GB2039266A

GB2039266A - Constant rate hopper discharge apparatus

Info

Publication number: GB2039266A
Application number: GB7900814A
Authority: GB
Original assignee: Simon Vicars Ltd
Current assignee: Simon Vicars Ltd
Priority date: 1979-01-09
Filing date: 1979-01-09
Publication date: 1980-08-06
Also published as: JPS55124024A; JPS6125294B2; IT8019048A0; IT1130183B; AR220802A1; GB2039266B; AU5445780A

Abstract

An apparatus for metering powdered substances such as a mixture of fat and flour at a constant rate onto a moving surface, e.g. a dough sheet 42 carried by a conveyor belt 40 comprises a supply hopper (10) for the substance, a pair of parallel substantially horizontal rollers (12) and (14) forming the bottom of the hopper such that a gap (16) between the rollers acts as a metering orifice for the substance, a first scraper (26) for removing the substance from one of the rollers and directing it onto the other of the rollers, and a second scraper (30) for removing the substance from the other of the rollers and directing it onto a rotor (32), the rotor being so disposed as to intercept the material and having blades (34) which cooperate with a stationary blade (28) to effect a shearing action on the material whereby the material is broken up into particulate form of substantially constant size. <IMAGE>

Description

SPECIFICATION Apparatus for metering a powdered substance This invention relates to apparatus for metering a powdered substance, such as a mixture of fat and flour, at a constant rate from a supply hopper and spreading it onto a moving surface.

Apparatus of this general kind is disclosed in British Patent specification No. 1011866 which describes a supply hopper for the substance, a pair of parallel substantially horizontal rollers forming the bottom of the hopper such that the gap betwen the rollers acts as a metering orifice for the substance, a first scraper for removing substance from one of the rollers and directing it onto the other of the rollers, and a second scraper for removing substance from the other of the rollers and directing it onto a rotor, which rotor is arranged to break up and throw the substance against a plate which serves to deflect the substance onto a moving surface.

The arrangement disclosed in the said specification suffers from the disadvantage that large lumps of the substance can fall from the said other roller and pass unbroken onto the moving surface without being caught by the rotor and reduced in size.

An object of the present invention is to provide apparatus for metering a powdered substance, wherein the aforementioned disadvantage is avoided.

Thus according to the present invention there is provided an apparatus for metering a powdered substance such as a mixture of fat and flour at a constant rate onto a moving surface, the apparatus comprising a supply hopper for the substance, a pair of parallel substantially horizontal rollers forming the bottom of the hopper such that a gap between the rollers acts as a metering orifice for the substance, a first scarper for removing substance from one of the rollers and directing it onto the other of the rollers, and a second scaperfor removing substance from the other of the rollers and directing it onto a rotor, the rotor being so disposed with respect to said orifice as to prevent the substance passing through the latter from falling directly onto said moving surface, there being stationary means cooperating with said rotor and forming a gate therebetween through which the substance is directed by the rotor to effect a shearing action on the substance before it passes onto the moving surface.

Preferably one of the rollers is adjustable to and fro relative to the other so that the metering orifice formed by the gap between the rollers can be adjusted.

The invention will be further described by way of example only, with reference to the accompanying drawing which illustrates, diagrammatically an apparatus according to the invention.

The apparatus will be described hereinafter with reference to its application in the baking and confectionery industries wherein a continuous feed of fat and flour mixture known as "cracker dust" is required to be deposited onto a sheet of dough prior to laminating in the production of cream crackers.

However, it will be appreciated that the apparatus can be used with other powdered substances of a similar nature and is not limited to this application.

Referring now to the drawing, the apparatus comprises a supply hopper 10 having four walls and a pair of parallel rollers 12 and 14 forming the bottom of the hopper such that a gap 16 between the roller peripheries acts as a metering orifice for the cracker dust contained in the hopper 10. The roller 12 is adjustable to and fro relative to the roller 14 so as to enable the gap 16 to be adjusted. The longitudinal sides 18 of the hopper have arcuate flanges 20 extending outwardly from the lower edges thereof and the transverse sides 22 are extended downwardly at 24 to provide a seal between the hopper 10 and the rollers 12 and 14.

A first scraper blade 26 extends across the roller 14 and is mounted substantially tangential thereto to contact the periphery thereof lying within the gap 16.

