STRESS FREE DOUGH SHEETING PROCESSOR FOR BATCH SYSTEMS

Background of the Invention

This invention relates to an apparatus and method for producing

a continuous sheet of dough. More particularly, this invention relates to

an apparatus and method for producing a continuous sheet of stress free

dough of generally uniform height and width from discrete batches of dough.

The current practice for commercially producing sheets of dough

by a batch method generally involves measuring the required dry

ingredients (i.e. , flour, sugar, yeast, etc.) and mixing them with the

appropriately measured liquid ingredients (i.e., water, oii, etc.). The resulting dough paste created by mixing these ingredients is then

kneaded until the desired dough batch is developed. A gluten network

is formed within the dough batch.

The dough batch is typically then transferred to a retention hopper

or bin and co-mingled with previously prepared batches of dough. The

dough remains in the retention hopper until it is extruded by a

combination of peripherally ribbed oppositely rotating discnarge rollers which force the dough mass through an extrusion die or restricted

oDening to form a continuous stream of dough exiting the retention bin.

In the course of forcing the dough through the extrusion die, the

discharge rollers forcefully pull the dough from the retention hopper and

push it through the restricted opening. Once extruded, the stream of

dough can be shaped, rolled, or cut to the desired specifications

depending upon the ultimate dough product (i.e. , croissant, bread loaf,

biscuit, pizza dough, etc.).

As the dougn is kneaαed. the gluten networκ develops within the

dough. The gluten network is a highly elastic and cohesive gel structure

which is generally indicative of the quality of the dough. The more

developed and undamaged the gluten network remains in the dough, the higher the quality of the resulting dough product. The gluten in the dough is damaged or destroyed as a result of high stresses or shear forces applied to the dough. Therefore, the less stress imparted to the

dough or the more "stress free" the dough remains, the higher the

quality of the resulting dough product.

In the practice of the above-described commercial process for producing a continuous sheet of dough, the peripherally ribbed discharge

rollers which pull the dough from the retention hopper and force it

through the extrusion die exert a significant sheer or tearing force upon

the dough. These forces greatly damage and destroy the gluten network

within the dough. Additionally, the compression forces applied to the

dough bv the discharge rollers also damage the gluten network. The resulting stream of compressed dough emerging from the retention

hopper -~ difficult to shape and form due to the damaged gluten network.

The damaged dough can be partially restored if passed through a series of rollers and shapers, but this corrective measure is much more

timely and costly than if the gluten network had never been damaged in

the first place. An additional corrective measure to rehabilitate the

damaged gluten common in the industry is to allow the dough to rest for

as much as two hours after extrusion from the retention hopper. Once again, this practice serves to only partially regenerate the gluten network and is inherently time consuming and is a further complicating

requirement in producing a continuous sheet of quality, stress free

dough. The dough, even after rehabilitation, is of a lesser quality and

more resistant to shaping than "stress free" dough.

One prior solution for producing a continuous stream of stress free

dough is disclosed in U.S. Patent Application Serial No. 07/985,551 ,

assigned to the Assignee of this invention. That invention involves

continuously mixing the dry and liquid ingredients which are then transferred to a temperature controlled chamber for continuous kneading

which generates a continuous stream of dough. The dough stream is

discharged from the kneading chamber, without the benefit of rollers or stress inducing extrusion dies, through a discharge conduit of predetermined flow resistance. The resulting stress free continuous

dough stream has a well developed and undamaged giuten network.

However, the apparatus and method disclosed in that application is

directed to a continuous mixer and continuous kneader for forming a

continuous dough sheet. There still exists a need for a method and

apparatus for producing a continuous sheet of stress free dough for the batch process in which the ingredients are mixed and then kneaded and

discrete batches of dough deposited and co-mingled with other batches

in the retention hopper. A batch system for producing dough includes

a batch mixer in which the dough is mixed and then kneaded. Batch sizes typicaily vary from as little as 1 00 pounds to as much as 2,000

pounds per batch.

A method for producing a continuous sheet of dough for the batch

process is disclosed in U.S. Patent No. 4,904,491 in which the dough is severed into portions by horizontal cutter blades positioned at the bottom of a hopper. In this method, the dough is produced in batches which are then deposited into the hopper. The cutter blades section the

dough into individual portions which are each then weighed and placed on a conveyor to occupy a space proportional to their weight. The

speed of the conveyor is controlled to correspond to the weight of each

portion of dough so that each successive portion is positioned on the

conveyor to overlap the previous portion, thereby forming a continuous

sheet of dough after rolling and shaping. A problem associated with this method is the involved steps of weighing each portion of dough and regulating the conveyor to overlap each portion. These steps complicate

the dough sheeting process. Therefore, the cost of such a system t carry out the method disclosed in Patent No. 4,904,491 can be

prohibitive factor to using this method.

