GB2241045A

GB2241045A - Vibration damping in machine mount

Info

Publication number: GB2241045A
Application number: GB9102367A
Authority: GB
Inventors: Robert Edward Hardy Harrison
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-02-10
Filing date: 1991-02-04
Publication date: 1991-08-21
Anticipated expiration: 2011-02-04
Also published as: GB9003061D0; GB9102367D0; GB2241045B

Abstract

A tyre 7 or like tubular means is disposed between a source of vibration 1 and a stressed supporting structure 11 so as to shield the supporting structure from the source of vibration. A machine incorporating this unit is used to dislodge material adhering to the walls of the holds of vessels. <IMAGE>

Description

MACHINE The present invention relates to a device for reducing vibration and to a machine incorporating such a device and to the use of such a machine in dislodging materials adhering to upwardly extending surfaces Concrete breakers, pneumatic drills and like machines create violent recoil and high frequency vibrations. This makes them unsuitable for use in conjunction with supporting machinery of the kind which is highly stressed for instance because of lever type forces acting on it.

Similarly if a source of high energy vibration is held fixed against a rigid immoveable surface without recoil vibration energy being able to escape, the source of vibration will self destruct.

The present invention provides a simple inexpensive dampening device which when positioned between a source of vibration and a fragile or highly stressed supporting structure for the said source of vibration, shields the structure from damaging vibrations and allows the vibrator to be flexibly held against an immoveable object such as the steel side of a ship.

Accordingly the present invention is.for a dampening device comprising an inflatable pneumatic.resilient tube continuous or otherwise and/or tyre, a source of vibration and a supporting structure for the source of vibration. said source of vibration and said supporting structure being connected to said tube or tyre in such a way that said tube or tyre dampens the transmission of vibrations from said source of vibration to said supporting structure.

Preferably the source of vibration is connected to a member in contact with one sidewall of the tube or tyre and the supporting structure is in contact with the other sidewall of the tube or tyre.

In one embodiment of the present invention there is provided a dampening device which comprises an inflatable pneumatic resilient tube continuous or otherwise and/or tyre, a hub for said tube and/or tyre, means connected to the hub and a clamp adapted to grip the tube and/or tyre, said means and said clamp being capable of being connected to one or other of a source of vibration or a supporting structure for the source of vibration.

The source of vibration may for instance be a pneumatic drill or similar machine involving percussive and/or reciprocated motion in which oscillations are induced in the fabric of the machine and in any structure attached thereto.

The means is normally some form of construction adapted to be connected to, optionally demountably connected to, and support the source of vibration The present invention is also for a machine which comprises a dampening device as described above wherein the means is connected to a source of vibration and the tube and/or tyre is gripped by the clamp which in turn is carried by an extendible arm. The extendible arm may be connected to a mobile power source such as a tractor.

In one embodiment of the invention, the supporting structure is an extendible arm which may also be adapted to be movable about an axis. The source of vibration is attached to the extremity of the arm through an intermediate dampening device of the kind according to the present invention.

The source of vibration may be a concrete breaker. Concrete breakers usually have chisel type ends. If instead of a chiseltype end there is substituted a blunt or hammer type head, such a device may be used to impart vibrations to a vertical or upstanding surface thereby to dislodge any material loosely adhering thereto.

In a further embodiment of the invention therefore, there is provided a process for removing material adhering to upwardly extending surfaces which comprises imparting vibrations to the surface desirably using the combination described above. For example material such as damp coal when transported in the hold of a ship, tends to be compressed between the stringers in the side of the hold and hence forms a mass which is difficult to dislodge. In the past this mass has been removed manually by prodding with a rod, or a pole or digging with a spade, an expensive and time-consuming affair. In contrast the process envisaged by the process of the present invention results in the rapid descent of all the adhering coal in a short space of time using only one machine.

The present invention is illustrated in the accompanying drawings in which : Figure 1 is a side sectional elevation of a dampening device and associated source of vibration, Figure 2 is a view from line AA of figure 1 viewed in the direction of the arrows Figure 3 is a side sectional elevation of another embodiment of a dampening device.

Figure 4 is a side elevation of a tractor unit incorporating a device and machine according to the invention.

Figure 5 is a side sectional elevation of a further dampening device according to the invention.

Referring to figures 1 and 2 of the drawings there is illustrated in outline a source of vibration 1 carrying a flat ended striking rod 2 held by bushing 13. The source of vibration 1 is a conventional unit as used in a concrete breaker and striking rod 2 is the chisel portion with the pointed part cut off.

The source of vibration 1 is attached by pins 3 to a mounting member 4 which itself is welded at 5 to the centre part of the hub 6 of a wheel centre assembley. Power lines, not shown, connect the source of vibration with a source of power eg electrical, hydraulic or pneumatic.

The other part of the wheel assembly is a tyre 7 mounted on the hub 6. It is desirable that the tyre be inflated through a valve 14. The extent of inflation will depend on the application to which the system is being put but 7 psi has been found a suitable pressure when dealing with a concrete breaker. Inflation not only serves to control the damping effect on induced vibrations but also serves to secure the tyre to the hub.

