GB2436440A

GB2436440A - Tumbling device

Info

Publication number: GB2436440A
Application number: GB0626003A
Authority: GB
Inventors: Thomas Bartlett Snell
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-12-29
Filing date: 2006-12-29
Publication date: 2007-09-26
Also published as: GB0626003D0; GB0526558D0

Abstract

A tumbling device comprises a drum B arranged for rotation relative to a support structure A and C. The drum B has an inlet end into which objects to be tumbled are loaded and an outlet end from which the tumbled objects are discharged. An adjustable barrier E is provided at the outlet end of the drum B to restrict the discharge of tumbled objects therefrom. Figure 1 shows a barrier E which is pivotable about a point H by means of a hydraulic ram F. Alternatively other types of powered actuator or manual power may be used to adjust the barrier E. The axis of rotation of the drum B relative to the horizontal is adjustable, for example by means of altering the extension of legs J and K which support the outlet end of the drum B. A change in the inclination of the legs relative to the vertical occurs when the angle of tilt of the drum is adjusted. This is compensated for by swiveling feet X and Y or elastic blocks Q mounted on the ends of the legs J and, K and M and N respectively.

Description

TUMBLING DEVICES

Field of The Invention

This invention relates to tumbling devices.

Natural stone used for building houses, walls and the like needs to in a suitable form and size for the stonemason to produce not only a sound structure but also an aesthetically pleasing visual effect for the house or waU as a whole.

Stone used for building or walling is often cut or split to size prior to laying. This results in sharp corners and edges that often benefit from an additional treatment process whereby the sharp corners and edges are distressed or rounded off. The degree of distressing depends on the application, personal taste and, in the case of conservation projects, replication of traditional hand-dressed stone.

Split or cut synthetic stone and concrete products also benefit from distressing the corners and edges thereof.

It is known that a quantity of stone or blocks can be rotated together inside a drum lying approximately horizontally. As the drum rotates, the stones fall over onto and against each other knocking off the corners and sharp edges. This process is known as tumbling.

One of the problems with tumbling devices is that it is difficult to produce a relatively consistent stone product from a continuous mechanised process that can be pre-adjusted or adjusted whilst running.

An object of the present invention is to provide the control and adjustment to produce the desired end product for a given stone type, hardness and size whilst running.

A further object of the present invention is the provision of an improved tumbling device.

A further object of the present invention is the provision of an improved method of tumbling.

Summary of the Invention

According to a first aspect of the present invention there is provided a tumbling device that includes a drum arranged for rotation relative to a support structure, the drum having an inlet end into which objects to be tumbled are loaded and a discharge end from which the tumbled objects are disôharged, an adjustable barner at the discharge end of the drum for restricting the discharge of tumbted objects from the drum.

Means may be provided for adjusting the position of the barrier during rotation of the drum.

Means are preferably provided for varying the inclination of the axis of rotation of the drum relative to the horizontal.

The support structure may comprise a housing within which the drum is mounted and the housing may be mounted on legs. The means for varying the inclination of the axis of rotation of the drum to the horizontal may include means for adjusting the length of at least one of the legs.

The means for varying the inclination of the axis of rotation of the drum preferably comprises means for adjusting the height of the discharge end of the drum. This means that the height of the inlet end of the drum can be kept substantially constant, so as to facilitate conveying of the objects into the drum inlet.

A guard plate is preferably provided at the inlet end of the drum.

According to a second aspect of the present-invention there is provided a method of tumbling stones, concrete products or other objects that includes the use of a tumbling device as defined above.

Brief Description of the Drawinq

Figure 1 is a perspective view of a tumbling device in accordance with the present invention, and Figure 2 shows the entry end of the tumbling device.

Description of the PreferredEmbodiment

The tumbling device shown in the drawings includes a horizontal drum B that is rotated inside a housing afforded by top and bottom case structures A and C on internally mounted driven and idler wheels (not shown). The wheels may be covered with rubber or polyurethane tyres engaging with the drum B. The driven wheels may be rotated by hydraulic power or other power means with or without gearboxes. The drum B will normally run the full length of the housing. The drum B may be lined with a resiSient substance such as rubber or polyurethane and may be perforated to allow dust and small debris to fall through the drum B through mesh underneath the housing to the ground or into a bin or bins.

The main body of the tumbling device, comprising upper and lower case structures A and C respectively with the drum and drive unit inside, may be varied in angle around the horizontal attitude to adjust the progress of the stone entering on the right to its left end of the drum B. The angle of the drum B can be adjusted by extending legs J and K by extendable jacks S that have swivelling feet X and V. Legs J and K are secured to the lower outer case structure C, as are legs M and N at the opposite end of the device.

When the tilt angle of the drum B is changed, the inclination of the front and rear leg sets to the vertical is also changed. In order to compensate for this, elastic blocks 0 are mounted on the low!r ends of the rear legs M and N to take up the small movement. As shown, the elastic blocks 0 are filled with feet.

* As the tilt angle of the drum B is varied by adjusting the height of the discharge end of the drum B, the height of the inlet end of the drum B can be kept substantially constant. This facilitates feeding of the stones or other objects into the drum using a conveyor or other mechanised system.

The exit end of the tumbling device (the left hand end as viewed in Figure 1) is fitted with a rotating barrier E that holds back the stone within the drum B, thereby allowing a larger volume of stone to be tumbled at any moment of time. By altering the angle of the drum B and raising or lowering the barrier E and controlling the speed of rotation of the drum B and the rate that stone is introduced at the input end of the drum B, control is effected over the finished product.