Summary of the Invention

it has therefore been an objective of this invention to provide a

improved apparatus and method for producing a stress free sheet o

dough for use with the batch dough making systems.

It has been a further objective of this invention to provide a

apparatus and method for producing a stress free sheet of dough fro the batch process which is relatively inexpensive and utilizes existin dough making equipment.

The term "stress free" is used herein to refer to dough which ha

a well developed and undamaged gluten network requiring n rehabilitative measures to regenerate damaged gluten resulting fro

excessive forces or pressures applied to the dough. Furthermore, in tha the gluten network within the dough is not damaged there is ies

moisture present with the dough. Less moisture is present because a the gluten network is damaged, water is liberated within the dough

Therefore approximately 50% less flour is required in the transportatio

and forming of the stress free dough sheet.

These objectives of the invention are attained by a system fo producing a stress free sheet of dough in which individual batches o

dough are deposited into a retention hopper. The dough mass containe

within the retention hopper is then sectioned into approximately equ

volumetric portions of dougn by a pair of oppositely rotating co-actin

cutters. The cutters include a number of blades, each of whic

cooperates with a corresponding blade on the other cutter to section of

a volume of dough from the dough mass in the hopper.

The sectioned dough portions fall by gravity from the cutters t a conveyor positioned therebeiow. Frequently, the dough is soft, highl

adhesive, and tends to adhere to the blades after it has been sectione

from the dough mass. To assist the dough portions in falling onto th

conveyor, each blade has a contoured cross-sectional profile to reduc the tendency for the αougn to adhere thereto. Additionally, the cuttin

blades are coated with a teflon layer to further assist the dough portio

in dropping onto the conveyor. Lastly, a spray jet nozzle is positione

to periodically spray a deposit of vegetable oil onto the cutting blade and thereby reduce the friction and adhesion between the blades and th dough portion.

The sectioning of the dough portions from the dough mass i

regulated so that the leading end of each dough portion is overlapped o

top of a trailing end of the previous dough portion already deposited ont

the conveyor. A photo-electric detection device is positione orthogonally with respect to the conveyor to detect the trailing end o

the previous dough portion advancing downstream on the conveyor Once the trailing end of the previous dough portion is detected, th

cutting blades are signaled to section off another dough portion whic

will be deposited onto the conveyor to overlap the trailing end of the previous dough portion.

In order to maintain the overlapping dougn portions in a

longitudinally aligned configuration on the conveyor, the conveyor is

tilted approximately ten degrees with respect to a horizontal plane so that an upstream end of the conveyor is higher than a downstream end.

With the conveyor thusiy tilted, the dough portion deposited from the

cutters is positioned approximately horizontal with its trailing end resting

on the conveyor and its leading end overlapping the previous dough

portion. A misalignment is introduced into the overlapped dough portions when they are not deposited horizontally. Therefore, the inclined conveyor allows each dough portion to drop in a generally

horizontal orientation and still overlap the previous dough portion thereby

minimizing any "kick" or misalignment when the dough portions drop onto the conveyor.

The overlapped dough portions are advanced on the conveyor to be rolled into a sheet of dough having a generally uniform height and

width. A pressing roller adjustably positioned above the upper surface

of the conveyor forms the series of overlapping dough portions into a generally uniform height sheet of dough. The pressing roller is independently driven to rotate at a speed independent from the speed of

the conveyor. When the pressing roller smooths the overlapping regions

of dough, an accumulation of dough forms on the upstream side of the pressing roller. To avoid the formation of an excessive accumulation of

dougn at the pressing roller, a second ohoto-eiectπc detection device is positioned on the upstream side of the pressing roller to detect the

magnitude of the dough accumulation. If the size of the dough

accumulation exceeds a predetermined amount, the photo-electric

detection device wiil signal the cutters to cease sectioning dough portions until the dough accumulation has resided to an acceptable level

by the rolling action of the pressing roller. Therefore, the production of

a stress free sheet of dough according to this invention includes two

separate photo-electric detection devices, each of which can independently regulate the sectioning of dougn portions.

