IE20040222U1 - A process for handling meat carcasses - Google Patents

Abstract

ABSTRACT A process for removing meat from a beef carcass portion comprising the steps of providing a mechanical actuator which is driven by an electrical motor, setting a force to be applied by the actuator and the speed of the actuator, presenting a hung carcass portion of beef to the actuator, holding one of a bone to be removed or meat substantially stationary with an anchor and operating the actuator to move the meat away from the bone with the preset speed and force, cutting the meat away from the bone as the actuator pushes the meat away from the bone; and stopping the actuator if a set force threshold is exceeded. The process involves setting the direction of travel of the actuator and the distance to be traversed by the actuator. Either the bone is anchored and meat moved away from the bone by the actuator, or the meat is anchored and the bone is moved away form the meat by the actuator.

Description

The invention relates to a method of and an apparatus for handling meat carcasses using machines to assist operator deboning.

There are several types of boning machines that can be used to assist an operator in removing meat from a bone in an in—line carcass processing system. Such known systems however are generally pneumatic or hydraulic which facilitate only a limited range of movements. Such known systems are therefore generally inflexible. They are also in some cases unreliable and require regular maintenance with consequent down time and loss of production.

There is therefore a need for an improved method and apparatus which will address at least some of these issues.

Statements of Invention According to the invention there is provided a process for removing meat from a beef carcass portion comprising the steps of:~ providing a mechanical actuator which is driven by an electrical motor; setting a force to be applied by the actuator and the speed of the actuator; presenting a hung carcass portion of beef to the actuator; holding one of a bone to be removed or meat substantially stationary with an . anchor; operating the actuator to move the meat away from the bone with the preset speed and force; cutting the meat away from the bone as the actuator pushes the meat away from the bone; and stopping the actuator if a set force threshold is exceeded.

In one embodiment the process comprises the step of: setting the direction of travel of the actuator and the distance to be traversed by the actuator.

In another embodiment a bone is anchored and meat is moved away from the bone by the actuator.

In a further embodiment meat is anchored and the bone is moved away from the meat by the actuator.

In one embodiment the process is carried out at a first deboning station, and after removal of the bone at the first deboning station, the carcass portion is delivered to a second deboning station at which the process is repeated to remove a further bone from the carcass portion.

In another embodiment at the first deboning station, a bone is anchored and meat is moved away from the bone by the actuator.

In a further embodiment at the second deboning station, meat is anchored and a bone is moved away from the meat by the actuator. aEo4o22g In one embodiment at the second deboning station the process includes the steps of: mounting the carcass portion on a drop rail; lowering the drop rail; engaging the actuator against the bone at a preset speed and force to separate the meat from the bone; cutting the meat away from the bone as the actuator moves the bone away from the meat; at a predetermined position along the stoke of the actuator, raising the drop rail to present the bone meat interface to an operator to continue cutting; and stopping the actuator if a set force threshold is exceeded.

In one embodiment the carcass portion may be a carcass side or a quarter. The carcass portion may be a forequarter or a hindquarter.

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. 1 is a perspective view of a deboning machine according to the invention; lE040222 Fig. 2 is a perspective view of the machine with some parts removed for clarity; Fig. 3 is a perspective view of a screw, ball nut and associated carriage of the machine with the carriage in a start position; Fig. 4 is an enlarged view illustrating the connection between the ball screw, ball nut and carriage of Fig. 3; Fig. 5 is a perspective view of the ball screw, ball nut and carriage with the carriage in a mid position; Fig. 6 is a perspective view of the ball screw, ball nut and carriage with the carriage just past the mid position; Fig. 7 is a perspective view of the ball screw, ball nut and carriage with the carriage in a home position; Fig. 8 is a perspective view of the ball screw, ball nut and carriage with the carriage being driven towards the start position; Figs. 9(a) to 9(d) are perspective views of the machine of Figs. 1 and 2 in different positions of use; Fig. 10 is a perspective view of another deboning machine according to the invention; Fig. 11 is a perspective view of the machine of Fig. 10 with some parts removed for clarity; lE940222 Figs. 12(a) to 12(d) are perspective views of the machine of Figs. 10 and 11 in different positions; Fig. 13 is a schematic view of a control system of the machine; and Fig. 14 is a graph of typical force applied over the length/distance travelled.

