APPLICATION OF A SHEET TO A CAKE OF MATERIAL

Abstract: A stack (27) of sheets is supported with one end exposed and facing a conveying drum (13) having a cavity (17) containing a raw hamburger (22). The stack is urged towards the drum so as to bring the exposed sheet (36) into contact with the exposed surface of the raw hamburger (22). While they are in mutual contact, an impulse is applied to the stack (27) towards the drum (13), by an inertial mass (41) via a cranked arm (42) striking a pusher plate (37), so as to cause the exposed sheet (36) to adhere to the raw hamburger (22) and be carried away from the stack.

Description: Application of a Sheet to a Cake of Material This invention relates to.a method and apparatus for applying a sheet, e.g. of paper, to one side of a cake of material, e.g. a raw hamburger. A hamburger papering machine is known in which a paper is picked up from a stack of papers and is transported to a position at which it is applied to one side of a raw hamburger produced by the machine. The sheet transport mechanism is complicated and bulky, and the machine is costly. The present inventio is based on the idea of using the raw hamburger (or similar cake of material) to pick up a single sheet directly from a stack of sheets. The invention provides apparatus for applying a sheet to one side of a cake of material, comprising: conveying means defining a cavity for carrying the cake with one surface exposed; supporting means for supporting a stack of sheets with a sheet being exposed at one end of the stack and facing the conveying means; urging means for urging the stack towards the conveying means; and means for applying an impulse to the stack towards the conveying means while the exposed sheet and the exposed surface are in mutual contact, so as to cause the exposed sheet to adhere to the cake and be carried away from the stack. Preferably, the urging means causes the downstream region of the exposed sheet of the stack to project from the supporting means towards the conveying means so that the middle and downstream regions of the exposed sheet are brought into contact with the middle and leading regions of the exposed surface of the cake. For the same reason, it is preferable for the cake to have a bulge in' the leading region of its exposed surface. Preferably the supporting means supports the stack so that its sheets are approximately vertical. The supporting means preferably carries guide means for guiding the leading edge of the exposed sheet towards the conveying means downstream of the supporting means. The apparatus may comprise supply means for supplying the said material to the cavity upstream of the stack of sheets so as to form the cake in the cavity. Preferably the supply means comprises a duct defining a passage having an inlet end remote from the conveying means and an outlet end adjacent the conveying means, and means for supplying the said material to the inlet end under pressure at least while the cavity is adjacent the duct. In a preferred embodiment the leading end portion of the cavity leaves the duct while the trailing end portion is still in communication with the outlet end of the passage, so that a bulge is formed in the leading region of the exposed surface of the cake. Preferably, the outlet end of the passage is longer than the inlet end and the cavity, considered in the conveying direction; the outlet end preferably has a region substantially corresponding in shape and size to the mouth of the cavity and a downstream extension, preferably of reduced width. The part of the duct adjacent the conveying means is preferably of plastics material and is preferably in contact with the conveying means. The urging means preferably comprises a pusher plate slidably suspended in its upper end region and acted on by spring means. It may be convenient to arrange for the supporting means to be moved towards the conveying means when the cavity is adjacent the supporting means and to be moved away after the impulse. The impulse may be applied to the stack by an inertial mass urged towards the rear of the stack (e.g. by a spring or by gravity) so as to apply the impulse to the stack (shortly after the support means, together with the stack, has been moved towards the conveying means). The inertial mass is preferably pivotally mounted and is preferably urged towards the stack by its own weight. Alternatively, the impulse may be applied by a pivotally mounted