A clamping arrangement consists of eight bent members 8 with threaded ends 9. The members 8 carry contoured steel clamps 10 on their inner periphery. The members 8 are screw fitted to a back plate 11. Back plate 11 carries contoured members 12.

The contoured members 10 and 12 are so positioned that as the clamping arrangement is tightened, they grip upon the side walls of the tyre 7.

The clamping arrangement is tightened by adjusting the lengths of members 8 by means of nuts carried on their threaded ends 9.

In use, the vibrations of the source of vibration 1 are absorbed by tyre 7 and are not transmitted to the clamping arrangement.

Therefore any machine connected to the clamping arrangement via back plate 11 is protected from vibrations.

The back plate 11 is attached to a support system. Such a support system is illustrated in figure 4 which shows a tractor 40 provided with a hydraulically extendible arm or boom 43. A system of this sort where the arm may variously extend from 10 to 40 feet is very susceptible to vibration. It is this situation that the dampening effect of the device of the present invention is very effective.

Referring to figure 3, there is illustrated a tyre 27 fitted to a hub 26. Tyre 27 is held by clamps 20 which bear against and grip the tread of tyre 27. There are 1 to 8 in number of these clamps.

If there are more than one of these clamps, these are spaced evenly around the circumference of the tyre. The total perimetric length of the clamps is 20% to 100% the perimeter of the tyre.

Clamps 20 consist of a fixed piece 21 secured to back plate 22 and a moveable piece 23. Each of the pieces carries one or more integral bushings 24 through which can be passed a bolt 25 provided with a head 28 at one end and a nut and thread 29 at the opposite end. The clamps 20 are engaged securely with tyre 27 by passing bolts 25 through bushings 24 and adjusting head and nut 28 and 29 so as to bear on bushings 24 and force the pieces 21 and 23 together thereby to grip tyre 27.

Each of the pieces 21 and 23 are so angled at 30 as to complement the shape of the corner of the tyre 27.

In other respects the machine functions in the same way as that illustrated in figures 1 and 2. Thus back plate 22 is connected to a supporting structure which may be for instance be a relatively long beam which naturally generates large forces at its junction with with its support.

Referring to figure 4, there is illustrated a tractor 40 mounted on which is a bracket 41 which can be swivelled in a horizontal plane. The bracket 41 is provided with a pivot 42 which supports an extendible boom 43. Connected to the free end of boom 43 is a device according to the invention 44 which itself is attached to a unit 45 consisting of the functional part of a hydraulic vibrator. The unit 45 takes its hydraulic and pneumatic power from the tractor 40 through supply conduits not shown.

In operation when removing material from the walls of the hold of a ship, the tractor is driven to face the wall of the hold and the boom is positioned to place the vibrator rod in contact with the coal covered wall. Operation of the rod effects a drumming action on the wall causing the wall to vibrate in unison and it is under this influence that any material such as coal adhering to the wall slumps to the hold floor.

Referring to figure 5, there is illustrated an arrangement which, as in figure 1, shows a mounting member 104 which is connected to a source of vibration and a back plate 111 and this is attached to a support system as illustrated in figure 4. This time the support system is protected from vibrations by a tyre 107 which is of significantly smaller diameter than that illustrated in figure I thereby leading to a more compact form of equipment.

The apparatus illustrated in figure 5 shows a mounting member 104 welded to a front plate 120 which in turn is welded to a dish shaped member 121 which encompasses and closely complements one sidewall and the tread of tyre 107.

The back plate 111 is provided with a series of pedestals 122 with contoured heads 127 arranged to fit the tyre wall in a circular configuration and which are pressed on to that sidewall of tyre 107 not encompassed by dish 121.

A bolt 123 projects through bushings 124 and 125 in plates 111 and 120 respectively. A spring 128 is provided between bolt head 129 and plate 111 and another spring 130 is provided between lock nut 131 on threaded end of bolt 123 and plate 120.

Tightening of the locknut 131 compresses springs 130 and 128 thus pressing together plates 111 and 120 thereby forcing dish 121 and pedestals 122 to grip tyre 107.

The small diameter of tyre 107 means that the unit is more subject to turning moments which may be imposed on it. In order to compensate for this there is provided means to prevent the skew displacement of plates 111 and 120. The means comprises 4 dampers 150 mounted peripherally between plates 111 and 120 and connected thereto. The dampers consist of pistons 151 mounted on rods 152 and adapted to run in cylinders 154. The piston 151 is spring loaded to maintain its position in cylinder 154 by means of opposing springs 155 and 156. Instead of springs, piston 151 may be gas loaded. Movement of the piston and in consequence of plates 111 and 120 is resisted but not prevented and any displacement of the piston from its equilibrium position generates a force promoting the return of the piston to the position where the forces of springs 155 and 156 are balanced.

This effect is reproduced in the location of plates 111 and 120.

In this version of the invention the tyre acts as an absorber of vibrations.

With or without dish 121 there may be used variable length of bushing 126 on bolt 123 which extends between hub 161 and plate 120 thereby transmitting vibrations from mounting member 104 to hub 161.