Detailed Description Bone in hindquarters or forequarters of beef are guided through the system on rails (either flat bar or twin rail types) which can be powered (continuous or stop—start) or gravity fed. The meat first enters a preparation station where it is rested on a cradle for the quarter along with a retractable extension cradle for presenting the striploin region of the meat in the best orientation for butchery. Both the main cradle and the extension cradle can be retracted by pneumatic actuator to allow meat flow into and out of the station. Initial meat butchery occurs at the preparation station which is required so as to provided access to the bones at subsequent stations, e.g. drop hindquarter flank, remove fillet (psoas major), clear brisket patch, remove oyster steak to clear obturator foramen and the like. When such meat has been removed, an operator scribes the quarter with a disc saw. Scribing involves cutting through bones of two adjacent primal cuts (e.g. between striploin and flank) or where it assists the removal of the vertebral column by severing the column from the rib cage.

In general, butchered and scribed quarters enter a first deboning station 100 according to the invention as illustrated in Figs. 1 and 2 and Figs. 9(a) to 9(d). At this point, meat and bone are separated using a horizontally mounted activating means provided by an actuating arm in the form of a puller device 20. Bone(s) 180 to be removed (e.g. Ileum/vertebral column or rib cage/sternum) are held static on an IEO/+0222 anchor 181 while the meat is pushed away from the bone 180 with a pre—determined speed and force. As the puller 20 moves forward, the boner clears meat from the bones 180 in an ergonomic fashion. If a given force threshold is exceeded (due to meat not being cleared from the bones) the puller 20 stops so as not to tear the meat.

The speed, threshold force, direction of travel and position from start point can be set for one or more points along the entire length of stroke. These settings can be adjusted for different categories or raw material (e.g. hindquarters, forequarters, cows, steers, heifers, young bulls, stock bulls). Upon completion of a stroke. the puller unit 20 returns to the start position at a higher speed so as to minimise the cycle time. The stroke length is adjustable in the range 0 to 3900 mm.

After the first deboning station 100, semi—boneless quarters enter another station where meat surrounding one half of both leg bones is cleared away to facilitate the second pull at a second deboning station.

Quarters are transferred to the second deboning station 110 as illustrated in Figs. 10 and 11 and Figs. 12(a) to l2(d). A chain 83 on a roller trolley 88 is threaded through the heel of the quarter so that it is suspended from the roller when an Achilles tendon is severed. This allows the meat around the upper leg bone to be cleared away before entering the puller set up. The meat is pulled along the carcass rail into the puller arrangement which consists of an actuating means provided by an actuating arm in the form of a puller 20 and drop rail 60. The meat enters the drop rail 60 which contains a roller trolley 61. The rail 60 is lowered and a hook 65 of the roller is inserted into the meat 66. The puller arm 20 is swung into the push position and the puller 20 is activated. The arm 20 pushes against a hook 85 of a roller 88 which pushes the chain 83 engaging the bone so helping to clear meat from the lower leg bone. At a pre—determined position along the puller stroke the drop rail 60 lifts up to present the bone-meat interface at a more ergonomic position to the operator. The pulling motion continues until the meat is separated from the bone at which point it rolls freely under gravity to a final station. The bone is removed from the chain 83, the pusher arm 20 returns to the start position and the cycle starts again. Puller stroke length is adjustable in the range 0 to 3300mm.

At a final station, the boneless quarter is butchered (on line or on a table worktop) into primal cuts and placed onto meat conveyors for subsequent trimming.

Each of the deboning machines 100, 110 used in the invention are of generally the same construction. The electromechanical means (which will be described in more detail below) used to move the actuator arm 20 is the same. At the first deboning station the bone is anchored and meat is pushed away from the bone. At the second deboning station the meat is anchored and bone is pushed away from the meat. The principles of operation however are substantially the same.

The boning machines used in the process of the invention will now be described in detail. Referring to the drawings each boning machine consists of a 24mm dia x 25mm pitch lead-screw 10 and a ball—nut 11 with length of 3329mm for the first boning station 100 and a length of 3929mm for the second boning station 110. The lead screw 10 is supported by two flanged bearings 12 at either end.

The ball nut 11 is fixed to a carriage 15 rolling on 70mm dia delron plastic wheels 16 to give torsional rigidity in all planes.