striking member actuated by a cam kinematically linked to the conveying means. The apparatus may also comprise a transverse element for scraping material from the conveying means downstream of the supporting means. Means are preferably provided for wiping the transverse element, preferably while the said element is lifted away from the conveying means. The conveying means preferably includes pushing means for ejecting the cake from the cavity downstream of the supporting means. The invention will be described- further, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic side view of part of an apparatus for applying paper sheets to raw hamburgers; Figures 2 and 3 are similar views of the apparatus at later stages in its operating cycle; Figure 4 is a side view of part of the apparatus shown in Figures 1 to 3, on an enlarged scale; Figure 5 is a rear end view of the part shown in Figure 4; Figure 6 is a plan view of part of the apparatus, showing a scraping device only partly shown in Figures 1 to 3; Figure 7 is a front end view of the part shown in Figure 6; Figure 8 is a plan view of another embodiment of the apparatus; Figure 9 is an end view on arrow IX in Figure 8; Figure 10 is an end view on arrow X in Figure 8; Figure 11 is a rear end view of an improved drum; and Figure 12 is a vertical section through the drum of Figure 11. The apparatus illustrated in Figures 1 to 7 has a stainless steel housing 1 containing a drive mechanism and supporting a circular stainless steel plate 2 with a rim 3 for holding a cylindrical removable hopper 4 to which raw hamburger material (mainly minced meat) is to be supplied.. A driven shaft 6 passing through the centre of the plate 2 carries upper and lower paddles 7 which carry the raw material round to an opening 8 in the plate 2 and which tend to compress the material downwards. A radial bar 9, removably fixed at the level of a gap between the paddles 7, prevents free circulation of the raw material, which is therefore forced into the opening 8, which is the inlet to a passage 11 in a plastics duct 12 fixed to the bottom of the plate 2. The lower end of the duct 12 is in contact with a stainless steel drum 13 mounted on a driven shaft 14 which rotates in synchronism with the paddle shaft 6. There is a recess 16 of constant depth, but whose width increases rearwardly, in the lower surface of the duct 12. The passage 11 is permanently filled with the raw material by the paddles 7. Surplus raw material carried round on the circumferential surface of the drum and not removed by the scraping device described below is taken into the passage 11 by the recess 16, which also serves as an air vent from the passage 11. The circumference of the drum 13 has a round cavity 17 of substantially constant depth, which passes the outlet opening 18 of the passage 11 at the same time that the paddles 7 are forcing the raw material into the inlet opening 8. The air gap provided by the recess 16 vents air from the rear of the cavity 17 during the initial stages of filling. The outlet opening 18 has a round region corresponding to the mouth of the cavity 17 and a downstream .extension 19 of reduced width (Figure 6). As shown in Figure 1, the leading end portion of the cavity 17 leaves the duct 12 while the trailing end portion is still in communication with the outlet opening 18 so that a bulge 21 is formed in the leading region of the exposed surface of the raw hamburger 22 (which is otherwise flush with the drum surface) . A bracket 23, removably fixed to the duct 12 by a bolt with a release knob 24, pivotally carries a support 26 holding a stack 27 of greaseproof paper sheets which are to be applied to the raw hamburgers. Each sheet consists of two separable layers, so that when a series of raw hamburgers with interposed sheets are frozen together, the hamburgers can be separated easily from one another. The stack 27 has a through hole receiving a rod 28 from which the sheets hang approximately vertically. The rod 28 engages a front wall of the support 26 and its rear end is received in a notch 29 in a rear wall of the support (Figure 5) and has a downwardly bent extension 31 which locates behind a lug 32 on the rear wall. A front end portion 33 (Figure 4) of the rod 28 has an upwardly directed knife-edge 34 to facilitate removal of the sheet 36 exposed at the front of the stack 27. The stack 27 is urged towards the drum 13 by a pusher plate 37 acted on by a leaf