IES20040211A2 - An apparatus for handling frozen meat patties - Google Patents

Abstract

Apparatus for handling frozen patties comprising a freezer conveyor along which rows of meat patties are led through a freezer, a transfer means comprising a transfer conveyor and a transfer plate for lifting the frozen patties off of the freezer conveyor and delivering them onto the transfer conveyor. The apparatus comprises a stacker infeed conveyor to which the patties are delivered by a transfer conveyor and an iris into which the patties are introduced form the stacker infeed conveyor. The iris is movable from a closed configuration to receive patties to an open configuration for delivery of patties form the iris. A receiver for receiving a stack of patties is provided below the iris. The apparatus also comprises a delivery means for delivering a stack of patties form the receiver to a stack takeaway conveyor.

Description

j LODGED Introduction The invention relates to a process and apparatus for preparing, handling and packaging frozen meat patties.

The handling and packaging of frozen meat patties on a factory scale is time consuming, highly labour intensive and requires a large area of factory floor for performing the various required operations.

There is a need for a process and an apparatus which will address these issues.

Statements of Invention Apparatus for handling frozen patties comprising:a freezer conveyor along which rows of meat patties are led through a freezer; a transfer means comprising a transfer conveyor and a transfer plate for lifting the frozen patties off of the freezer conveyor and delivering them onto the transfer conveyor; a stacker infeed conveyor to which the patties are delivered by the transfer conveyor; an iris into which the patties are introduced from the stacker infeed conveyor, the iris being movable from a closed configuration to receive patties to an open configuration for delivery of patties from the iris; __ ... .. --------- £0402 1 ί a receiver for receiving patties below the iris; and a delivery means for delivering a stack of patties from the receiver to a stack takeaway conveyor.

In one embodiment the transfer plate is biased into a position engaging against an upper face of the freezer conveyor for lifting the frozen patties from the freezer conveyor. The transfer plate may be spring biased into the freezer conveyor engaged position.

The apparatus preferably comprises a vibrator for vibrating the transfer plate.

In one embodiment the leading end of the stacker infeed conveyor is spaced-apart from the trailing end of the transfer conveyor to provide an exit path for undersize material from the freezer conveyor. The gap may be from about 20mm to about 40mm.

In one embodiment the transfer conveyor is a variable speed conveyor for phasing of rows of patties.

In another embodiment the stacker infeed conveyor is a variable speed conveyor for phasing of rows of patties.

In another embodiment the stacker infeed conveyor is an accelerator conveyor for speeding up and angling rows of frozen patties for optimum insertion into the stacker iris. ¢04 02 1 1 The apparatus may comprise stop means associated with the stacker infeed conveyor for engaging frozen patties to straighten staggered rows of patties prior to delivery into the iris stacker.

In one embodiment the iris stacker comprises a pair of iris plates which are movable from a closed configuration to receive a row of patties to an open configuration to present the patties to the receiver.

In another embodiment the delivery means for delivering a stack from the receiver comprises a pusher plate for sweeping across the receiver to remove the stack.

In one arrangement the stack takeaway conveyor has first and second gates having a spacing therebetween to provide a gap between pack collations. In this case the apparatus may comprise control means to close a leading gate to receive a first stack collation and to close a trailing gate to prevent entry of a second stack collation until the first stack collation has passed through the leading gate.

The apparatus may comprise a flow wrapper for wrapping a stack collation delivered by the stack takeaway conveyor. A cartoning unit for cartoning the wrapped stack collations may also be provided as may a packing unit for packing the cartons in an outer package.

Brief Description of the Drawings The invention will be more clearly understood from the following description thereof given by way of example only, in which:Fig. A is a plan view of a meat pattie former plate used in a meat pattie production process according to the invention. £04021, Fig. 1 is a perspective view of a stacker assembly of the invention; Fig. 2 is a perspective view of a transfer plate and associated conveyor part of the assembly; Fig. 3 is a perspective view of an acceleration conveyor and associated parts of the assembly; Fig. 4 is a perspective view of an escapement part of the assembly; Figs. 5(a) to 5(d) are perspective views of the transfer plate and associated conveyor illustrating a transfer sequence; Figs. 6(a) to 6(d) are perspective views of the acceleration conveyor and associated parts illustrating a stacking sequence; and Figs. 7(a) to 7(d) are perspective views of the escapement illustrating an escapement sequence.