The ball screw 10 is mounted in two delron support blocks 18 to prevent lead screw sag. The support blocks 18 are supported on shoulders (not shown) in a housing 25.

An L—shaped stainless steel push arm 20 is fixed to the carriage 15. The arm 20 contacts the meat/bones and transfers the pushing force to the quarters. The arm 20 is adjustable in the vertical direction using adjustable clamps to cope with different quarter sizes. A horizontal member 20A of the arm is also rotatable and fitted with a locking cam arrangement 22 so that it can be introduced behind the quarter at the IEO-40222 start of the stroke and then locked in position before activating the forward movement.

The housing 25 is a stainless steel profiled housing which encloses the lead—screw- nut—carriage—motor assembly. The housing 25 comprises two end plates 26 which attach to the main frame of the housing. The housing 25 is profiled or has two internal box section runners 30 which act as a track for the carriage 15 to run along.

A base opening 31 of the housing 25 is enclosed with a seal comprising flexible plastic sheets 35 to prevent the ingress of moisture and debris while allowing a lower portion 15A of the carriage 15 to protrude.

A 0.75kW, 3ph, 6—pole AC motor 40 fitted with a forced air-cooling fan 41 is used to actuate the lead—screw assembly. The motor provides a maximum torque of about Newton—metres and maximum lead—screw speed of about 380mm/sec.

The motor provides a 1000 pulses per revolution (ppr). A rotary shaft encoder 50 is attached to the motor 40 which equates linear motion of the pusher arm 20 with rotational motion of the lead—screw shaft 10 and feeds this signal to a central control system 60.

The second deboning machine 110 only also has a pneumatically operated drop rail assembly 60 with a one way gate system 63 to allow rollers 61 to enter but not leave the drop rail 60 when it lowers.

The power and control system comprises a power circuit having a 380V, 50Hz, 3ph power supply with an isolator, a circuit breaker and a power train to supply a vector drive 70, motor 40 and cooling fan 41. A 24V transformer is used to supply the control circuit. The control circuit (Figure 13) comprises a 24V DC circuit to control motor encoder feedback 75 (arm position), emergency stops, start/stop switches, home/away limits, program selector switch 77, cooling fan overload and output to a (E04022; pneumatic cylinder solenoid valve 78 for the drop rail 60. The vector drive 70 controls torque and speed by monitoring current and frequency outputs from the main AC power circuit.

The sequence of control will be described with reference to Fig. 13. The vector drive 70 is pre-programmed with a given force—speed-position profile for a given type of beef quarter. This profile sets out the required current and frequency parameters to be delivered by the drive during the actuator arm 20 motion between two defined points (defined in relation to the fixed home position of the arm 20). There can be a number of changes (normally two or three) in torque/speed as the actuator arm 20 moves forward and backward.

For the actuator arm 20 of the second deboning station 110, there is also a defined distance from home position where the drop rail 60 is raised.

A diagrammatic illustration of a typical force versus distance profile is given in Fig. 14. A typical sequence of control is as follows. An operator selects given program using selector switch 77. This activates a give profile stored in the vector drive 70.

For the actuator arm 20 only of the second deboning station 110, the operator activates a switch to lower the drop rail 60 into position to accept meat. The start switch is activated by the operator. The motor 40 and cooling fan 41 are activated and the arm 20 moves forward at defined speed (V1) and torque (T 1). The position of the arm 20 is continuously monitored by the encoder 50. Torque feedback is monitored by the vector drive 70 and the arm 20 stops if resistance of meat exceeds a pre—set torque.

In the case only of the actuator arm 20 of the second deboning station 110 after a pre—set travel distance L2 (as counted by number of pulses from encoder 50). the vector drive 70 sends an output signal to the solenoid valve 78 which raises drop rail lE0402 After a set length of travel (Ll), the vector drive 70 may change parameters to a lower torque (T2) for meat that is more easily detached from certain bones. When a minimum torque level (T3) is measured which is set to signify the final release of meat from the bones, the actuator arm 20 stops for a set period (the “return delay") before reversing direction and returning to the home position at a torque (T4) and at a rapid speed (V2).

