GB2116864A

GB2116864A - Machine for mixing plaster

Info

Publication number: GB2116864A
Application number: GB08207220A
Authority: GB
Inventors: Steven Jodrell
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-03-11
Filing date: 1982-03-11
Publication date: 1983-10-05
Also published as: GB2116864B

Abstract

The machine includes means (16 and 23) for supplying dry plaster and water respectively at controlled rates to a mixing pan (15) having an aperture (26) therein. Rotatable paddle means (24,25,29) within the pan effect the mixing and include blades (29) to push mixed plaster continuously outwardly through the aperture (26). <IMAGE>

Description

SPECIFICATION Machine for mixing plaster This invention concerns a machine for mixing plaster and is suitable for most of the different kinds of plaster in common use in the building industry.

Conventionally plaster is mixed by hand in batches in a tank which is manually loaded with the dry ingredients and water. This process, besides being messy, is labour intensive, wasteful and generally inconvenient.

It is an object of the present invention to provide a machine which will deliver a continuous supply of mixed plaster at a rate at least sufficient to service the requirements of a plasterer thus eliminating the necessity for a supporting labourer.

According to the present invention there is provided a machine for mixing plaster comprising a mixing pan, means for continuously supplying dry plaster and water to the top of said pan at controlled rates, rotatable paddle means operable within the pan to mix the dry plaster and water, and door at the base of said pan which can be opened when required for the supply of mixed plaster under the action of said paddle means.

The invention will be further apparent from the following description with reference to the single figure of the accompanying drawings, which shows, by way of example only, a cross-sectional view through one form of machine embodying the invention.

Referring now to the drawing it will be seen that the machine comprises a casing of circular crosssection mounted on wheels 10 and equipped with a handle 11 ali for ease of manoeuverability.

The lower part of the casing forms a hopper-like container 12 typically capable of holding the contents of one and a half standard sized bags of plaster which can be introduced through an opening 13 equipped with a fabric sleeve 14 depending into the casing which clings to a bag being emptied, thus reducing dust emission. A screen 14a is provided to prevent foreign bodies, such as paper from the bag being emptied, from falling into the hopper.

The upper part of the casing houses an opentopped mixing pan 15, of circular section when seen in plan.

A tube 16 extends vertically upwards from a position adjacent the base of the container 12 and through the centre of the base of the pan 15 to terminate at a position above the side walls thereof.

A drive motor 17, preferably adapted to be driven from the electrical mains supply is provided at the head of the machine and is coupled with a drive shaft 18 extending vertically through the tube 16by way of a reduction gear box 19.

Connected to the drive shaft 18 and within the tube 16 is a continuous helical flight 20 forming a conveying screw to lift plaster from the base of the container 12 and discharge it into the pan 15 at the top thereof, inlet and outlet apertures, 21 and 22 respectively, being provided in the tube 16 for this purpose. The action of the conveying screw is to supply the pan 15 with dry plaster at a controlled and substantially constant rate.

Water is supplied to the pan 15 with the dry plaster through a pipe 23 which can be supplied from the mains through an adjustable throttle valve 23a so that the supply of water is correct to give mixed plaster of the required consistency.

Also connected to the shaft 18 and operable within the pan 15 are a mixing blades 24 and scraper blades 25 which act on the inner wall of the pan 15 and outerwall ofthetube 16withinthe pan as well as further blades 29 angled to push the mix outwardly as they rotate.

An aperture 26 which can be closed by a vertically slidable door 27 is provided in the wall of the pan 15 at the base thereof. The door 27 is urged against the outer wall of the pan by spring or other resilient means.

The shaft 18 also carried a stirring member 28 at its lower end which together with blades 33 asist the flow of plaster into the aperture 21 by preventing clogging and bridging. The container has a conical baffle 41 over the member 28 to assist the flow of powder and prevent the member 28 from being overloaded.

In use, starting with the pan 15 empty, plaster and water are supplied to the pan 15 for mixing. When the pan is loaded to a certain extent and the mix prepared the door 27 is lifted so that mixed plaster is supplied through the aperture 26 under the action of the blades 29 for flow down a detachable chute 30 to collect in the centre of a plasterer's table from which a plasterer may gather the material. The casing is conveniently provided with a relieved portion so that it can be wheeled over the edge of the table as shown.

An openable door 40 is provided in the tube 16 below the level of the mixing pan 15 to enable dry plaster to be returned from the tube 16 to the container 12 when cleaning the pan 15 with the motor 17 running to operate the blades 24,25 and 29.

It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art being possible without departing from the scope thereof.

CLAIMS (Filed on 21/12/82) 1. A machine for mixing plaster comprising a mixing pan, means for continuously supplying dry plaster and water to said pan at controlled rates, rotatable paddle means operable within the pan to mix the dry plaster and water, and an aperture in the the pan for the continuous supply of mixed plaster under the action of said paddle means.