To form the overlapping dough portions into a uniform width sheet of dough, a wedge is placed between the pressing roller and the upper

surface of the conveyor on each lateral side of the overlapped dough portions. A sloped face on the wedge narrows the dough to a

predetermined width defined by the spacing between the wedges.

Additionally, side rollers independently contour and form the side edges of the dough sheet. The side rollers can be positioned in a variety of locations at a position downstream relative of the pressing roller. A side roller is positioned for each lateral side of the dough sheet and includes a motor rotating a downwardly projecting drive shaft. A

cylinder is eccentrically secured to the drive shaft to include an offset

between the major axis of the drive shaft and the major axis of the cylinder. A sleeve is retained around the circumference of the cylinder

and is capable of friction free rotation with respect to the cylinder. The

outer circumference of the sleeve contacts the side edge of the advancing dough sheet to thereby form the lateral side edge into a more uniform configuration.

The cylinder rotates in an orbit about the eccentrically mounted

drive shaft. During the portion of the orbit proximate the side edge of the dough sheet, the sleeve contacts the side edge to thereby form it

into a consistent and uniform configuration. The sleeve rotates with the

advancing dough sheet when in contact therewith and rotates with the

orbiting cylinder when not in contact with the dough sheet.

Brief Description of the Drawinos

The objectives and advantages of the present invention will become more readily apparent from the following detailed description

taken in conjunction with the accompanying drawings in which: Fig. 1 is a side elevational view of an apparatus for producing a

stress free sheet of dough according to this invention;

Fig. 2 is a top plan view of the apparatus of Fig. 1 ;

Fig. 3 is an enlarged cross-sectional view of cutting blades sectioning a portion of dough from a dough mass in the retention hopper

of the apparatus of Fig. 1 ; and

Fig. 4 is a view similar to Fig. 3 with the cutting blades rotating

in opposite directions relative to each other; and

Fig. 5 is a side elevational view of a side pressing roller forming

the lateral edge of the dough sheet.

Detailed Description of the Invention

An apparatus 1 0 for producing a stress free continuous dough sheet of uniform width and height is shown in Fig. 1 . The apparatus 10

includes a retention hopper 1 2 containing a large dough mass 14. The

retention hopper 1 2 preferably is capable of containing approximately

1 00 gallons of dough and includes a top opening 1 6 and a bottom opening 1 8. Discrete batches (not shown) of dough are deposited into the hopper 1 2 through the top opening 1 6 and co-mingled with previous

batches of dough already in the hopper 1 2 to form the dough mass 1 4.

By gravity, the dougn mass 1 2 settles to the bottom of the hopper 1 2

toward the bottom opening 1 8.

A pair of oppositely rotating cutters 20 are positioned immediately

below the hopper 1 2 at the bottom opening 1 8. The cutters 20 are rotationally driven in opposite directions by a motor 22 geared to the cutters 20 in order to section off a portion 24 of the dough mass 14

positioned between the cutters 20. The cutters 20 are preferably driven

from the same motor 22 and are interconnected by gearing or a chain drive (not shown) in order to avoid any variation in rotational velocity

between the two cutters 20. Each cutter 20 includes three blades 26 which extend radially

outward at 60 degree intervals from a major shaft 28 of the cutter 20 as shown in Figs. 3 and 4. The cutting blades 26 are preferably about 3 feet long and are coated with a teflon layer (not shown) . The cutters

20 are aligned with respect to each other so that corresponding blades

26a on each cutter 20 are positioned on a line extending between the shafts 28 of the cutters 20 when sectioning a dough portion 24 (Fig. 3) .

As a result, when the cutters 20 are rotationally driven in opposite

directions as shown by arrows A and B, the portion 24 of the dough

mass 1 4 positioned between corresponding blades 26 on each cutter 20

is sectioned from the dough mass 1 4. With the cutters 20 of the

present invention, approximately equal volumetric dough portions 24 are

successively sectioned from the dough mass 14. The cutters 20 of this

invention are designed to section off generally equal volume dough portions, preferaoiy approximately 1 000 cubic incnes - <- 55 cubic

inches per dough portion. The weight of each dough portion is

approximately 38 to 42 pounds. However, the weight of each dough

portion 24 is dependent upon the composition and specification for the particular dough to be used in the process whereas the volume of each

portion is generally substantially constant.