The blade 26 is mounted via a block 27 on a pivoted arm 28. The arm 28 which is pivotable about an axis 29, is spring-loaded to maintain the blade 26 in scraping contact with the surface of roller 14.

A second scraper blade 30 is mounted tangentially to and across the roller 12 but is contained in a plane substantially at 45" to the plane of the scraper blade 26 below the latter. The scaper blade 30 is formed as an arm which is pivotable about an axis 31 and is spring-loaded to maintain scraping contact with the roller 12.

A driven rotor 32 is mounted for rotation in the direction of arrow C and is so disposed relative to the gap 16 as to prevent direct downward passage of cracker dust through the orifice onto the moving surface (indicated generally at 34). The rotor 32 has a number of radial blades 34 the outer edges of which form, together with the arm 28, a gate through which all of the material issuing from the gap 16 must pass.

When the apparatus is in use, therefore, the rollers 12 and 14 are driven in the direction of the arrows A and B, and the cracker dust contained in the hopper 10 feeds through the metering gap 16 at a constant rate consistent with the speed of rotation of the rollers. The cracker dust adheres to the peripheries of the rollers, and the scraper blade 26 removes the cracker dust adhering to the roller 14 and directs it on to the roller 12 which carries itto the scraper blade 30. The cracker dust is then led by the scraper blade 30 into the path of rotating movement of the blades 34 on the rotor 32 which is rotating at a very much higher speed than the rollers 12 and 14. The action of the rotor blades 34 is to break up the cracker dust and to drive it into the gate between the rotor blades and the arm 28. In this way, the cracker dust is subjected to a shearing action and is directed in particulate form onto the moving surface 34.

The moving surface comprises a conveying web 40 having a dough sheet 42 thereon. A pair of baffles 44 and 45 are attached respectively to arm 28 and blade 30 to act as a hood to contain the cracker dust as it descends onto the dough sheet 42.

