A METHOD AND APPARATUS FOR APPLYING A LAYER OF A VISCOUS MATERIAL TO A SLICE OF BREAD

Abstract: A viscous foodstuff or bread spread (20) such as butter, margarine, or fat is applied to slices of bread (10) by placing each slice of bread in contact with a wire mesh (12) or a perforated plate. The viscous material (20), which is arranged in a receptacle (19), is then pressed out through the openings defined by the wire mesh and into contact with a desired area of the bread by suitable pressing-out means, which may, for example, be a reciprocatable plunger of scraper (15). The area of the slice of bread to which the viscous material (20) is to be applied is defined by the dimensions of a diaphragm opening (25) which is formed in a diaphragm frame (13). The slice of bread (10) may be removed from the wire mesh (12) by means of a spring activated releasing frame (23) when a layer of the viscous material has been applied to the bread.

Description: A METHOD AND APPARATUS FOR APPLYING A LAYER OF A VISCOUS MATERIAL TO A SLICE OF BREAD The present invention relates to a method of applying a layer of a viscous material, such as butter, margarine, or fat, to a slice of bread. 0 In the more or less industrialized preparation of sandwiches and open sandwiches butter, margarine, or fat is normally applied to slices of bread by means of suitable dispensing apparatus by means of which a rather small number of relatively large lumps of the material in question are deposited on each slice of bread. Thereafter these lumps 15 are pressed or smeared out to some extent when slices of cheese, meat, sausages, etc. are subsequently placed on the slice of bread. When this known method of applying butter or a similar viscous material to slices of bread is used, the layer applied will be rather thick at least a some locations. This means that the viscous material 0 is applied either rather non-uniformly, or that a relatively large total amount of the viscous material is applied, the latter being disadvantageous for reasons of health. It is also known to apply butter and margarine to slices of bread by means of application rollers. By means of this known method it is possible to apply a 25 layer of a substantially uniform desired thickness. On the other hand it is not possible to avoid that part of the butter or viscous material is applied to the edge portions of the slices of bread. This is especially disadvantageous when the bread is used for making closed sandwiches consisting of two superposed slices of bread with 30 cheese or meat arranged there between, because such closed sandwiches are normally held by the fingers when they are consumed. Therefore, the butter, fat, or margarine applied to the edge portions of the slices of bread may give rise to greasy fingers. -.. German Auslegeschhrift No. 1,063,775 also discloses an apparatus for applying butter, margarine, or other viscous materials to slices of bread. This known apparatus comprises a distributor drum having a cylindrical wall with a multiplicity of openings or perforations, and a toothed roller arranged within the drum and having teeth engaging with the openings or perforations of the drum. When the drum and the toothed roller are rotating, a viscous material, which has been pressed into the openings of the drum, is pressed out through these openings in the cylindrical wall of the drum, when the teeth of the roller engage with such openings. Thus, the viscous material is di¬ vided into small portions which fall down onto the upper side of slices of bread, which are moved beneath the distributing drum by means of a conveyer belt. When the slices of bread have passed the drum and small portions of the viscous material have been distributed on the upper side thereof, the slices of bread pass a stationary smearing plate for smearing out the viscous material so that it will form a substantially continuous layer on each slice of bread. Due to this necessary smearing operation this known apparatus is not able to apply the viscous material so that application of the greasy material to the edges of the bread slices is avoided, either. The present invention provides a method which renders it possible to apply a uniform, relatively thin layer of margarine, butter, fat, ' or another viscous material to a desired area of a slice of bread spaced from the edge portions of such slice of bread. The method according to the invention is of the above type, wherein a layer of a viscous material is applied to a slice of bread by press¬ ing the material through a multiplicity of small, closely spaced openings defined in a perforated plate or wall, and the method ac¬ cording to the invention is characterized in that a surface part of said slice of bread is placed in substantially abutting engagement with an abutment surface defined by the outer surface of said perfo¬ rated plate or wall while the viscous material is pressed out through said openings, and in that the said slice of bread is thereafter removed from the abutment surface by a relative movement of said slice of bread and said abutment surface in a direction transversely to the abutment surface. Because the said slice of bread is in abutting engagement with the abutment surface defined by the perforated plate or wall when the viscous material is pressed out through the openings therein, and because the slice of bread to which a layer of the viscous material has been applied is removed from the abutment surface by moving the slice of bread in relation to the abutment surface in a direction transversely to said surface, smearing out of the layer of material applied is avoided. This means that the viscous material may be ap¬ plied to the slice of bread in a desired area having a shape and size corresponding to the shape and size of the perforated area of the said perforated plate or wall. The relative movement between the slice of bread and the abutment surface may be performed by moving the slice of bread and/or by moving the perforated plate or