ARRANGEMENT AND PLANT FOR FLUID JET CUTTING OF FOOD PRODUCTS

Abstract: An arrangement for fluid jet cutting, especially for food products, comprises a nozzle (6) which is movable on a frame (3, 7). The arrangement includes an angled pipe (5), one end of which is fixedly connected to and in fluid communication with one end of the shaft (4), which is hollow, of a reversible rotary motor (3), the other end of the shaft (4) being connected by means of a rotary coupling (5b) to a conduit (5a) for cutting fluid, and the other end of the pipe (5) being connected to said nozzle (6). A plant for fluid jet cutting, especially for food products comprises a belt conveyor (1) for carrying said products, a device (8) for analysing quality and/or quantity characteristics of the products to be cut, and a device (9) for controlling the operation of the fluid jet arrangement (2) for cutting the products on the conveyor (1) in response to commands from the analysing device.

Description: ARRANGEMENT AND PLANT FOR FLUID JET CUTTING OF FOOD PRODUCTS The present invention relates to a plant for fluid jet cutting of food products, comprising a belt conveyor for carrying the products, at least one arrangement com¬ prising a nozzle which is movable on a frame for producing a fluid jet, a device for analysing quality and/or quanti¬ ty characteristics of the products to be cut, and a device for controlling the operation of the fluid jet arrangement for cutting the products on the conveyor in response to commands from the analysing device. The invention also relates to an arrangement for fluid jet cutting- Such an arrangement and such a plant are disclosed in US-4,962,568. One drawback of this prior-art arrangement and plant is associated with the fluid jet cutting assembly. This comprises a rail which extends transverse to the direction of travel of the conveyor, being a conveyor belt, and on which runs a carriage provided with a spray nozzle. The spray nozzle projects from a slot provided in a housing for the assembly. The carriage is driven by a piston and cylinder unit. By this arrangement, the assembly will be exposed to heavy soiling, occasioned by water rebounding from the conveyor belt and entraining particles from the products that are being cut or have been cut earlier. This soiled water penetrates through the slot of the housing, which thus has to be dismounted for cleaning the assembly. Furthermore, there is a risk of leakage from the piston cylinders which may cause soiling of the food products. US—4,847,954 discloses a fluid jet cutting arrange¬ ment having a nozzle suspended in articulated fashion from a frame disposed beside a conveyor. The conveyor moves relative to the nozzle frame, but during the cutting of a product located on the conveyor, either the conveyor or the nozzle frame appear to be stationary. US-5,133,687 discloses an automatic butchering system where the nozzle of the fluid jet cutting arrangement is suspended from a complex articulated-arm system. Moreover, the known fluid jet arrangements are quite complicated. The object of the invention is to overcome the above- mentioned problems. This object has been achieved by means of an arrange¬ ment and a plant having the features recited in the char- acterising clauses of the appended claims. Since the fluid jet arrangement is of rotational type, the housing of the arrangement can be provided with a simple lead-in opening for the spray arm, which can easily be sealed by means of a gasket. Thus, the housing need not be dismounted when the plant is to be cleaned, and the sensitive, movable components accommodated therein will remain protected and sealed in the housing during both the operating phase and the cleaning phase. The cen¬ tral bearing for mounting the fluid-jet conducting arm means that the number of parts of the fluid jet cutting arrangement that are located in the area of the plant exposed to cutting fluid can be minimised. The circular-arc movement pattern for the fluid jet nozzle enables cutting the products carried on the con- veyor, while this too is in motion, and producing cuts, almost perpendicular to the direction of movement of the conveyor, in the products thereon, which means an increase in production as compared with the prior art. This is achieved by the nozzle-carrying arm, during part of its pivotal motion over the conveyor belt, being capable of moving in the same direction as the conveyor. The circular-arc motion of the nozzle also allows the creation of such cutting patterns as a translatory move¬ ment of the conveyor belt or of the nozzle transversely of the belt does not permit. It is further evident that the invention provides an uncomplicated fluid jet cutting arrangement. It does no longer suffer from the necessity of a vast number of com¬ ponents, such as toothed belts, gears, piston and cylinder units with air/fluid supply hoses, lubricant, seals and joints. In the fluid jet cutting arrangement of the inven¬ tion, only one arm with its nozzle need be moved. Also, these components may be very lightweight, which contri¬ butes to high acceleration ability and, hence, increased production capacity. The rotary arrangement also means quicker accele¬ ration of the jet nozzle to the desired cutting places and, hence, achievement of more acute corners upon direc¬ tional changes in the cutting pattern, with a consequent reduction of product waste and an increased production rate. The invention will now be described in more detail with reference to the schematic drawings, in which Fig. 1A is a side view of a plant according to the invention; Fig. IB shows a cutting pattern obtained with the arrangement and the plant of Fig. 1, and Fig. 2 shows the plant from above. Over a belt conveyor 1 for carrying food products, in this case chicken brests, there are arranged a number (in this case four) stationary water jet assemblies 2 for cut¬ ting chicken breasts B in two trimmed segments of fillets. The water jet assemblies 2 are arranged in a row verti¬ cally above the longitudinal centre line of the belt 1 (Fig. 2). They comprise a rotary motor 3 of reversible type, whose shaft 4 is fixedly connected to an arm 5, mak¬ ing an angle with the shaft. The shaft 4 and the arm 5 consist of pipe sections serving to supply water from a source of water to a spray nozzle 6 fixed on the free end of the arm 5. The upper end of the shaft 4 is connected to a conduit 5a from the source of water by means of a rotary coupling 5b. The lower end of the shaft 4 is supported in a liquidproof stationary housing 7 for the motor 3 by means of a ball bearing (not shown). The lead-in opening for the shaft 4 in the housing 7 is sealed by means of a gasket 5c. The arrangement further comprises a device for deter¬ mining quality/quantity parameters of the chicken breast. These parameters control the operation of the water jet assemblies 2 (the motors 3 thereof) to provide the trimmed segments or fillets, via a computer. Such a device may be of the type described in US 4,962,568. It includes a video camera 8 positioned to "see" the food products on the con¬ veyor belt 1, and a light source for illuminating the food products with a light line so as to produce a shadow line on the product. The video camera 8 views this shadow line and converts shadow line information into electrical sig¬ nals representing the width, length and thickness dimen¬ sions of the product. The signals are processed in a com¬ puter 9 in accordance with a predetermined program, the computer controlling the operation of the water jet assem- blies 2 to provide cutting motions for cutting the product into segments of desired weight/volume/profile. Alternatively or as a complement to the above-men¬ tioned shadow line analysis, the technique according to US-4,631,413 (to which the applicant is a licensee) can be used for controlling the operation of the cutting jet assemblies 2 to cut the products into segments of the desired profile. This technique is based on fluorescensce analysis of food products, such as fish and meat products, for determining the content of fat, bone, cartilage and connective tissue. The cutting pattern shown in the drawing can be achieved e.g. by means of the last-mentioned technique. The back ridge a, the fat portions b and c and the car- •tilage portions d have their characteristic fluorescence which therefore is usable for controlling the operation of the fluid jet cutting assemblies to cut off these portions to obtain the desired segments e. The cutting operations may be performed as follows, reference being made to Figs 1 and 2. A chicken breast B transported on the conveyor belt 1 in the direction of the arrow A passes in turn through cutting stations I-IV, where the fluid jet cutting assemblies 2 are activated by the computer 9 to provide the cuts S1-S4 by the motors 3 swinging the arms 5 with the nozzles 6 transversely (arrow C) of the conveyor 1, and by varying the speed of the pivotal motion (the speed of the belt 1 is constant). Thus, the cut SI along one side of the back ridge a is made in station I, and the cut S2 along the other side of the back ridge a is made in station II, whereupon in sta¬ tions III and IV the cuts S3 and S4 separate the segments e from the breast pieces b-d. The nozzles 6 are fixed on the respective arms 5 at a suitable angle to obtain the desired, clean cuts through the chicken breast B.