Detailed Description The invention provides a process for preparing meat patties on a large factory scale in which blocks of frozen meat products at about -18°C are first tempered to a temperature of about -4°C over a period of at least 8 hours. The tempered blocks are loaded into a conveyor for conveying to a coarse grinder in which the blocks of meat are ground to meat pieces of a size of from 25 to 30mm. The ground pieces of meat are then conveyed to a mincer in which the meat pieces are minced to a size of from 5 to 6mm. The minced meat is then delivered into a blender in which the meat is blended with additional ingredients such as spices and flavouring. The blended «<Μ02|| minced meat is then conveyed to a former in which rows of minced meat patties are produced.

The former comprises a former plate 91 as illustrated in Fig. 1 having a plurality, in this case seven, pattie former openings 95 therein which are staggered across the width of the former plate 91. Each pattie forming opening 95 is offset with respect to an adjacent pattie forming opening 95 across the width of the plate 91. The staggering of the openings across the width of the plate is important because for a given width of former plate the number of openings is maximised and hence the production rate of patties through the former is optimised. For example, we have found that by staggering the openings in the manner illustrated production can be increased by about 16%.

The formed patties are then led through a freezer. Preferably the freezer is an impingement freezer tunnel to freeze the patties to a pattie temperature of about 18°C during a residence time in the impingement tunnel freezer of about 2 to 3 minutes. The temperature in the impingement freezer tunnel is maintained at about 46°C. The conveyor through the tunnel travels in a substantially straight line to maximise production. The staggering of the patties across the width of the conveyor as they are led through the freezer tunnel optimises residence time and freezer efficiency.

The meat patties may be subjected to further operations after the former and prior to leading through the freezer tunnel. For example, the surface of the patties may be scored, the patties may be spiced or coated or the patties may be char cooked. The frozen patties are stacked and the stacks are packaged.

The invention provides a meat pattie production process and apparatus in which the process is optimised for increased rates of production. ¢0402 1 1 In one case the patties are staggered during forming. However, the patties can simply extend in straight away. In genera, meat patties at -2°C are formed in a forming machine. Rows of formed patties enter an impingement freezer at -46°C where they are frozen to -18°C in 2 to 3 minutes depending on the patty weight and geometry.

Rows of patties 5 exit the impingement tunnel freezer along a freezer outlet conveyor 1 and are transferred onto a transfer conveyor 2 with minimal row distortion. This is difficult because the patties are often frozen to the tunnel wire mesh belt 1. To achieve transfer, a solid stainless steel vibrating transfer plate 3 is provided between the freezer outlet belt 1 and the transfer conveyor 2. The transfer plate 3 is also spring loaded so as to rest against the impingement freezer belt 1 as it turns around its drive sprocket and hence prevent any gap forming between the mesh belt 1 and the transfer plate 3. The plate 3 is located to minimise the land length of the plate 3 and avoid nose-diving of a patty beyond an angle of 22°.

Patty rows are assisted in their transfer across the transfer plate 3 by the transfer conveyor 2 which pulls patties 5 off the plate 3. The transfer conveyor 2 has a small “bull-nose” radius to facilitate a minimum gap between the plate 3 and the conveyor 2. The conveyor 2 has variable speed facility and is used to phase collations, i.e. to count a set number of patty rows and then slow down to create a gap between one collation of stacks of patties and the next.