In this version of the invention the flexing of the tyre on the hub dampens the vibrations.

Differing lengths of bushing 126 provide an additional means of adjustment to control the vibration damping effect as well as tyre 107 pressure and the pre-load tension in bolt 123.

Claims

1. A dampening device comprising an inflatable pneumatic resilient tube continuous or otherwise and/or tyre, a source of vibration and a supporting structure for the source of vibration.

said source of vibration and said supporting structure being connected to said tube or tyre in such a way that said tube or tyre dampens the transmission of vibrations from said source of vibration to said supporting structure.

2. A dampening device as claimed in claim 1 wherein the source of vibration is connected to a member in contact with one sidewall of the tube or tyre or its hub and the supporting structure is in contact with the other sidewall of the tube or tyre.

3. A dampening device comprising an inflatable pneumatic resilient tube continuous or otherwise and/or tyre, a hub on which said tube and/or tyre is mounted, means connected to the hub and a clamp adapted to grip the tube and/or tyre, said means and said clamp being capable of being connected to one or other of a source of vibration or a supporting structure for the source of vibration.

4. A device as claimed in claim 3 wherein said means is welded to the hub.

5. A device as claimed in claim 3 or claim 4 wherein said means is attached to a source of vibration

6. A machine comprising a dampening device as claimed in any of claims 3 to 5, a source of vibration and a boom wherein the means of the dampening device is connected to the source of vibration and the tube and/or tyre is gripped by the clamp which in turn is connected to the boom

7. A machine as claimed in claim 6 wherein the boom is extendible.

8. A machine as claimed in claim 6 or claim 7 wherein the extendible boom is connected to a mobile power source such as a tractor.

9. A machine as claimed in claim 7 or claim 8 wherein the supporting structure is a boom adapted to be movable about an axis.

10. A machine as claimed in any of the previous claims wherein the source of vibration is a concrete breaker.

11. A machine as claimed in claim 10 wherein the concrete breaker has a chisel type end.

12. A machine as claimed in claim 10 wherein the concrete breaker has a blunt or hammer type head.

13. A process for removing material adhering to upwardly extending surfaces which comprises imparting vibrations to the surface.

14. A process for removing material adhering to upwardly extending surfaces which comprises imparting vibrations to the surface using the device as claimed in claims 1 to 5.

15. A process for removing material adhering to upwardly extending surfaces which comprises imparting vibrations to the surface using the machine as claimed in claims 6 to 12.

16. A machine substantially as illustrated in figure of the accompanying drawings.

16. A process for removing material adhering to upwardly extending surfaces as claimed in claims 13 to 15 wherein the material is damp coal, urea, chemical salts or ores.

17. A process for demolition of mortar bonded structures such as buildings which comprises imparting vibrations to the structure using the device as claimed in claims 1 to 5.

18. A dampening device substantially as illustrated in the accompanying drawings.

19. A machine substantially as illustrated in figure 5 of the accompanying drawings.

Amendments to the claims have been filed as follows 1. A dampening device comprising an inflatable pneumatic resilient tube continuous or otherwise and/or tyre, a source of vibration and a supporting structure in the form of a boom for the source of vibration. said source of vibration and said boom being connected to said tube or tyre in such a way that said tube or tyre dampens the transmission of vibrations from said source of vibration to said boom.

2. A dampening device as claimed in claim 1 wherein the source of vibration is connected to a member in contact with one sidewall of the tube or tyre or its hub and the boom is in contact with the other sidewall of the tube or tyre.

3. A dampening device comprising an inflatable pneumatic resilient tube continuous or otherwise and/or tyre, a hub on which said tube and/or tyre is mounted, means connected to the hub and a clamp adapted to grip the tube and/or tyre, said means and said clamp being capable of being connected to one or other of a source of vibration or a supporting structure in the form of a boom for the source of vibration.

4. A device as claimed in claim 3 wherein said means is welded to the hub.

5. A device as claimed in claim 3 or claim 4 wherein said means is attached to a source of vibration 6. A machine as claimed in any of the preceding claims wherein the boom is extendible.

7. A machine as claimed in claim 6 wherein the extendible boom is connected to a mobile power source such as a tractor.

8. A machine as claimed in any of the preceding claims wherein the boom adapted to be movable about an axis.

9. A machine as claimed in any of the previous claims wherein the source of vibration is a concrete breaker.

10. A machine as claimed in claim 9 wherein the concrete breaker has a chisel type end.

11. A machine as claimed in claim 9 wherein the concrete breaker has a blunt or hammer type head.

12. A process for removing material adhering to upwardly extending surfaces which comprises imparting vibrations to the surface using the device as claimed in claims 1 to 11.

13. A process for removing material adhering to upwardly extending surfaces as claimed in claim 12 wherein the material is damp coal, urea, chemical salts or ores.

14. A process for demolition of mortar bonded structures such as buildings which comprises imparting vibrations to the structure using the device as claimed in claims 1 to 11.

15. A dampening device substantially as illustrated in the accompanying drawings.