wall. The relative movement is preferably substantially at right angles to the abutment surface even though, in principle, the direction of movement may form an acute angle with such direction extending at right angles to the abutment surface. The perforated plate or wall defining the abutment surface may, for example, be made from coarse cloth or fabric, plate metal with holes stamped therein, or any other perforated plate. In the preferred em¬ bodiment of the method according to the invention, however, the per¬ forated plate or wall is made from a substantially plane, stretched wire mesh. The pressing out of the viscous material through the openings of the perforated plate or wall may be obtained by any suitable manner, for example by mechanical, pneumatic, or hydraulic means. Thus, for ex¬ ample, the pressing out may be obtained by subjecting the viscous material to superatmospheric pressure by means of a piston, or by means of a pneumatic or hydraulic pressure medium. In the preferred embodiment of the method according to the invention, however, the viscous material is pressed out through the openings of the perfo¬ rated plate or wall by means of a scraping member, which is moved along the inner side of said plate or wall in abutting engagement therewith. The thickness of the layer of material which is applied to a slice of bread will be dependent on the pressing-out pressure, the size of the openings, and the type of the plate or wall defining the abutment surface in which the openings are defined. When the viscous material is pressed out by means of a scraping member, the pressing-out pres¬ sure and, consequently, the thickness of the layer of material ap¬ plied will be dependent i.a. on the shape, the arrangement, and the rate of movement of the scraping member. The said scraping member may be moved between a first position in which the openings in said plate or wall are uncovered by the scrap¬ ing member while the inner side of the plate or wall is covered by said viscous material, and a second position in which the inner side of the plate or wall is covered by the scraping member, and the said slice of bread may then be placed in abutting engagement with said abutment surface while said scraping member is in its said first position, and may be removed therefrom, when the scraping member has passed its said first position and has returned to its second posi¬ tion. When the scraping member is ' moved from its second to its first position the slice of bread is pressed into engagement with the abutment surface. This means that a vacuum is created at the inner side of the plate or wall causing the viscous material to be sucked immediately into contact with the inner surface of the plate or wall when uncovered during movement of the scraping member. When the scraping member is subsequently moved from its said first to its said second position while the slice of bread is still maintained in con¬ tact with the abutment surface, the viscous material is pressed out¬ wards through the openings and into contact with the slice of bread. When the slice of bread is removed from the abutment surface a layer of the viscous material in the form of a very large number of small, closely spaced, dot-like lumps have become applied to the slice of bread within the selected area thereof. Especially when the perfo¬ rated plate or wall is in the form of wire mesh made from wire with a substantially circular cross-section, such dot-like lumps of the viscous material will be contiguous. The present invention also provides an apparatus for applying a layer of a viscous material to a slice of bread, said apparatus comprising a container for receiving the viscous material and including a per¬ forated plate or wall defining a multiplicity of small, closely spaced openings therein, means for pressing out the viscous material through said openings, and means for moving said slice of bread in relation to said perforated plate or wall, and the apparatus accord¬ ing to the invention is characterized in that said moving means are adapted to move said slice of bread and an abutment surface defined on the outer surface of said perforated plate or wall towards and away from each other, and in that control means for controlling the function of said pressing-out means and said moving means are pro¬ vided so that the viscous material is pressed through said openings while said slice of bread is maintained in abutting engagement with said abutment surface of said moving means. The invention will now be further described with reference to the drawings, wherein Fig. 1 is a diagrammatic sectional view of an embodiment of the ap¬ paratus according to the invention, and Fig. 2 is a perspective view of part of the apparatus shown in Fig. 1. The apparatus shown in the drawings is adapted to apply a layer of butter, margarine, or fat to a desired area of a slice of bread 10. However, the apparatus may also be used for applying other types of viscous material, such a marmalade, liver paste, cheese spread, and other paste-like foodstuffs. The apparatus shown in the drawings comprises a bottom frame 11 de¬ fining a bottom opening over which a wire mesh 12 has been stretched. A diaphragm frame 13 is arranged on the bottom side of the wire mesh and is clamped between the wire mesh and a supporting frame 14. The diaphragm frame 13 which is preferably replaceable, defines a central diaphragm opening 25, which corresponds to the area of each slice of bread to which a layer of butter or another viscous material is to be applied. A plunger or scraper 15, which is displaceably guided in guide channels 16, Fig. 2, formed at the inner side of the bottom frame 11, is mounted in the bottom frame 11 so that the scraper or plunger may be reciprocated as indicated by arrows 17 while being in , / contact with the upper side of the wire mesh 12, for example by means of a pneumatic or hydraulic cylinder 26. The plunger or scraper 15 may be moved between an inner position, in which at least