Patty rows are then transferred by the transfer conveyor 2 onto an acceleration conveyor 10. A small gap 9 of 20-40mm is provided between the end of the transfer conveyor 2 and the accelerator conveyor 10. The gap 9 acts as a trap for extraneous meat that can be present on the freezer belt 1 and avoids this debris being stacked in error. £0402 1 The acceleration conveyor 10 has a number of functions. The conveyor 10 speeds up and angles rows of patties to the correct speed/angle for insertion into a stacker iris plate. The conveyor 10 can also be used to phase rows of patties a second time as per the transfer conveyor 2. In addition, the conveyor 10 provides length for the mounting of a stopper plate than can be used to straighten up staggered rows (if required at speeds above 130row/min). The accelerator conveyor 10 is pivoted on a pneumatic cylinder (not shown) so that the conveyor 10 can be raised and provide a stacker by-pass route for manual stacking, if required.

From the accelerator conveyor 10 patty rows enter an iris pocket having iris plates 11, 12 where they settle and come to rest. Each row is counted using a photocell as it enters. Patties come to rest between two vertical guideplates 19 - one of which is adjustable to suit different size patties.

As more patties enter the iris plate 11,12 and build up a stack, the iris plate 11, 12 opens and the collation drops onto a lifter plate 15. When the required quantity of patties enter the iris, the lifter plate 15 lowers and the stack leaves the iris. The iris plate 11, 12 closes ready to accept the first burger in the next collation.

The lifter plate 15 lowers to a fixed position and a pusher plate 16 sweeps across to remove the stack from the lifter plate 15 onto one of two takeaway conveyors 20, 21 which feed flow-wrappers respectively. It is also intended that stacks will be swept onto take-away conveyor 21 which can be used to feed the adjacent foodservice area.

To improve processing speed the iris plates 11, 12 may remain closed to allow part of a stack such as three patties to build up on the plates 11, 12. The iris plates 11, 12 are then opened allowing the partial stack to pass onto the receiver lifter plate 15. With the iris plates 11, 12 open further patties are built up on the stacks until the required stack number is reached. At this stage the iris plates 11, 12 can be closed ¢0402 1 ί ready to receive the first patties of the next stacks whilst allowing the handling of the first stacks on the lifter plate to be continued as described above.

Stacks 29 enter an escapement device 30 which consists of two parallel guides 31, 32 in the direction of stack movement followed by first and second gate escapements 37, 38. The gap between the guides 31, 32 is adjustable to suit stack width and the gaps between the gate escapements 37, 38 are set to provide a division between each pack collation, such as two stacks or three stacks.

A photocell picks the oncoming arrival of a pusher peg on the flow-wrapper. This triggers the release of the escapement 38 and the stack 29 moves out of the escapement into the wrapper. After a set time delay, escapement 37 opens and the next collation enters the escapement 38. This time delay creates a gap between collations so that a second photocell can detect the arrival of collation and close escapement 38 before it arrives. A third photocell detects the successful arrival of the next collation and closes the gates of escapement 37.

In more detail, the transfer conveyor 2 is a fabric/PVC belt conveyor with variable speed AC motor drive. Drive and idle rollers are tapered to ensure consistent tracking and also have screw adjustable alignment. The vibrating transfer plate 3 is stainless steel with smooth milled surface to minimise friction.

The iris, lifter and pusher elements are all servo controlled to maximise control of speed, position and force for various products. Actuation is achieved by timing belt (iris and pusher) or ball/lead-screw (lifter). Iris guides are manually actuated by lead-screw.

The take-away conveyors 20, 21 are modular belting, stainless steel frame with AC motor on inverter speed control. £0402 f 1 The escapements are of fabric/PVC split belt conveyor to facilitate loading between flow-wrapper pegs powered by AC motor with speed control. The gates are actuated by two pneumatic cylinders per gate. Guides are manually adjusted by lead-screw.

The operations are controlled via a PLC unit with photocell, servo drive and limit switch inputs.

Referring in particular to Figs. 5(a) to 5(d) in step one (Fig. 5(a)) of the transfer sequence the four leading patties 5(a) from staggered rows are transferred across the transfer plate 3 without distortion. In step two (Fig. 5(b)) the three trailing patties 5b from the same staggered row crosses the vibrating transfer plate 3, without restriction, while the four leading patties 5a are slowed down by transfer conveyor 2. In step three (Fig. 5(c)) the three leading patties 5a meet accelerator conveyor 10, while catching up with the four leading patties from same row. In step four (Fig. 5(d)) the patties are organised into an almost straight row ready for stacking.