spring 38. Because the front face of the stack 27 is restrained .at the top ' but free at the bottom, the downstream portion of the exposed sheet 36 projects from the support 26 towards the drum 13. The bracket 23 carries a rotatable shaft 39 on which are fixed two weights 41 and a cranked arm 42 normally resting on the pusher plate 37 and thereby assisting in urging the stack 27 forwards (Figure 1). The support 26 is urged to the position shown in Figure 2 (in which it abuts against the bracket 23) by a tension spring 43 (Figure 5). It is normally held in the position shown in Figures 1 and 3 (in which it is pivoted downwards and away from the drum 13) by a cam follower 44 having a roller 46 which rests on the circumference of the drum 13. In the region of the cavity 17 the circumference of the drum is cut away to accommodate a cam 47 having a recess 48. The point in the drum rotation cycle at which the cam follower 44 enters the recess 48 is adjustable by pivoting the follower 44 about=an axis 49 (Figure 4). For this purpose the follower 44 has a lateral extension 51 which is acted on by a compression spring 52 on one side and an adjusting screw with a control knob 53 on the other side. As the cavity 17 containing the raw hamburger 22 comes into register with the stack 27 of sheets, the cam follower 44 enters the recess 48, thereby applying the middle portion of the exposed sheet 36 to the middle portion of * the exposed surface of the hamburger and at the same time (or slightly in advance) applying the downstream portion of the exposed sheet 36 to the bulge 21, as the support 26 moves to the position shown in Figure 2. In this position, the weights 41 have been left behind because of their inertia, and the arm 42 is therefore spaced from the pusher plate 37. Consequently, as the weights 41 fall (while the cam follower 44 is in the recess 48) the arm 42 delivers an impulse to the stack 27 via the plate 37, which impulse is transmitted to the exposed sheet 36, thereby causing it to adhere to the hamburger 22 and at the same time flattening out the bulge 21. The exposed sheet 36 is then carried away by the hamburger 22 (being torn from the rod 28) while the stack 27 and the support 26 are restored to the position shown in Figures 1 and 3 by the cam follower 44 leaving the recess 48. Since the impulse is of limited duration, the risk of more than one sheet being carried away is avoided. The speed of rotation of the drum must be sufficiently low that the cam follower 44 does not jump the recess 48 and sufficiently high that the arm 42 comes out of contact with the pusher plate 37. In the apparatus illustrated, the drum speed is approximately 40 rev/min. As the sheet 36 leaves the stack 27, before the support 26 has moved away from the drum 13, it is guided by a curved plate 54 on the bottom of the support 26. urging the leading edge portion of the sheet 36 firmly into contact with the hamburger. Thereafter a stationary cam 56 comes into contact with a following roller 57 on a plunger 58 which ejects the hamburger 22 from the cavity 17. The hamburger 22 is separated from the plunger by a scraping device 59 and falls, with the sheet 36 underneath, onto a belt conveyor (not shown) . The scraping device 59 (Figures 6 and 7) comprises a scraping wire 61 stretched between a pair of arms 62,63 which are rigidly mounted on a transverse member 64 pivotable about its own axis. One arm 62 carries a roller 65 which normally bears on the drum circumference, keeping the wire 61 away from the drum, but which enters a circumferential recess in the drum as the hamburger approaches and for a given time after the hamburger has been removed. While the wire 61 is out of contact with the drum 13 it is wiped by a plastics element 66 having a through-hole. The wiping element 66 is carried by an arm 67 which is slid horizontally to and fro in synchronism with the ro.tation of the drum. A preferred embodiment of the invention is illustrated in Figures 8 to 10, in which parts similar to those described above are given the same reference numerals. Parts of the apparatus which operate in the same way as in the apparatus of Figures 1 to 7 are not illustrated in detail in Figures 8 to 10 and/or are not described in detail below. Figures 8 to 10 show the apparatus at different times during its cycle of operation. The stack 27 of sheets is suspended from the rod 28 in a fixed support 126 and is urged towards the drum 13 by a