1. An apparatus for metering a powdered substance such as a mixture of fat and flour at a constant

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Apparatus for metering a powdered substance This invention relates to apparatus for metering a powdered substance, such as a mixture of fat and flour, at a constant rate from a supply hopper and spreading it onto a moving surface. Apparatus of this general kind is disclosed in British Patent specification No. 1011866 which describes a supply hopper for the substance, a pair of parallel substantially horizontal rollers forming the bottom of the hopper such that the gap betwen the rollers acts as a metering orifice for the substance, a first scraper for removing substance from one of the rollers and directing it onto the other of the rollers, and a second scraper for removing substance from the other of the rollers and directing it onto a rotor, which rotor is arranged to break up and throw the substance against a plate which serves to deflect the substance onto a moving surface. The arrangement disclosed in the said specification suffers from the disadvantage that large lumps of the substance can fall from the said other roller and pass unbroken onto the moving surface without being caught by the rotor and reduced in size. An object of the present invention is to provide apparatus for metering a powdered substance, wherein the aforementioned disadvantage is avoided. Thus according to the present invention there is provided an apparatus for metering a powdered substance such as a mixture of fat and flour at a constant rate onto a moving surface, the apparatus comprising a supply hopper for the substance, a pair of parallel substantially horizontal rollers forming the bottom of the hopper such that a gap between the rollers acts as a metering orifice for the substance, a first scarper for removing substance from one of the rollers and directing it onto the other of the rollers, and a second scaperfor removing substance from the other of the rollers and directing it onto a rotor, the rotor being so disposed with respect to said orifice as to prevent the substance passing through the latter from falling directly onto said moving surface, there being stationary means cooperating with said rotor and forming a gate therebetween through which the substance is directed by the rotor to effect a shearing action on the substance before it passes onto the moving surface. Preferably one of the rollers is adjustable to and fro relative to the other so that the metering orifice formed by the gap between the rollers can be adjusted. The invention will be further described by way of example only, with reference to the accompanying drawing which illustrates, diagrammatically an apparatus according to the invention. The apparatus will be described hereinafter with reference to its application in the baking and confectionery industries wherein a continuous feed of fat and flour mixture known as "cracker dust" is required to be deposited onto a sheet of dough prior to laminating in the production of cream crackers. However, it will be appreciated that the apparatus can be used with other powdered substances of a similar nature and is not limited to this application. Referring now to the drawing, the apparatus comprises a supply hopper 10 having four walls and a pair of parallel rollers 12 and 14 forming the bottom of the hopper such that a gap 16 between the roller peripheries acts as a metering orifice for the cracker dust contained in the hopper 10. The roller 12 is adjustable to and fro relative to the roller 14 so as to enable the gap 16 to be adjusted. The longitudinal sides 18 of the hopper have arcuate flanges 20 extending outwardly from the lower edges thereof and the transverse sides 22 are extended downwardly at 24 to provide a seal between the hopper 10 and the rollers 12 and 14. A first scraper blade 26 extends across the roller 14 and is mounted substantially tangential thereto to contact the periphery thereof lying within the gap 16. The blade 26 is mounted via a block 27 on a pivoted arm 28. The arm 28 which is pivotable about an axis 29, is spring-loaded to maintain the blade 26 in scraping contact with the surface of roller 14. A second scraper blade 30 is mounted tangentially to and across the roller 12 but is contained in a plane substantially at 45" to the plane of the scraper blade 26 below the latter. The scaper blade 30 is formed as an arm which is pivotable about an axis 31 and is spring-loaded to maintain scraping contact with the roller 12. A driven rotor 32 is mounted for rotation in the direction of arrow C and is so disposed relative to the gap 16 as to prevent direct downward passage of cracker dust through the orifice onto the moving surface (indicated generally at 34). The rotor 32 has a number of radial blades 34 the outer edges of which form, together with the arm 28, a gate through which all of the material issuing from the gap 16 must pass. When the apparatus is in use, therefore, the rollers 12 and 14 are driven in the direction of the arrows A and B, and the cracker dust contained in the hopper 10 feeds through the metering gap 16 at a constant rate consistent with the speed of rotation of the rollers. The cracker dust adheres to the peripheries of the rollers, and the scraper blade 26 removes the cracker dust adhering to the roller 14 and directs it on to the roller 12 which carries itto the scraper blade 30. The cracker dust is then led by the scraper blade 30 into the path of rotating movement of the blades 34 on the rotor 32 which is rotating at a very much higher speed than the rollers 12 and 14. The action of the rotor blades 34 is to break up the cracker dust and to drive it into the gate between the rotor blades and the arm 28.In this way, the cracker dust is subjected to a shearing action and is directed in particulate form onto the moving surface 34. The moving surface comprises a conveying web 40 having a dough sheet 42 thereon. A pair of baffles 44 and 45 are attached respectively to arm 28 and blade 30 to act as a hood to contain the cracker dust as it descends onto the dough sheet 42. CLAIMS

1. An apparatus for metering a powdered substance such as a mixture of fat and flour at a constant rate onto a moving surface, the apparatus comprising a supply hopper for the substance, a pair of parallel substantially horizontal rollers forming the bottom of the hopper such that a gap between the rollers acts as a metering orifice for the substance, a first scraper for removing the substance from one of the rollers and directing it onto the other of the rollers and a second scraper for removing substance from the other of the rollers and directing it onto a rotor, the rotor being so disposed with respect to said orifice as to prevent the substance passing through the latter from falling directly onto said moving surface, there being stationary means cooperating with said rotor and forming a gate therebetween through which the substance is directed by the rotorto effect a shearing action on the substance before it passes onto the moving surface.

2. An apparatus according to claim 1, in which one of the rollers is adjustable to and fro relative to the other so that the metering orifice can be adjusted.

3. An apparatus according to claim 1 or claim 2, wherein the first scraper blade extends across said one of the rollers and is mounted substantially tangential thereto to contact the periphery thereof lying within the metering orifice.

4. An apparatus according to any one of claims 1 to 3, in which the second scraper blade extends across said other of the rollers and is mounted tengentially thereto and is contained within a plane substantially at 45" to the plane of the first scraper blade.

5. An apparatus according to any one of the preceding claims, wherein said first scraper blade is mounted on a pivoted arm which forms, in operation, said stationary means cooperating with said rotor.

6. An apparatus according to any one of the preceding claims, wherein said scraper blades are pivotally mounted on a pair of axes and are springloaded thus to be maintained in scraping contact with the surfaces of the respective rollers.

7. An apparatus according to any one of the preceding claims, wherein said rotor includes a series of radial blades extending from the surface thereof, the blades cooperating with said stationary means.

8. An apparatus for metering a powdered substance at a constant rate, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.