Referring in particular to Figs. 6(a) to 6(d) in a first stage (Fig. 6(a)) of the stacking sequence patties are accelerated by the accelerator conveyor 10 and land on the iris plates 11,12. In the second step (Fig. 6(b)) a second row of patties lands on first row (stack height depends on product). The lifter plates 15 rise up to meet stacks. In a third step (Fig. 6(c)) the iris plates 11, 12 open to allow stacks onto the lifter plate 15. At this point the accelerator belt 20 slows down, thus phasing a gap in the oncoming rows. On certain products the transfer conveyor 2 also phases product. In a fourth step (Fig. 6(d)) as the lifter plate 15 returns to the down position the iris plates 11, 12 closes. Pusher plate 16 wipes stacks off the lifter plate 15, onto the take-away conveyor. The first row of the second stack lands on the iris plates 11,12. This sequence continues for the take-away conveyor.

Referring particularly to Figs. 7(a) to 7(d) in a first step of the escapement sequence a flow wrapper pusher is detected, gate 38 opens, split belts release first collation 1^04 0 2 1 1 into wrapper. In a second step (Fig. 7(b)), after time delay, gate 37 opens, second collation moves into position. In a third step (Fig. 7(c)) an oncoming second collation is detected, and the gate 38 closes. In a final step (Fig. 7(d)) final arrival of the second collation is detected, and the second gate 37 closes. The sequence repeats from the first step.

The system substantially reduces the labour content to stack, transport and package frozen meat patties. The system also improves the consistency of patty stacks which will increase the uptime of subsequent packaging machines from 95% to 98% with a consequent reduction in labour, overhead and material unit costs. In addition, the system reduces repetitive strain on operator muscles as they stack and orientate patties at high speed. The system also reduces the amount of human contact with the meat product and hence reduces the risk of contamination with pathogenic bacteria. Further the system provides an automatic history of machine uptime and reasons for downtime to assist management plans for improved efficiency. The system is flexible for all the variations of product and collation and requires no change-parts. The system is compact and does not require major structural changes to the existing buildings or production line. Further, the system is very high speed and can stack at speeds of 130 rows per minute.

The invention is not limited to the embodiments hereinbefore described which may be varied in detail.

Claims (5)

Claims

1. Apparatus for handling frozen patties comprising ία freezer conveyor along which rows of meat patties are led through a freezer; a transfer means comprising a transfer conveyor and a transfer plate for lifting the frozen patties off of the freezer conveyor and delivering them onto the transfer conveyor; a stacker infeed conveyor to which the patties are delivered by the transfer conveyor; an iris into which the patties are introduced from the stacker infeed conveyor, the iris being movable from a closed configuration to receive patties to an open configuration for delivery of patties from the iris; a receiver for receiving a stack of patties below the iris; and a delivery means for delivering a stack of patties from the receiver to a stack takeaway conveyor.

2. Apparatus as claimed in claim 1 wherein the transfer plate is biased into a position engaging against an upper face of the freezer conveyor for lifting the frozen patties from the freezer conveyor, the transfer plate may be spring biased into the freezer conveyor engaged position. »f0 4 Ο 2 1 ι

3. Apparatus as claimed in any preceding claim wherein the leading end of the stacker infeed conveyor is spaced-apart from the trailing end of the transfer conveyor to provide an exit path for undersize material from the freezer conveyor, the gap may be from about 20mm to about 40mm, the transfer 5 conveyor may be a variable speed conveyor for phasing of rows of patties.

4. Apparatus as claimed in any preceding claim wherein the stacker infeed conveyor is a variable speed conveyor for phasing of rows of patties, the stacker infeed conveyor is an accelerator conveyor for speeding up and 10 angling rows of frozen patties for optimum insertion into the stacker iris.

5. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.