Apparatus and method for dividing and cutting dough and the like

Abstract: An apparatus and method for dividing a mass of dough into a plurality of individual streams by means of a manifold (22) and fine tuning the flow rate of the individual streams by weir type diaphragm valves (27) so the streams have identical flow rates. Each of the individual streams of dough are simultaneously cut into identical dough pieces by a rotating driver (38) by a four-bar link mechanism.

Description: This invention relates to an apparatus and method for dividing a continuous stream of dough and the like into multiple continuous streams which are simultaneously extruded and are cut-off by a cutting mechanism to provide pieces to be baked into buns, rolls and the like having predetermined weights of uniform density and texture. The apparatus and method may also be used for other materials that are similar to dough and its characteristics. The invention is an improvement on the apparatus and methods disclosed in U.S. Patents 4,332,538, 4,424,236, 4,449,908 and 4,517,212 which are referred to herein and incorporated by reference. These prior patents show a double auger type of dough pump and divider which takes a mass of dough in bulk form and pumps it through in a single extruder or dispensing nozzle where it is cut into uniform pieces by a cutter moving across the dispensing nozzle. A very important criterion for a successful machine and method for producing dough pieces in large quantities is to provide pieces which are uniform in weight for subsequent handling and baking. GB-A-2,098,534 discloses apparatus for dividing a mass of dough into a plurality of smaller volumes of substantially uniform weight, by passing dough from a chamber through a plurality of extruder openings and partially occluding the area of each opening to try and achieve the desired the desired uniformity. EP-A-0238798 also discloses apparatus for dividing a mass of dough into smaller volumes. Dough fed to a chamber is taken from that chamber by a plurality of dual extruders, the extruders of each pair extending in opposite directions. Adjustment means are provided for balancing the flow between the extruders of each pair. The invention seeks to effect division of dough in an improved manner, leading to a higher degree of uniformity. According to a first aspect of the invention apparatus for dividing a mass of dough or the like into a plurality of smaller volumes of substantially uniform weight comprises feed means for providing a flow of pressurised dough; dividing means for dividing the flow into a number of smaller streams of dough and for controlling the streams; an extruder opening for each stream; and cut-off means arranged to cut-off the dough being discharged from each of the extruder openings into a plurality of pieces of subtantially uniform weight; characterised in that the feed means comprises a conduit through which the full volume of dough flows under pressure and with substantially uniform density; and in that the dividing means comprises a manifold assembly having an inlet connected to the conduit to receive therefrom the full volume of dough under the above mentioned pressure, and a plurality of divider conduits each connected to the manifold assembly to receive therefrom one of a plurality of substantially equally divided smaller streams of dough under the above mentioned pressure; each of the divider conduits having associated therewith an individually adjustable restrictor for effecting minor adjustment of each respective smaller stream so that all will flow at substantially the same rate; the restrictors being upstream of and separated from the extruder openings. According to a second aspect of the invention a method of dividing a mass of dough or the like into a plurality of smaller volumes of substantially uniform weight comprises providing a flow of dough; dividing the flow into a plurality of smaller streams and controlling the smaller streams; discharging each smaller stream through an extruder opening, and cutting each smaller stream on a periodic basis as it discharges from the extruder opening to provide a plurality of pieces of subtantially uniform weight; characterised in that a single flow of dough of substantially uniform density is continuously moved under pressure from a dispensing conduit (12) into a manifold assembly (22); the flow is divided into a plurality of substantially equal smaller streams each moving under the above mentioned pressure from the manifold assembly and along a respective one of a plurality of divider conduits (26) at the same approximate rate; each stream is restricted as needed by an individually adjustable restrictor (27) associated with the respective divider conduit to fine tune the flow rate of each stream to make them all flow at substantially the same rate; and each stream is continuously moved under the above mentioned pressure from the adjustable restrictor downstream to the extruder opening. The restrictors are desirably the weir type of diaphragm sanitary valves which utilize a polytetrafluoroethylene (PTFE) coated diaphragm. These valves control the velocities