be replaced by any convenient means such as a fork lift truck or mobile crane. WHAT WE CLAIM IS:

1. A noise reducing enclosure, adapted to enclose noise emitting apparatus and contain the noise therefrom, comprising an upright portion having means to fix it to the ground and a hollow movable portion having sealing means to make an acoustic seal with the ground and means for acoustic sealing engagement between the upright portion and the movable portion.

4. An enclosure according to claim 3 having

at least a second support means located behind the movable portion, and at least one beam, said beam extending from the second support means across the movable portion to the fixed portion which provides a first support for the beam, said movable portion being suspended from said beam during movement thereof.

5. An enclosure, according to any preceding claim having at least one aperture in the upright portion, through which aperture the needs of any apparatus therein may be supplied.

6. An enclosure according to any preceding claim having at least one opening in the movable portion, to permit access to at least part of any apparatus therein.

7. An enclosure according to any preceding claim when standing upon the ground and enclosing apparatus capable of emitting noise, wherein the upright wall portion is fixed to the ground and the hollow movable portion is sealably engaged to the fixed wall portion and to the ground.

8. An enclosure according to claim 7, having means to raise the movable portion clear of the ground before moving horizontally.

9. An enclosure according to claim 7 or claim 8 when surrounding apparatus isolated from the ground, said enclosure enclosing the apparatus.

10. An enclosure according to claim 9 when enclosing a press mounted upon an isolated block, said block being in a pit below ground level, said enclosure being mounted on the ground around the pit.

11. An enclosure, substantially as hereinbefore described with reefrence to Figs. 1 and 2.

12. An enclosure substantially as hereinbefore described with reference to Figures 3 to 9.