the di¬ aphragm opening 25 of the diaphragm frame 13 is completely covered by the underside of the scraper or plunger 15, and an outer position in which the diaphragm opening is completely uncovered. The scraper or plunger 15 has a wedged front portion with an upwardly facing bev¬ elled surface 18. A receptacle 19 for the viscous material 20 to be applied to the bread slices 10 is replaceably mounted on the bottom frame 11. As shown in Fig. 1 the receptacle 19 may be retained on the bottom frame 11 thereby that the lower part of the receptacle 19 is received in the bottom frame and in a mounting collar 21, which has an angular cross-section and which is mounted on the top surface of the bottom frame 11. The slices of bread, to which a layer of the viscous material 20 is to be applied by means of the apparatus described above, are succes¬ sively moved past the bottom surface of the wire mesh 12 and the di¬ aphragm frame 13 by means of suitable conveyer means (not shown) . The conveyer means successively moves the bread slices 10 on to a sup¬ porting plate 22. When a bread slice has been placed on the support¬ ing plate 22 it is moved into abutting engagement with the wire mesh 12 exposed in the diaphragm opening 25 when the plunger or scraper 15 is in its inner position. The supporting plate 22 and the slice of bread arranged thereon may, for example, be moved by means of a pneumatic or hydraulic cylinder 27. Alternatively, the apparatus may be moved downwards into contact with the slice of bread 10. While the slice of bread is maintained in contact with the wire mesh the plunger or scraper 15 is moved from its inner to its outer position, and the vacuum which is thereby created in the bottom frame causes the viscous material 20 to be sucked into contact with the upper side of the wire mesh 12. When the plunger or scraper is thereafter moved from its outer to its inner position while the slice of bread 10 is still maintained in contact with the bottom side of the wire mesh, part of the viscous material will be pressed out through the openings in the wire mesh and into contact with the slice of bread 10. There¬ by, a uniform layer of the viscous material 20 is applied to the bread in an area defined by the diaphragm opening 25. While the plunger 15 remains in its inner position the bread is removed from the wire mesh 12, whereby the viscous material located within the openings of the wire mesh and adhering to the bread is drawn out from the openings, when the slice of bread is removed. The slice of bread may be removed from the wire mesh by lowering the plate 22 supporting the slice of bread by means of the hydraulic or pneumatic cylinder 27, or by lifting the apparatus, for example by means of other hy¬ draulic or pneumatic cylinders, not shown. A slice of bread 10 to which the viscous material has been applied is then released from the bottom side of the wire mesh 12 by means of a releasing fram 23, which is mounted in the supporting frame 14 and biased downwards by means of springs 24. The slice of bread 10 to which a layer of vis¬ cous material has been applied and which has now been released from the wire mesh is now removed from the supporting plate 22 and removed from the apparatus by means of suitable conveyer means, not shown. Another slice of bread 10 may now be moved to the supporting plate 22 and be moved into contact with the bottom side of the wire mesh 12 so that the springs 24 are compressed, when the scraper or plunger 15 is still in its inner position. The scraper or plunger 15 is now once more reciprocated ^ whereby the process described above is repeated. The movement of the cylinders 26 and 27 and of any other conveyer means may, for example, be- controlled by means of electronic control means 28, which may control the supply of pressure medium to the cylinders 26 and 27. EXAMPLE A layer of butter was applied to substantially square slices of bread by means of an apparatus as that shown in the drawings. In order to obtain a suitable viscosity creamed butter was used and maintained in the receptacle 19 of the apparatus at a temperature of about 25°C. The dimensions of the diaphragm opening 25 of the apparatus and, consequently, of the area of each slice to which butter was applied, were 100x100 mm. The wire mesh used was a smooth, stainless acid- resistant wire mesh in which the total area of the openings therein amounted to about 50% of the total area of the wire mesh. The wire thickness of the mesh was 0.26 mm and the size of the meshes or the spacing of the wires was 0.58 mm. The wire mesh in question is marketed by A/S Tekma, Hvidovre, Denmark, under the article number 79005830 and the mesh number 30. About 2 grams of butter was applied to each slice of bread, and the butter was applied as a smooth, uni- form layer in the area desired. It should be understood that various modifications of the embodiment shown in the drawings could be made within the scope of the present invention. As an example, the viscous mass 20 may be pressed out through the wire mesh 12 by other means than the scraper or plunger 15 shown. Thus, the necessary pressure may be obtained by means of a piston exposed to spring action or pressurized air, or the viscous mass in the receptacle 19 may be exposed directly to pressurized air. It is also possible to use a scraper or plunger shaped in another manner than that shown. Furthermore, it is possible to use the ap¬ paratus described to apply a viscous mass of any kind, and the layer thickness desired may be obtained by choosing a suitable wire mesh or perforated plate and a suitable pressure. In case it is desired to apply a relatively thick layer of a viscous material, such as cheese spread, liver paste, honey, or another kind of a viscous spread, it may be desirable to place the slice of bread at a smaller distance closely spaced from the abutment surface formed by the wire mesh or the perforated plate so that the viscous material is almost extruded into contact with the bread.