of the dough to the multiple discharge ports at the cut-off section and provide a relatively straight line adjustment control so that the amount of movement of the valve adjustment means causes a similar relative amount of throttling. The valves used are available from several sources but one of the preferred types of valves are the Saunders weir type diaphragm valves produced by the Saunders Valve, Inc., 15760 West Hardy Road, Houston, TX 77060. Desirably no lubricating oil is utilized, except for the first run which is wiped off immediately by the first dough passing through the apparatus. This allows buns with a uniform colour to be baked from the dough. The tight tolerances of the finished pieces greatly improve the subsequent automatically handling of the pieces for the baking operation and packaging. The invention is of special value in producing hamburger buns in large quantities. The features of the invention will become more apparent upon reading the following specification, when taken in conjunction with the accompanying drawings in which: FIG. IA is a plan view of apparatus according to the invention assembled with the auger feed; FIG. IB is a side view of FIG. IA; FIG. IC is the end view from the right side of FIG. IB; FIG. 2 is an enlarged plan view of the left portion of FIG. IA; FIG. 3A is an enlarged side view of the left portion of FIG. IB; FIG. 3B is a schematic of the cross section of the valve shown in FIG. 3A; FIGS. 4A, 4B, 4C and 4D are schematics showing the progressive action of the cut-off knife; FIG. 5 is a front elevational view of the cutter and drive mechanism; and FIG. 6 is a side view of FIG. 5. Referring now in more detail to the drawings, there is shown in FIGS. IA, IB and IC, the dough dividing apparatus 10 having a hopper 11 and an auger inside a trough and tunnel 12. The trough is the portion under the hopper outlet and the tunnel is the portion to the left of the trough. Although the drawings show approximately four threads of the flight of the auger in the tunnel, it is preferable to use only slightly more than two threads. The auger is a double juxtaposed pair of augers which are driven by a main drive 13 through a belt drive 14 and drive gear box 15. The dough is continuously extruded to the left through a transition block 16 to a cut-off knife assembly 17. The apparatus has a support frame 18. The dough is homogenized to a uniform texture and density by the augers in the tunnel prior to the continuous exit of the dough through the transition block 16 to the metering pump 19 which has an outlet conduit. The metering pump is driven by a motor 20 to a gearbox 21. With reference to FIGS. IA, IB and 2,the continuous stream of dough being transmitted through the outlet conduit of the metering pump 19 is fed into a manifold assembly 22 which divides the dough into six continuous streams of dough. Usually, this is four, six or eight streams and of course, can be a fewer or a larger number of multiple streams. The manifold assembly 22 has an inlet 23, a header 24, and end divider curved conduits 25 at each end. Exiting from the manifold 24 are also four straight intermediate divider conduits 26. Each of the six divided streams has a restrictor in the form of valve assembly 27 which is preferably the weir type of diaphragm valve having a PTFE coated diaphragm as mentioned above. Exiting from each of the valves is an extruder conduit 36 which exits into the cut-off knife assembly 17 which will later be described more fully. The revolutions per minute of the augers 12 is typically 50 to 125 rpms. This is generally less than the speed of the augers when larger pieces of dough are being provided such as for loaves of bread as typically the invention herein is used for the smaller pieces of dough such as 28.4 to 85.2 g (1 to 3 ounces) for rolls and buns. Of course, the size of the dough pieces and their ultimate use should not be taken as a limitation on the invention as both smaller and larger pieces can be handled. The diameter of the inlet conduit to the manifold and the manifold header is 5.08 cm (2 inches) and the end divider curved conduits 25; straight immediate divider conduits 26 and the extruder conduits 36 are all 3.81 cm (1½ inches) in diameter. Preferably, the conduits are made of stainless steel. With reference to FIG. 3B, there is shown a cross section of the preferred weir type of diaphragm valves assembly 27 which forms an adjustable restrictor to fine tune the rate of flow of the continuous streams of dough after they have been divided by the manifold assembly 22. The valve assembly 27 has two connector clamps 28 which are designed for quick connect and disconnect. The valve is operated by a hand wheel 29 which has three turns or 720° from full closure to full opening. This permits fine adjustments of the throttling action of the valves. The valve also includes a bonnet 30, a screw stem 31 and a diaphragm plate 32 designed to mate with the diaphragm seat or weir 35 when the valve is fully closed. The valve has a diaphragm 33 which is coated on the inside with PTFE. The flow arrows in FIG. 3B show that the dough is progressively throttled as