After being sectioned from the dough mass 1 4, each dough

portion 24 drops by gravity from the cutters 20 to an inclined conveyor

30 positioned immediately below the cutters 20 (Fig. 1 ) . If the dough

portion 24 is especially soft and adhesive, it will tend to adhere to the blades 26 of the cutters 20 and not fall to the inclined conveyor 30.

Therefore, each cutting blade 26 has a contoured surface 32 or profile in order to assist the dough portion in separating from the surface 32 of

the cutting blade (Figs. 3 and 4) . The cross sectional profile of each cutting blade surface 32 is contoured to include a triangular

configuration in which an apex 34 of the triangle is directed downwardly

toward the conveyor belt 30. The downwardly projecting contour 32 of

the cutting blade 26 promotes the separation of the dough portion 24

from the cutting blade 26 as seen in Fig. 3. Furthermore, to enhance the

separation of the dough portion 24 from the cutting blade 26, the teflon coating on each blade reduces the friction and adhesion between the

dough portion 26 and the cutting blade 26.

Additionally, a spray jet 32 with a nozzle 38 is directed toward the

cutting blades 26 to spray a deposit vegetable oil 40 onto the surface 32

of the blades 26. The deposit of oil 40 further decreases the adhesion

and friction between the surface 32 of the cutting blades 26 and the dough portion 24 thereby aiding the separation of the dough portion 24

from the cutters 20. Preferably, the vegetable oil 40 is mixed with compressed air for atomization and sprayed onto each blade 26 on alternate revolutions of the cutter 20.

The conveyor 30 advances the dough portion 24 deposited from

the cutters 20 in a downstream direction as shown by Arrow C in Fig.

2. The dough portion 24 is deposited onto the conveyor 30 so that a

leading downstream end 42 of each dough portion 24 is overlapped on

top of a trailing upstream end 44 of a previous dough portion 24a. The conveyor 30 of the present invention is angled approximately ten

degrees with respect to a horizontal plane with the upstream end of the

conveyor positioned above the downstream end of the conveyor. The conveyor 30 is angled so that each dough portion 24 is deposited onto

the conveyor 30 and the previous dough portion 24a in a generally

horizontal or flat configuration thereby minimizing any tendency for the

dough portion 24 to be misaligned or skewed with respect to the series

of overlapped dough portions. The dough portion 24 tends to skew with

respect to the previous dough portion 24a if the leading end 42 contacts the previous dough portion 24a before the trailing end 44 contacts the

conveyor 30. The tilted conveyor 30 enables both ends 42, 44 of the dough portion 24 to contact approximately simultaneously.

The operation of the cutters 20 and the timing of the sectioning

of a dough portion 24 to enable it to overlap in the appropriate

relationship with respect to the previous dough portion 24a is accomplished by a photo-electric detection device 46 positioned

orthogonally with respect to the conveyor 30. The photo-electric detection device 46 is directed to have a field of view covering the

conveyor 30 below the cutters 20. The detection device 46 is positioned to detect the trailing end 44 of the previous dough portion

24a on the conveyor 30 as it advances in the downstream direction.

Once the detection device 46 discerns the trailing end 44 of the previous

dough portion 24a, the detection device signals 46 the cutters 20 to section off the next portion of dough 24 to be deposited onto the conveyor 30 to overlap the previous dough portion 24a. As a result, the dough portions 24 are systematically and sequentially positioned on the

conveyor 30 to serially overlap the previous dough portion 24a without the need for the involved steps of weighing and calculating the

appropriate length on the conveyor belt required for the particular dough section.

The series of overlapping dough portions are advanced on the

conveyor 30 toward a pressing roller 48 positioned above and spaced

from the upper surface of the conveyor 30. The height of the pressing roller 48 is adjustable with respect to the upper surface of the conveyor

30 permitting a range of dough sheet heights. The pressing roller 48 shapes the overlapped portions of dough into a dough sheet 50 having

a uniform height. The pressing roller 48 is rotationally driven, preferably independently from the conveyor 30 in the direction of arrow D. The

pressing roller 48 is preferably independently driven from the conveyor 30 in order to accommodate an accumulation of dough 52 which forms

on the upstream side of the pressing roller 48. The pressing roller 48

forces the accumulation of dough 52 into the dough sheet 50 formed between the pressing roller 48 and the conveyor 30 by having a higher

rotational velocity than the transiationai velocity of the conveyor 30.