Claims: CLAIMS 1. An arrangement for fluid jet cutting, especially for food products, comprising a nozzle (6) which is mov¬ able on a frame (3, 7), c h a r a c t e r i s e d in that it comprises an angled pipe (5), one end of which is fixedly connected to and in fluid communication with one end of the shaft (4), being hollow, of a reversible rotary motor (3), the other end of the shaft (4) being connected by means of a rotary coupling (5b) to a conduit (5a) for cutting fluid, and the other end of the pipe (5) being connected to said nozzle (6). 2. A plant for fluid jet cutting, especially for food products, comprising a belt conveyor (1) for carrying said products, at least one arrangement (2) comprising a nozzle (6) which is movable on a frame (3, 7) for producing a fluid jet, a device (8) for analysing quality and/or quan¬ tity characteristics of the products to be cut, and a device (9) for controlling the operation of the fluid jet arrangement (2) for cutting the products on the conveyor (1) in response to commands from the analysing device, c h a r a c t e r i s e d in that the fluid jet arrange¬ ment comprises an angled pipe (5), one end of which is fixedly connected to and in fluid communication with one end of the shaft (4), being hollow, of a reversible rotary motor (3), the other end of the shaft being connected by means of a rotary coupling (5b) to a conduit (5a) for cut¬ ting fluid, and the other end of said pipe (5) being con- nected to said nozzle (6).

Inventors: DALUM LEIF, NIELSEN JENS, DALUM, LEIF, NIELSEN, JENS
Applicants: DALUM LEIF, LUMETECH AS, NIELSEN JENS, LUMETECH A/S
Application year: 1993
Main classification: A22C25
IPC codes: A22C21, A22C25, B26D3, B26F3