it passes through the valve. Other types of valving may be used to provide the throttling action provided they can be finely adjusted but the weir type of diaphragm valve is the preferred one as it provides an easy passage for the dough through the valve with minimum turbulence, is readily sanitized and can be relatively easily adjusted. If dough was absolutely constant, it could be theoretically divided into the multiple streams having equal velocities without the need for the valving just by designing the manifold assembly with the special characteristics needed. However, this does not work out as dough such as used in the production of buns and rolls is compressible pursuant to the action of yeast. The many various forms and consistencies of dough used in the production of buns and rolls relative to absorption and ingredients that serve to give the product unique flavours and textures, etc., along with the variable velocities required for differently weighted dough pieces, make the design of a perfect manifold impractical. Dough, being a flowable paste material, does not occupy a place on available viscosity charts. This further complicates the design of a manifold that would present the flow divider with uniform pressures and velocities to the cut-off assembly for separation into smaller volumes. The principle separation of the dough into multiple streams is provided by the manifold assembly but it is essential that each of these streams also be fine tuned as to constant velocity of the dough by means of the throttling valves. With reference to FIGS. 3A and 3B, each of the extruder conduits exit into an extruder plastic termination section or extruder block 37 located in the cut-off knife assembly 17. The extruder plastic termination section has an extruder nozzle with an outlet rim in a common plane on the face 58 of the plastic termination section as best seen in FIG. 6. With reference to FIGS. 3A, 5 and 6, there is shown the cut-off knife assembly where a knife drive motor 38 drives a knife gear box 52 which has a double output shaft. Each output shaft is coupled by coupler 41A to the knife drive shaft 39. The knife drive shaft 39 rotates at a constant predetermined speed and drives knife drive link 40 keyed thereto. Drive link 40 has a drive link pivot 41 at the end remote from said shaft end. Carried by the drive link pivot 41 is a knife carrying or driven link 42. At the end of the driven link 42 is a second pivot 43 and beyond that pivot and adjacent thereto is mounted the cut-off knife 44 which is attached to the driven link 43 by bolts 57. The cut-off knife has a cutting edge 54. A third link 45 is pivoted to the second pivot 43 at one end and to a fixed pivot 46 at the other end. The centre of the shaft 39 and the third link fixed pivot 46 are fixedly located on the cut-off knife assembly so that the assembly itself provides a fixed link between these two pivot points so that it may be referred to as a four-bar link mechanism. The cut-off knife assembly has a protective cover 47 which is shown in the down and safe position in FIG. 3A but is omitted for purposes of clarity in FIGS. 5 and 6. The outboard end of drive shaft 39 is supported by carrying bearings 53. As best seen in FIG. 6, the extruder plastic termination section 37 is held to the cut-off blade assembly 17 by bolts 56. The plastic termination section has a face 58 lying in a common plane with the six extruder nozzles. As best seen in FIG. 5, the cut-off blade 44 is 0.95 cm (3/8th inch) thick, 10.16 cm (4 inches) high and 68.58 cm (27 inches) wide so that all six extrusions are cut-off simultaneously by the single blade. While the blade 44 and the plastic termination section 37 can be made of other materials, preferably they are made of ultra-high molecular density plastic or UHMD polyethylene. This does not require lubrication after long time runs and there is little or no dough build up. Also shown in FIG. 6, is the tube and shoulder 55 of the termination of the extruder conduit 36. The cut-off knife makes approximately 100 cuts per minute which can be readily varied up to 150 cuts per minute and reduced to fewer cuts per minute. At 150 cuts per minute, 900 dough pieces per minute are produced. With references to FIGS. 4A-4D, there is shown the sequence of cutting actions of the cut-off blade assembly. The shaft 39 rotates at a constant predetermined velocity in a counter-clockwise direction carrying with it the drive link, driven link and third link. The unique multiple functions of the four-bar link mechanism to which the cut-off knife is attached dictates its motion and path. FIG. 4A shows a straight line motion of the knife for about 55° of rotation of the driver link as it cuts off the extruded dough piece 48. Previously cut off dough pieces 49 are shown on the conveyor belt 51 which is supported in position by the conveyor roller 50. It should be noted that the freshly extruded dough piece 48 just prior to being cut-off is of a larger diameter than the conduit from which it is extruded. This relates to the characteristic flow of dough and the fact that the dough includes gases therein which were under