The sequence of operation of the first deboning station 100 is as follows. The meat is presented to the pulling operation hanging from a hook 91 on the rail 92. The butcher clears some meat away from the bone 180 to provide an access gap into which a scissor action clamp 181 is inserted. This clamp 181 encloses the bone 180 and is anchored to an adjacent steel drop (Fig. 9(a)). The pusher arm 20 is rotated and locked so that it is able to move the meat portion forward when it is activated (Fig. 9(b)). The arm 20 is activated via a pull cord and the system moves the arm 20 at a defined speed, direction and force. This movement pushes the carcass portion away from the stationary bone 180. The butcher clears the meat from the bone 180 as the sequence progresses (Fig. 9(c)). If the meat is not cleared from the bone 180 the movement of the arm 20 stops. When the meat is cleared, it moves forward again. When the machine reaches its predetermined stroke length, the arm 20 returns to its start position (Fig. 9(d)) for the cycle to repeat.

The sequence of operation of the second deboning station 110 is as follows. In the first step (Fig. 12(a)) the meat is presented to the bone pulling operation hanging from a hook on a rail. A chain 83 is threaded between the bone and tendon. This chain 83 is used to hold the bone to an additional hook 85. The tendon is then cut at 89 (Fig. l2(b)). This leaves the meat supported by the bone via the chain 83 on the hook 85. The rail 60 then drops down to allow another hook to be connected to the meat at an ergonomic height. A gate system 63 (Fig. 12(c))on the drop rail prevents the hook from rolling off. The bone pulling machine then moves the actuator arm lEO402 , which in turn forces the bone out of the meat (Fig. 12(d)). At a predetermined stroke, the drop rail 60 rises, this assists the pulling. At the end of the stroke, the meat less bone is left hanging on the final hook.

It will be appreciated that the invention may be applied to any beef carcass portion such as a side or quarter.

The deboning machine of the invention improves the yield of meat from an animal carcass by aligning meat, bones and operator in optimum relationship to each other and determining the correct force, speed and position to pull meat or bone from each other It reduces repetitive strain on operator muscles and reduces force required to clear meat from bones. The machine also improves operator productivity by eliminating wasteful movements.

The system separates de—boning from trimming which provides wasteful movements and improves meat hygiene as fewer bones are trimmed on worktops.

The system is flexible, compact and reliable using controllable electromechanical devices as opposed to pneumatic or hydraulic systems which tend to be less reliable, more maintenance intensive and less flexible.

The system uses a programmable vector drive so that many force—fed position combinations can be set up for many different types of carcass. The system eliminates the need for position limit switches along the length of travel of the puller which improves the system hygiene and reliability.

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

Claims (2)

Claim

1. A process for removing meat from a beef carcass portion comprising the steps of: providing a mechanical actuator which is driven by an electrical motor; setting a force to be applied by the actuator and the speed of the actuator; presenting a hung carcass portion of beef to the actuator; holding one of a bone to be removed or meat substantially stationary with an anchor; operating the actuator to move the meat away from the bone with the preset speed and force; cutting the meat away from the bone as the actuator pushes the meat away from the bone; and stopping the actuator if a set force threshold is exceeded.

2. A process as claimed in claim 1 including the step of setting the direction of travel of the actuator and the distance to be traversed by the actuator, and wherein a bone may be anchored and meat may be moved away from the u-30402 bone by the actuator, or, wherein meat may be anchored and the bone may be moved away from the meat by the actuator. A process as claimed in claims 1 or 2 wherein the process is carried out at a first deboning station, and after removal of the bone at the first deboning station, the carcass portion is delivered to a second deboning station at which the process is repeated to remove a further bone from the carcass portion, and, wherein at the first deboning station, a bone is anchored and meat moved away from the bone by the actuator, or, wherein at the second deboning station, meat is anchored and a bone moved away from the meat by the A process as claimed in claim 3 wherein at the second deboning station the process includes the steps of: mounting the carcass portion on a drop rail; lowering the drop rail; engaging the actuator against the bone at a preset speed and force to separate the meat from the bone; cutting the meat away from the bone as the actuator moves the bone away from the meat; at a predetermined position along the stoke of the actuator, raising the drop rail to present the bone meat interface to an operator to continue cutting; and stopping the actuator if a set force threshold is exceeded. Meat when deboned by a process as claimed in any preceding claim.