2. A machine according to claim 1, wherein said aperture is located in a side wall of the pan adjacent the base thereof.

3. A machine according to claim 1, wherein said aperture can be closed by a door.

4. A machine according to claim 3, wherein said door is vertically slidable over the aperture.

5. A machine according to any preceding claim, wherein said pan is located above a hopper for

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Machine for mixing plaster This invention concerns a machine for mixing plaster and is suitable for most of the different kinds of plaster in common use in the building industry. Conventionally plaster is mixed by hand in batches in a tank which is manually loaded with the dry ingredients and water. This process, besides being messy, is labour intensive, wasteful and generally inconvenient. It is an object of the present invention to provide a machine which will deliver a continuous supply of mixed plaster at a rate at least sufficient to service the requirements of a plasterer thus eliminating the necessity for a supporting labourer. According to the present invention there is provided a machine for mixing plaster comprising a mixing pan, means for continuously supplying dry plaster and water to the top of said pan at controlled rates, rotatable paddle means operable within the pan to mix the dry plaster and water, and door at the base of said pan which can be opened when required for the supply of mixed plaster under the action of said paddle means. The invention will be further apparent from the following description with reference to the single figure of the accompanying drawings, which shows, by way of example only, a cross-sectional view through one form of machine embodying the invention. Referring now to the drawing it will be seen that the machine comprises a casing of circular crosssection mounted on wheels 10 and equipped with a handle 11 ali for ease of manoeuverability. The lower part of the casing forms a hopper-like container 12 typically capable of holding the contents of one and a half standard sized bags of plaster which can be introduced through an opening 13 equipped with a fabric sleeve 14 depending into the casing which clings to a bag being emptied, thus reducing dust emission. A screen 14a is provided to prevent foreign bodies, such as paper from the bag being emptied, from falling into the hopper. The upper part of the casing houses an opentopped mixing pan 15, of circular section when seen in plan. A tube 16 extends vertically upwards from a position adjacent the base of the container 12 and through the centre of the base of the pan 15 to terminate at a position above the side walls thereof. A drive motor 17, preferably adapted to be driven from the electrical mains supply is provided at the head of the machine and is coupled with a drive shaft 18 extending vertically through the tube 16by way of a reduction gear box 19. Connected to the drive shaft 18 and within the tube 16 is a continuous helical flight 20 forming a conveying screw to lift plaster from the base of the container 12 and discharge it into the pan 15 at the top thereof, inlet and outlet apertures, 21 and 22 respectively, being provided in the tube 16 for this purpose. The action of the conveying screw is to supply the pan 15 with dry plaster at a controlled and substantially constant rate. Water is supplied to the pan 15 with the dry plaster through a pipe 23 which can be supplied from the mains through an adjustable throttle valve 23a so that the supply of water is correct to give mixed plaster of the required consistency. Also connected to the shaft 18 and operable within the pan 15 are a mixing blades 24 and scraper blades 25 which act on the inner wall of the pan 15 and outerwall ofthetube 16withinthe pan as well as further blades 29 angled to push the mix outwardly as they rotate. An aperture 26 which can be closed by a vertically slidable door 27 is provided in the wall of the pan 15 at the base thereof. The door 27 is urged against the outer wall of the pan by spring or other resilient means. The shaft 18 also carried a stirring member 28 at its lower end which together with blades 33 asist the flow of plaster into the aperture 21 by preventing clogging and bridging. The container has a conical baffle 41 over the member 28 to assist the flow of powder and prevent the member 28 from being overloaded. In use, starting with the pan 15 empty, plaster and water are supplied to the pan 15 for mixing. When the pan is loaded to a certain extent and the mix prepared the door 27 is lifted so that mixed plaster is supplied through the aperture 26 under the action of the blades 29 for flow down a detachable chute 30 to collect in the centre of a plasterer's table from which a plasterer may gather the material. The casing is conveniently provided with a relieved portion so that it can be wheeled over the edge of the table as shown. An openable door 40 is provided in the tube 16 below the level of the mixing pan 15 to enable dry plaster to be returned from the tube 16 to the container 12 when cleaning the pan 15 with the motor 17 running to operate the blades 24,25 and 29. It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art being possible without departing from the scope thereof. CLAIMS (Filed on 21/12/82)

1. A machine for mixing plaster comprising a mixing pan, means for continuously supplying dry plaster and water to said pan at controlled rates, rotatable paddle means operable within the pan to mix the dry plaster and water, and an aperture in the the pan for the continuous supply of mixed plaster under the action of said paddle means.

5. A machine according to any preceding claim, wherein said pan is located above a hopper for containing dry plaster to be supplied to the pan.

6. A machine according to claim 5, including conveying means for transfering dry plaster from said hopper to the interior of said pan.

7. A machine according to claim 6, wherein said conveying means comprises a screw rotatable in a vertical tube which rises through the hopper and the pan.

8. A machine according to any preceding claim, wherein said pan is of circular cross-section and wherein said rotatable paddle means includes mixing blades and scraper blades which engage with the inner wall of the pan.

9. A machine according to any preceding claim, wherein said rotatable paddle means includes blades angled to push the mix towards said aperture.

10. A machine according to either claim 6 or 7, including stirring means in the base of said hopper to aid flow of the dry plaster into said conveying means.

11. A machine according to any preceding claim, wherein all the moving parts are connected to a common drive shaft driven by a motor via a reduction gear box.

12. A machine according to any preceding claim, which is mounted on wheels and provided with a handle for ease of manoeuverability.

13. A machine according to any preceding claim, having a relieved portion in its cross-section to enable it to be positioned against a plasterer's table so that mix extruded by the machine is deposited on to the top of such table.

14. A machine for mixing plaster substantially as described herein with reference to and as illustrated by a single figure of the accompanying drawing.