pressure just prior to the extrusion. The knife velocity at the point shown in FIG. 4A is close to the velocity of the driver link where it joins the driven link. With reference to FIG. 4B, there is shown how the cut-off knife controls the movement of the product. As the dough pieces are cut-off and deposited on the conveyor belt, they are accelerated by the motion of the knife in the direction of the conveyor belt travel. With reference to FIG. 4C, there is a velocity change as the knife first accelerates outward and upward, urging the current dough piece in the direction of the conveyor belt travel, then decelerates to the top of the knife's path completely clearing the extrusion port to make clearance for the subsequent dough piece being extruded. The increase in dwell across the top of the knife path allows for the extrusion of larger pieces of dough to be made without interfering with the knife at this stage of the cycle. With reference to FIG. 4D, there is a further depiction of the path change as the knife starts downward, accelerating to the point of straight line motion as it engages the cutting plane of the dough piece just above the discharge port. The uniform spacing of the dough pieces along the conveyor belt should be noted as previously such spacing was not normally attained. The described apparatus permits a much better control of the manufacturing process downstream from the apparatus. There has thus been described a unique apparatus and method for providing multiple dough pieces having a uniform texture and weight, free from lubricating oil and uniformly placed on a conveyor belt.

Claims: Apparatus for dividing a mass of dough or the like into a plurality of smaller volumes of substantially uniform weight comprising feed means (11,12) for providing a flow of pressurised dough; dividing means (22 to 26) for dividing the flow into a number of smaller streams of dough and for controlling the streams; an extruder opening for each stream; and cut-off means (44) arranged to cut-off the dough being discharged from each of the extruder openings into a plurality of pieces of subtantially uniform weight; characterised in that the feed means comprises a conduit (12) through which the full volume of dough flows under pressure and with substantially uniform density; and in that the dividing means comprises a manifold assembly (22) having an inlet (23) connected to the conduit to receive therefrom the full volume of dough under the above mentioned pressure, and a plurality of divider conduits (26) each connected to the manifold assembly to receive therefrom one of a plurality of substantially equally divided smaller streams of dough under the above mentioned pressure; each of the divider conduits having associated therewith an individually adjustable restrictor (27) for effecting minor adjustment of each respective smaller stream so that all will flow at substantially the same rate; the restrictors being upstream of and separated from the extruder openings. Apparatus as claimed in claim 1 in which each restrictor (27) is designed to effect progressive restriction of the dough as it passes through the restrictor. Apparatus as claimed in claim 1 or claim 2 in which each restrictor (27) is a weir type diaphragm valve. Apparatus as claimed in any one of the preceding claims in which each restrictor (27) has a surface of polytetrafluoroethylene adjacent the dough. A method of dividing a mass of dough or the like into a plurality of smaller volumes of substantially uniform weight comprising providing a flow of dough; dividing the flow into a plurality of smaller streams and controlling the smaller streams; discharging each smaller stream through an extruder opening, and cutting each smaller stream on a periodic basis as it discharges from the extruder opening to provide a plurality of pieces of subtantially uniform weight; characterised in that a single flow of dough of substantially uniform density is continuously moved under pressure from a dispensing conduit (12) into a manifold assembly (22); the flow is divided into a plurality of substantially equal smaller streams each moving under the above mentioned pressure from the manifold assembly and along a respective one of a plurality of divider conduits (26) at the same approximate rate; each stream is restricted as needed by an individually adjustable restrictor (27) associated with the respective divider conduit to fine tune the flow rate of each stream to make them all flow at substantially the same rate; and each stream is continuously moved under the above mentioned pressure from the adjustable restrictor downstream to the extruder opening. A method according to claim 5 in which each smaller stream is progressively restricted in its flow through the adjustable restrictor. A method according to claim 5 or claim 6 wherein the moving dough is processed without any lubricating oil so that the final product can be baked with uniform browning.

Inventors: CUMMINS DONALD L, CUMMINS, DONALD L.
Applicants: AMF MACHINERY SYSTEMS INC, AMF MACHINERY SYSTEMS, INC
Application year: 1990
Main classification: A21C5
IPC codes: A21C5, A21C3, A21C11