pusher plate 137 acted on by two compression springs 138. In this embodiment the impulse is applied to the rear of the stack 27 by a curled leaf spring 151 carried by a metal plate 152 fixed on one end of a pivot shaft 153 whose other end bears an L-shaped actuating lever 154 having two arms 156,157. The lever 154 cooperates with an abutment 158 on an actuating member 159 pivoted about a shaft 161 and carrying a pin 162 connected to the lever arm 156 by a tension spring 163. The actuating member 159 carries a cam follower roller 164. The transverse member 64 of the scraping device carries an actuating arm 166 bearing a cam follower roller 167 and acted on by a tension spring 168. The wiper arm 67, slidably mounted on the transverse member 64, is linked by a rod 169 to a slider 171. A further rod 170 is pivoted at one end to the slider 171 and at the other end to one end of a cranked actuating lever 172 which pivots on a shaft 173 and whose other end bears a cam follower roller 174 and is acted on by a tension spring 176. The pivotal range of the lever 172 is limited by a pad 177 on a bracket 178. A shaft 114, which is an extension of the drum shaft 14 or is synchronised therewith carries a cam 179 formed with three cam surfaces, viz.. a radial cam surface 181 cooperating with the cam follower roller 164, a radial cam surface 182 cooperating with the cam follower roller 167, and an axial cam surface 183 cooperating with the cam follower roller 174. The cam surface 181 is cylindrical except for a raised portion defined by a boss 184. The boss 184 strikes the roller 164 when the stack 27 and the hamburger are in register, causing the actuating member 159 to tilt clockwise (in Figure 9) so that the abutment 158 strikes the lever arm 156 and thereby causes the shaft 153 to turn (anticlockwise in Figure 9 and clockwise in Figure 10) together with the plate 152 and leaf spring 151, which thus applies an impulse to the rear of the stack 27. Almost immediately, the roller 164 leaves the boss 184 and the actuating member 159 and the lever 154 are restored to the position shown in Figure 9 by the spring 163. The cam surface 182 is also cylindrical, except for a depression 186 which the roller 167 enters in order to bring the scraping wire 61 into contact with the drum 13. The cam surface 183 is flat except for a raised ramp 187 which acts on the roller 174 to cause the lever 172 to turn and to act on the wiper arm 67 via the linkage 170-171-169 so that the wire 61 is wiped while it is out of contact with the drum 13. Figures 11 and 12 illustrate an improved drum 213 applicable to the' embodiment of Figures 1 to 7 or the embodiment of Figures 8 to 10. The drum 213, which is open at its rear end 214, has a round cavity 217 defined by a cylindrical insert 215 in which a plunger 258 of plastics material is slidably mounted. An extension 260 of the plunger carries a following roller 257 which cooperates with the stationary cam 56 (Figures 1 to 3), Two parallel rods 261 extend from a transverse bar 262 (in which they are fixed by pins 263) through guideways 264 and are fixed in recesses in the extension 260 of the plunger 258 by easily removable pins 266 carried by a resiliently flexible wire 267 retained by a bracket 268. Thus, when the drum 213 is dismounted from the drive shaft, the pins 266 can be removed so that the plunger 258 can be easily taken out for cleaning or replacement. Two tension springs 269 urge the transverse bar 262 against an adjustable stop constituted by a captive nut 271 having opposed axial grooves receiving side members 272 which prevent its rotation. An axially fixed, rotatable screw 273 engages in the nut 271 and has a slotted head 274 which is operable from outside the drum (by a screwdriver or coin) so as to adjust the position of the nut 271 and consequently the retracted position of the plunger 258, which determines the depth of the hamburger in the cavity 217. All the parts of the drum in Figures 11 and 12, except the plunger, are of stainless steel. Various modifications may be made within the scope of the invention as described above. Instead of a raw hamburger a cake of any other suitable material may be formed, such as a fishcake, a pastry item, or a cake of animal and/or vegetable material. The cake need not be round, e.g. it can be square or oblong. Instead of greaseproof or waxed paper, it may be possible to use plastics sheets or metallic foils, of any convenient shape.