Claims: CLAIMS 1. A method of applying a layer of a viscous material (20) to a slice of bread (10) b pressing the material through a multiplicity of small, closely spaced openings defined in a perforated plate or wall (12), characterized in that a surface part of said slice of bread (10) is placed in substantially abutting engagement with an abutment surface defined by the outer surface of said perforated plate or wall (12) while the viscous material (20) is pressed out through said openings, and in that said slice of bread (10) is thereafter removed from the abutment surface by a relative movement of said slice, of bread and said abutment surface in a direction transversely to the abutment surface. 2. A method according to claim 1, characterized in that the direction of said relative movement is substantially at right angles to the abutment surface. 3. A method according to claim 1 or 2, characterized in that said perforated plate or wall (12) is formed by a substantially plane, stretched wire mesh. 4. A method according to any of the claims 1-3, characterized in that the viscous material (20) is pressed out through the openings in said perforated plate or wall (12) by means of a scraping member (15) , which is moved along the inner side of said plate or wall in abutting engagement therewith. 5. A method according to claim 4, characterized in that said scraping member (15) is moved between a first position in which the openings of said plate or wall (12) are uncovered by the scraping member while the inner side of the plate or wall is covered by said viscous material (20) , and a second position in which the inner side of the plate or wall is covered by the scraping member, and in that said slice of bread (10) is placed in abutting engagement with said abutment surface while said scraping member (15) is its said second position, and is removed therefrom when the scraping member has passed its said first position and has returned to its second position. 6. An apparatus for applying a layer of a viscous material (20) to a slice of bread (10), said apparatus comprising a container (11,19) for receiving the viscous material and including a perforated plate or wall (12) defining a multiplicity of small, closely spaced open¬ ings therein, means (15) for pressing out the viscous material (20) through said openings, and means for moving said slice of bread 10) in relation to said perforated plate or wall (12) , characterized in that said moving means (22-24,27) are adapted to move said slice of bread (10) and an abutment surface defined on the outer surface of said perforated plate or wall (12) towards and away from each other, and in that control means (28) for controlling the function of said pressing out means (15) and said moving means (22- 24,27) are provided so that the viscous material (20) is pressed through said openings while said slice of bread (10) is maintained in abutting engagement with the abutment surface by said moving means (22-24,27). 7. ' An apparatus according to claim 6, characterized in that said perforated plate or wall (12) is formed by a substantially plane, stretched wire mesh. 8. An apparatus according to claims 6 or 7, characterized in that said pressing means comprises a scraping member (15) , which is movable along the inner side of said perforated plate or wall (12) . 9. An apparatus according to claim 8, characterized in that said scraping means (15) has such a size and shape that it may cover substantially all of said openings in the perforated plate or wall (22) at the same time, and in that displac¬ ing means (26) are provided for displacing said scraping member (15) between a first position in which said openings in the plate or wall (12) are uncovered by the scraping member (15) , and a second position in which said openings are covered by the scraping member (15) at the same time. 10. An apparatus according to claim 9, characterized in that the control means (28) are adapted to control the function of said moving means (22-24,27) so that said slice of bread (10) is placed in abutting engagement with said abutment sur¬ face when the scraping member (15) is in its said second position, and so that said slice of bread (10) and said abutment surface are moved away from each other when said scraping member (15) has re¬ turned to said second position after having passed its said first position. 11. An apparatus according to any of the claims 6-10, characterized in that said moving means comprise one or more movable slice releasing members (23) which are mounted along and outside the circumference of said abutment surface, said slice releasing members being biased away from the abutment surface and mounted so that the rim portion of said slice of bread (10) is pressed into engagement with said releasing members when the slice of bread is moved into abutting engagement with said abutment surface.

Inventors: HENRIKSEN OLE, JACOBSEN BIRGER CARL, HENRIKSEN, OLE, JACOBSEN, BIRGER, CARL
Applicants: NEWMAC A S, NEWMAC A/S
Application year: 1986
Main classification: A23P1
IPC codes: A21C9, A21C15, A23G3, A47J9