The barrier E can be made to rise and fall by hand power, and it may rise and fall within guides. As illustrated, it can be rotated about a swivel point H powered by a hydraulic ram F that is attached through a swivel 1 on the barrier E and a swivel G on the lower case structure C. The barrier E can be moved to any position within the arc described by the swivel point H. Thus, it may provide a high barrier, a partial barrier or no barrier at all when in its lowest position or any point in between.

It will be appreciated that the barrier E can be powered by any type of manual or powered actuator.

The drum B normally rotates clockwise when viewed from the stone exit end, and the barrier E is shaped accordingly to hold back the stone climbing up the drum between the 30 and 45 minute sector of the clock face.

When the balance of the stone load, the rotation speed, the angle of drum tilt, and the barrier height is correctly adjusted, the rate of stone entering the drum B should approximately equal the rate of the stone spewing over the barrier E and leaving the tumbling device thereby being part of a continuous process.

At the inlet end of the drum B, the diameter can be reduced as indicated at A2 in Figure 2, to provide a higher wall for the stone during processing, but the minimum size of the inlet hole is then compromised by the restricted access to the drum B thus making hand or conveyor loading more difficult.

As a general rule, the softer the stone the lower the barrier E, and the harder the stone the higher the barrier E depending on the desired result. Drum rotation speed and drum angle tilt are additional variables The embodiment shown in the drawings includes a drum B rotating in a housing. However, the drum may not be encased, the drum may not have legs -instead it may be supported by a frame that enables the drum to be tilted at different angles, the drum rotation may be reversed at any time or run forwards or backwards at any time.

All or any part of the cycle of operations of the tumbling device may be controlled by programmes that are preset or by an automatic control that identifies the type of stone, its average size and shape and the required end product' or any combination of pre-programming and automatic control.

It will also be appreciated that the dnirn B can be of varied internal diameter; it may have internal paddles or bars, and the input end of the drum B may have a reduced diameter hole to allow a higher level of stone or concrete blocks to be processed at any one time.

The tumbling device may operate as part of a continuous process, but it is also possible to provide batch production conditions whereby the material is not allowed to escape until a predetermined point in time is reached and then discharged out of the outlet by tilting and/or lowering the barrier E. In the particular embodiment described above and illustrated in the accompanying drawings, the inclination of the axis of rotation of the drum B relative to the horizontal is adjustable during rotation of the drum B. In an alternative embodiment (not shown) the axis of rotation of the drum B is at a fixed inclination to the horizontal and the rate of discharge of the tumbled stones or other objects (and thus the length of time for which tumbling of each stone or other object is effected) is adjusted by adjusting the position of the barrier E during rotation of the drum B. The barrier or sluice B controlling the output of material described above may be covered on the drum side or on both sides with an elastic material to reduce noise and abrasive wear.

At the discharge end of the machine, guards (not shown) may be fitted to prevent the entry of persons into the area of material discharge, the rotating drum and barrier. Removal may be by conveyor or mechanical handling.

At the stone entry end, there is potential hazard of trapping fingers between the rotating drum B and the end lace 02 of the housing. The drum B will rise, fall and move slightly sideways in relation to the end face 02 of the housing depending on the wear of the elastic tyres or other coverings on the driven wheel(s) and the loading of the stone. A guard plate C2 with an aperture marginally larger than the diameter of the drum B is positioned against the outside end face G2 of the housing with a small clearance and incorporates riding wheels E2 and F2 that engage with the outside periphery of the drum B. The riding wheels E2 and F2 are positioned on the inside face of the plate C2 and are set into the housing end lace 02 with a good clearance to allow for movement.

As the drum B rises and falls, the gap between the drum B and plate C2 is constant and minimal thereby not allowing finger entry. The guard plate C2 is fixed to the end face 02 of the housing by fixings H2, 12, J2 and K2 in such manner that the guard plate C2 is free to move a limited amount in relation to the end face 02 of the housing.

Claims

Claims:- 1. A tumbling device that includes a drum arranged for

rotation relative to a support structure, the drum having an inlet end into which objects to be tumbled are loaded and a discharge end from which the tumbled objects are discharged, an adjustable barrier at the discharge end of the drum for restricting the discharge of tumbled objects from the drum.

2. A tumbling device as claimed in Claim 1, which includes means for adjusting the position of the barrier during rotation of the drum.

3. A tumbling device as claimed in either of the preceding claims, which includes means for varying the inclination of the axis of rotation of the drum relative to the horizontal.

4. A tumbling device as claimed in Claim 3, in which the means for varying the inclination of the axis of rotation of the drum comprises means for adjusting the height of the discharge end of the drum.

5. A tumbling device as claimed in any one of the preceding claims, in which the support structure comprises a housing within which the drum is mounted.

6. A tumbling device as claimed in Claim 5, in which the housing is mounted on legs and in which the means for varying the inclination of the axis of rotation of the drum to the horizontal includes means for adjusting the length of at least one of the legs.

7. A tumbling device as claimed in any one of the preceding claims, in which a guard plate is provided at the inlet end of the drum.

8. A tumbling device constructed and arranged to operate substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

9. A method of tumbling stones, concrete products or other objects that includes the use of a tumbling device as claimed in any one of Claims I to 7.

10. A method of tumbling stones, concrete products or other objects substantially as hereinbefore described.