Claims: Claims 1. Apparatus for applying a sheet to one side of a cake of material, comprising: conveying means defining a cavity for carrying the cake with one surface exposed; supporting means for supporting a stack of sheets with a sheet being exposed at one end of the stack and facing the conveying means; urging means for urging the stack towards the conveying means; and means for applying an impulse to the stack towards the conveying means while the exposed sheet and the exposed surface are in mutual contact, so as to cause the exposed sheet to adhere to the cake and be carried away from the stack. 2. Apparatus as claimed in claim 1, in which the urging means causes the downstream region of the exposed sheet of the stack to project, from the supporting means towards the conveying means so that the middle and downstream regions of the exposed sheet are brought into contact with the middle and leading regions of the exposed surface of the cake. 3. Apparatus as claimed in claim 1, in which the supporting means supports the stack so that its sheets are approximately vertical. 4. Apparatus as claimed in claim 1, in which the supporting means carries guide means for guiding the leading edge of the exposed sheet towards the conveying means downstream of the supporting means. 5. Apparatus as claimed in claim 1, further comprising supply means for supplying the said material to the cavity upstream of the stack of sheets so as to form the cake in the cavity, in which the supply means comprises a duct defining a passage having an inlet end remote ' from the conveying means and an outlet end adjacent the conveying means, and means for supplying the said material to the inlet end under pressure at least while the cavity is adjacent the duct. 6. Apparatus as claimed in claim 5, in which the leading end portion of the cavity leaves the duct while the trailing end portion is still in communication with the outlet end of the passage, so that a bulge is formed in the leading region of the exposed surface of the cake. 7. Apparatus as claimed in claim 6, in which the outlet end of the passage is longer than the inlet end and the cavity, considered in the conveying direction. 8. Apparatus as claimed in claim 7, in which the outlet end of the passage has a region substantially corresponding in shape and size to the mouth of the cavity and a downstream extension, preferably of reduced width. 9. Apparatus as claimed in claim 1, further comprising a transverse element for scraping material from the conveying means downstream of the supporting means, and means for wiping the transverse element, the wiping means operating while the transverse element is lifted away from the conveying means. 10. Apparatus as claimed in claim 1, including means for moving the supporting means towards the conveying means when the cavity of the conveying means is adjacent the supporting means, and means for moving the supporting means away from the conveying means after application of the impulse. 11. Apparatus as claimed in claim 1, in which the means for applying an impulse to the stack comprises an inertial mass urged towards the rear of the stack, e.g. by its own weight. 12. Apparatus as claimed in any of claims 1 to 20, in which the means for applying an impulse to the stack comprises a pivotally mounted striking member, preferably comprising a leaf spring carried by a plate, actuated by a cam kinematically linked to the conveying means. 13. Apparatus as claimed in claim 12, in which the conveying means is mounted on one side of a housing containing a drive mechanism, the opposite side of the housing having mounted thereon the said cam kinematically linked to the conveying means. 14. Apparatus for applying a sheet to one side of a cake of material, comprising a drum having in its circumference a cavity for carrying the cake with one surface exposed; means for rotating the drum in a given conveying direction; supply means for supplying the material to the cavity so as to form the cake in the cavity; supporting means for supporting a stack of sheets with a sheet being exposed at one end of the stack and facing the circumference of the drum. downstream of the supply means; urging means for urging the stack towards the drum; means for moving the supporting means towards the drum, when the cavity is adjacent the supporting means, so as to apply an impulse to the stack towards the drum while the exposed sheet and the exposed surface of the cake are in mutual contact, thereby causing the exposed sheet to adhere to the cake and be carried away from the stack; means for moving the supporting means away from the drum after application of the impulse; and pushing means within the drum, for ejecting the cake from the cavity downstream of the supporting means. 15 A method of applying a sheet to one side of a cake of material, comprising providing a cake of material, e.g. a raw hamburger, in a cavity in a conveying means moving in a conveying direction, supporting a stack of sheets with a sheet exposed at one end of the stack and facing the conveying means, urging the stack towards the conveying means, and applying an impulse to the stack towards the conveying means while the exposed sheet and the exposed surface are in mutual contact, so as to cause the exposed sheet to adhere to the cake and be carried away from the stack. 16. A method as claimed in claim 15, in which the cake has a bulge in the leading region of its exposed surface.

Inventors: CROSS MAURICE WILLIAM EDWARD, CROSS, MAURICE, WILLIAM, EDWARD
Applicants: CROSS MAURICE WILLIAM EDWARD, CROSS, MAURICE, WILLIAM, EDWARD
Application year: 1987
Main classification: B65B25
IPC codes: B65B25