The accumulation of dough 52 which forms on the upstream side of the pressing roller 48 is discerned by a second photo-electric detection

device 54 positioned above the pressing roller 48. The detection device 54 ascertains the height or magnitude of the accumulation of dough 52

entering the pressing roller 48. If the accumulation 52 exceeds a predetermined level, the detection device 54 signals the cutters 20 to

cease sectioning dough portions 24 until the pressing roller 48 has reduced the accumulation of dough 52 by processing it into the dough

sheet 50. The photo-electric detection devices 46. 54 of this invention are preferably standard, off-the-shelf hardware requiring no specialized

modifications for this application.

Once the accumulation of dough 52 subsides below a

predetermined maximum level, the detection device 54 signals the cutters 20 to resume the sectioning of dough portions 24. Therefore, the cutters 20 of this invention continue to section dough portions 24

provided that the signals from both detection devices 46, 54 are positive

thereby indicating that the trailing end 42 of the previous dough portion 24a has been detected and that the accumulation of dough 52 at the

upstream side of the pressing roller 48 is below a predetermined magnitude.

The width of the dough sheet 50 is uniformly shaped with a pair

of guide wedges 56 positioned on the upstream side of the pressing roller 48 between the pressing roller 48 and the conveyor 30 as shown

in Fig. 2. A guide wedge 56 is positioned on each lateral side of the

overlapped dough portions and includes a sloped face 58 to thereby narrow and form the overlapping dough portions between the guide

wedges 56 into a uniform width dough sheet 50. Once the dough sheet 50 is formed to a uniform height and width,

it is transferred from the conveyor 30 to a second conveyor 60 for transfer to the appropriate cutting and shaping stations (not shown) as

required depending on the particular dough product being produced. As

a part of the shaping and processing of the dough sheet 50, side

pressing rollers 62 can be used to refine and contour the configuration

of the side edges of the dough sheet 50 and to further reduce the dough

sheet width. The side pressing rollers 62 are positioned on each lateral

side edge of the dough sheet 50 and include a motor and a rotational

drive snaft 66 projecting downwardly from the motor 64 (Fig. 5) . The rotating drive shaft 66 is eccentrically mounted within a cylinder 68 with

approximately a 0.8 inch offset between major axes of the cylinder 68

and the drive shaft 66. The motor 64 rotates the cylinder 68 in an orbit

about the drive shaft 66. A sleeve 70 is retained around the outer circumterence of the cylinder 68. The sleeve 70 is preferably constructed of polyvinylchloπde (PVC) and the cylinder 68 from a UHMW polyethylene in order to create minimal friction between the sleeve 70 and the cylinder 68 thereby allowing the sleeve 70 to rotate freely with

respect to the cylinder 68. A mounting brace 72 secures the side roller 62 to a conveyor table 74. The mounting brace 72 includes a handle 76 for releasing the side roller 62 and pivoting the side roller 62 about a link

arm 78 and away from the dough sheet 50 for maintenance and other

required operations.

The sleeve 70 around the cylinder 68 contacts the side edge of the dough sheet 50 moving preferably a maximum of ten feet per minute

on the conveyor 30 in the direction of Arrow E (Fig. 2) . The motor 64

preferably rotates the drive shaft 66 and the cylinder 68 approximately 1 30 revolutions per minute in the direction of Arrow F. As the dough sheet 50 advances past the side roller 62, the sleeve 70 contacts the

side edge of the dough sheet 50 when the orbit of the cylinder 68 approaches the dough sheet 50 to thereby contour and reform the dough

sheet 50 into a uniform width. The interaction between the sleeve 70

and the cylinder 68 has minimal friction thereby permitting the sleeve 70

to rotate relative to the cylinder 68 when in contact with the advancing dough sheet 50. However, the sleeve 70 rotates with the cylinder 68

in the orbit about the drive shaft 66 when it is not in contact with the

advancing dough sheet 50. As a result, the side pressing rollers 62

reform the side edges of the advancing dough sheet 50 without

imparting excessive stress or gluten damaging pressures thereto. It will

be appreciated by one of ordinary skill in the art that the side pressing rollers 62 of this invention can be used either in conjunction with or

independent from the present invention apparatus 10 for producing the stress free dough sheet.

From the above disclosure of the general principles of the present invention and the preceding detailed description of the preferred

embodiment, those skilled in the art will readily comprehend the various

modifications to which the present invention is susceptible. Therefore,

we desire to be limited only by the scope of the following claims and

equivalents thereof.

We claim: