Nozzle and valve assembly

Abstract: A nozzle and valve assembly (100) comprises a cylinder (102) having an open end and a piston (104) having a conical deflecting surface (140) on its lower end. A first supply pipe (114) is connected to the interior of cylinder (102) through an aperture (110) in its wall. A second supply pipe (120) is connected through a bore (119) formed in the wall of the cylinder (102) to an inwardly directed orifice (130) positioned at the bottom of the cylinder (102). In use, with the piston (104) in a raised position, a solid product is supplied through the first supply pipe (114) and discharged through the open end of the cylinder (102) into a container. The piston (104) is lowered, thereby closing off the aperture (110) in its wall and hence the first supply pipe (114), until its lower end is level with the inwardly directed orifice (130). Liquid is then supplied through the second supply pipe (120). The liquid washes away any solid on the conical deflecting surface (140) and is formed by the conical deflecting surface into a smooth slow flowing column of liquid.

Description: This invention relates to a nozzle and valve assembly for supplying a product to each one of a series of containers. In the packaging industry, there is a general requirement for a device which is capable of supplying a predetermined amount of a product to each one of a series of containers. The product may be a mixture of a particulate solid product and a liquid. After a predetermined amount of product has been supplied to a container, there is the requirement for the device to provide a clean cut-off of the supply of the product without supplying any extra product until supply is recommenced for supplying the next container. GB-A-2089440 discloses a pump for metering two fluids, particularly a relatively thick fluid, such as a suspension of solid particles in a liquid, with an homogeneous liquid. The pump comprises a first cylinder containing a floating, solid, first piston and having an inlet conduit and an outlet conduit, a second piston in a second cylinder and for closing the communication between the first cylinder and its inlet conduit and between the first cylinder and its outlet conduit, alternately, the first piston drawing in the thick fluid from the inlet conduit and discharging it into the outlet conduit, and a third cylinder having a piston for drawing in the thin fluid from a second inlet conduit which piston has at least one port provided with one or more valves through which the thin fluid can flow to occupy the space between the first and third pistons where it can transmit the motion of the third piston to the first piston, and a by-pass for conveying thin fluid from the space between the pistons to the outlet conduit. The bypass serves to feed thin fluid to an inwardly directed nozzle in the lower end of the outlet conduit to inject thin fluid into the discharge section to wash away traces of the thick fluid from the lower end of the second piston and from the internal surface of the discharge section, which converges downwardly from just above the level of the nozzle. GB-A-1484763 discloses a filling head comprising a vertical, cylindrical casing having an axial outlet tube at its lower end for viscous product, such as tomato paste. An inlet for the product is spaced above the outlet at one side of the outlet tube and communicates with a product chamber between the inlet and the outlet. The outlet tube is adapted to fit into the neck of a container during filling. A rod is reciprocable co-axially of the casing and has a valve head adapted to move downwards into and seal the outlet tube. To avoid "coning" of viscous product, a short burst or premeasured quantity of atmosphere under pressure, such as air, sterile inert gas, nitrogen or steam is fed through an axial conduit in the rod at the end of a filling cycle to cause residual product in the outlet tube to be pushed down into the neck of the container to prevent coning of the product. It is an object of this invention to provide a nozzle for use in supplying predetermined amounts of a product and which meets the requirements set out above. According to one aspect of the present invention, there is provided a nozzle and valve assembly comprising a cylinder having an open end, a first inlet leading into the interior of the cylinder, a second inlet, a piston having a free end and mounted for reciprocating movement in the cylinder at least between a first position and a second position, the piston permitting communication between the first inlet and the open end of the cylinder when the piston is in the first position, said free end of the piston moving past the first inlet as the piston moves from the first position to the second position so as to prevent communication between the first inlet and said open end of the cylinder, a fluid deflecting surface formed on said free end of the piston, means on the cylinder in the region of fluid deflecting surface when the piston is in the second position, and means for connecting the second inlet with the fluid directing means, characterised in that said fluid deflecting surface is conical and concave. According to another aspect of the present invention, there is provided a method of supplying a particulate product and a liquid to a container, said method comprising the steps of: a) providing a nozzle and valve assembly comprising a cylinder having an open end, a first inlet leading into the interior of the cylinder, a second inlet, a piston having a free end and mounted for reciprocating movement in the cylinder at least between a first position and a second position, the piston permitting communication between the first inlet and the open end of the cylinder when the piston is in the first position, said free end of the piston moving past the first inlet as the piston moves from the first position to the second position so as to prevent communication between the first inlet and said open end of the cylinder, a liquid deflecting surface formed on said free end of the piston, means on the cylinder in the region of said open end for directing liquid inwardly and on to the liquid deflecting surface when the piston is in the second position, and means for connecting the second inlet with the liquid directing means; b) positioning a container beneath the open end of the cylinder; c) supplying a particulate product to the first inlet when the piston is in the first position; d) moving the piston from the first position to the second position after a desired amount of the particulate product has been supplied to the container; and e) supplying the liquid to the second inlet with the piston still in the second position, characterised by supplying a liquid to the second inlet when the piston is in the first position. In order that the invention may be clearly understood and readily carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a longitudinal sectional view of a nozzle and valve assembly embodying this invention and showing the assembly in a state for supplying a solid product; Figure 2 is a longitudinal sectional view of the nozzle and valve assembly of Figure 1 showing the assembly in a state for supplying a liquid product; Figure 3 is a longitudinal sectional view of the nozzle and valve assembly of Figure 1 showing the assembly in a state in which it may be sterilized; and Figure 4 is a block diagram of the nozzle and valve assembly of Figure 1 connected to a supply pipe for a solid product and a metering valve for a liquid product. Referring now to Figures 1 to 3, there is shown a nozzle and valve assembly 100 for supplying a predetermined amount of a particulate solid product followed by a predetermined amount of a liquid product to each one of a series of containers. The containers may be, for example, metal cans, plastic pots, paperboard cartons or glass jars. The particulate solid product may be, for example, a food product such as, suitably sized, whole sliced or diced vegetables and pieces of meat in the form of a stew, or various fruits in a compote. In this case, the liquid product will be a liquid which is suitable for combining with the solid food product. The particulate solid product may also be a non-food product. The nozzle and valve assembly 100 may also be used to supply a particulate solid product on its own. Where the nozzle and valve assembly 100 is used to supply a food product, the food product may be supplied to the containers after sterilization. Alternatively, the product may be supplied before sterilization and, in this case, the product may then be sterilized in the containers after they have been sealed. The nozzle and valve assembly 100 includes a cylinder 102 and a piston 104 mounted for reciprocating movement in cylinder 102. The cylinder 102 has a cylindrical bore 106 and the lower end of cylinder 102 is open. An aperture 110 is formed in the wall of cylinder 102 towards its lower end. The opening 110 serves as a first inlet and this inlet receives, in use, a solid particulate product. On the outside of cylinder 102, there is provided a coupling member 112 for connecting the aperture 110 to a supply pipe 114. Above the aperture 110 and at the rear of the cylinder 102 as shown in Figure 1, a second aperture 118 is formed in the wall of cylinder 102. This aperture 118 provides a second inlet which receives a fluid in the form of a liquid product or a gas. On the outside of cylinder 102, aperture 118 is connected with a supply pipe 120. The aperture 118 is also connected to an internal bore 119 which leads from aperture 118 towards the bottom of cylinder 102. The lower end of cylinder 102 terminates with a thin walled annular section 124. The annular section 124 is enclosed within an annular end member 126. The external surface of the annular section 124 and the internal surface of the annular end member 126 together define an axially extending annular passage 128 and an inwardly directed annular orifice 130. The annular passage 128 is in communication with the bore 119. As will be explained later, the orifice 130 directs fluid inwardly. At its upper end, the cylinder 102 is closed by a cover 130 which receives a supply pipe 132. When the assembly 100 is used to supply a sterilized product, sterile air is supplied through pipe 132 so as to keep the interior of the assembly in a sterile condition. On the free end of the piston 104, there is formed a deflecting surface 140. The deflecting surface 140 is conical and concave and is symmetrical with respect to a central axis 142. The piston 104 is provided with a rack 146 which engages a semi-circular gear wheel 148 mounted on a housing 150. The gear wheel 148 is rotated by a motor or other actuator, not shown, thereby causing the piston 104 to reciprocate within cylinder 102. Beneath the rack 146, an annular seal 152 is received in a groove formed in piston 104. Referring now specifically to Figure 1, the assembly 100 is shown in a state for supplying a predetermined amount of particulate solid product to a container. In this state, the piston 104 is raised into a first position so that its free end is level with the top of aperture 110. This permits solid food product to flow from supply pipe 114 through bore 106 and to be discharged through the open end of cylinder 102. As the solid food product passes the free end of piston 104, a portion of it may adhere to this free end. As the deflecting surface 140 on the free end is conical and concave, it approximates to the form that sticky solids would naturally take up on the end of a piston. Consequently, the mass of solids which actually adhere to the free end of the piston will be minimal. After the predetermined amount of the solid product has been supplied to the container, the piston 104 descends, thereby closing off the inlet 110, until it reaches its second position as shown in Figure 2. In this second position, the free end of piston 104 is level with the bottom end of the annular section 124 of cylinder 102. When the piston 104 is in this second position, the assembly 100 is in a state for supplying liquid to the container. With the piston 104 in the position shown in Figure 2, a predetermined amount of liquid may be supplied under pressure from a metering valve through supply pipe 120. The liquid passes through the aperture 118, bore 119, annular passage 128 and orifice 130. The orifice 130 directs the liquid inwardly and onto the fluid deflecting surface 140. The deflecting surface 140 progressively deflects the liquid downwardly so as to form it into a smooth slow flowing column of liquid. Because the liquid is formed into a column in this manner, air entrainment is avoided. When a predetermined amount of liquid has been supplied, liquid is prevented from flowing through the orifice 130 by surface tension. Thus, a clean cut-off is obtained and no drips of liquid fall from the assembly 100 between containers. As the liquid passes over the fluid deflecting surface 140, it washes away any solid product which has adhered thereto. Where it is desired to supply a relatively large amount of liquid to each container, some of the liquid may be supplied while the piston 104 is in the raised position as shown in Figure 1. The assembly shown in Figures 1 to 3 is also suitable for supplying only a predetermined amount of a particulate solid product to each container and without the supply of any liquid product. Where solid product only is to be supplied, the supply pipe 120 is connected through a valve to a source of a gas. The gas may be , for example, air, steam or nitrogen. Then, when the valve 104 is in the lower position shown in Figure 2, the valve is opened for a short period with the result that the gas is directed on to the fluid deflecting surface 140 and thereby blows any solids which have adhered thereto downwards into a container. When the assembly 100 is not supplying either a particulate solid product or a liquid product, the piston 104 may be retracted slightly upwardly from the position shown in Figure 2. Figure 3 shows the position adopted by the piston 104 when it is desired to clean the assembly. In this position, the seal 152 is raised above the bottom of housing 150. In order to sterilize the assembly, a sterilizing fluid, such as steam, is supplied to the supply pipes 114, 120 and 132. As may be observed, sterilizing fluid from the supply pipe 132 can pass through the upper part of cylinder 102 and into the interior of housing 150. It can also flow past the seal 152 and the outer surface of the lower part of piston 104 so that it is discharged through the open end of cylinder 102. During cleaning, a return pipe 154 for the cleaning fluids is connected to the lower end of the cylinder 102 by a coupling member 156. During sterilisation by steam, the coupling member 156 includes a valve for containing pressure. Referring now to Figure 4, there is shown a block diagram of the assembly 100 together with a supply pipe 161 for a particulate solid product and a supply pipe 160 for a liquid product. The supply pipes 160,161 are connected through respective metering valves 162,163 to the supply pipes 120,114. In Figure 4, the assembly 100 is shown supplying products to a container 164. By way of example, the metering valves 162,163 of Figure 4 may take the form shown in published European patent application EP-A-0 280 537 or published European patent application EP-A-0 492 928 (prior art document according to Articles 54(3) and 54(4) EPC).

Claims: A nozzle and valve assembly comprising a cylinder (102) having an open end, a first inlet (110) leading into the interior of the cylinder (102), a second inlet (118), a piston (104) having a free end and mounted for reciprocating movement in the cylinder (102) at least between a first position (Figure 1) and a second position (Figure 2), the piston (104) permitting communication between the first inlet (110) and the open end of the cylinder (102) when the piston (104) is in the first position, said free end of the piston (102) moving past the first inlet (110) as the piston (104) moves from the first position to the second position so as to prevent communication between the first inlet (110) and said open end of the cylinder (102), a fluid deflecting surface (140) formed on said free end of the piston, means (130) on the cylinder (102) in the region of said open end for directing fluid inwardly and on to the fluid deflecting surface (140) when the piston (104) is in the second position, and means (119) for connecting the second inlet (118) with the fluid directing means (130), characterised in that said fluid deflecting surface (140) is conical and concave. A nozzle and valve assembly as claimed in claim 1, in which the fluid directing means (130) includes an inwardly directed annular orifice (130) which is arranged to direct fluid onto the fluid deflecting surface (140) when the piston (104) is in the second position (Figure 2). A nozzle and valve assembly as claimed in claim 1 or 2, in which said free end of the piston (104) is adjacent said open end of the cylinder (102) when the piston (104) is in the second position (Figure 2). A nozzle and valve assembly as claimed in any preceding claim, and further comprising a rack (146) provided on and along said piston (104) and spaced from said first inlet (110) in a direction away from said open end of said cylinder (102), and a pinion (148) drivingly engaging said rack (146) and mounted in a housing (150) the interior of which communicates directly with the interior of said cylinder (102). A nozzle and valve assembly as claimed in claim 4 and further comprising means (132) for introducing a cleaning fluid into the interior of said cylinder (102) and the interior of said housing (150). A method of supplying a particulate product and a liquid to a container, said method comprising the steps of: a) providing a nozzle and valve assembly (100) comprising a cylinder (102) having an open end, a first inlet (110) leading into the interior of the cylinder (102), a second inlet (118), a piston (104) having a free end and mounted for reciprocating movement in the cylinder (102) at least between a first position (Figure 1) and a second position (Figure 2), the piston (104) permitting communication between the first inlet (110) and the open end of the cylinder (102) when the piston (104) is in the first position, said free end of the piston (104) moving past the first inlet (110) as the piston (104) moves from the first position to the second position so as to prevent communication between the first inlet (110) and said open end of the cylinder (102), a liquid deflecting surface (140) formed on said free end of the piston (104), means (130) on the cylinder (102) in the region of said open end for directing liquid inwardly and on to the liquid deflecting surface (140) when the piston (104) is in the second position, and means (119) for connecting the second inlet (118) with the liquid directing means (130); b) positioning a container (164) beneath the open end of the cylinder (102); c) supplying a particulate product to the first inlet (110) when the piston (104) is in the first position (Figure 1); d) moving the piston (104) from the first position (Figure 1) to the second position (Figure 2) after a desired amount of the particulate product has been supplied to the container (164); and e) supplying the liquid to the second inlet (118) with the piston (104) still in the second position (Figure 2), characterised by supplying a liquid to the second inlet (118) when the piston (104) is in the first position (Figure 1). A method as claimed in claim 6, in which the particulate product is a food product. A method as claimed in claim 6 or 7, and further comprising introducing a cleaning fluid into the interior of said cylinder (102) and into the interior of a housing (150) communicating directly with the interior of said cylinder (102) and mounting a pinion (148) drivingly engaging a rack (146) provided on and along said piston (104).

Inventors: DIVALL JOHN EDWIN, DIVALL, JOHN EDWIN
Applicants: ELOPAK AS, ELOPAK A.S.
Application year: 1992
Main classification: B65B39
IPC codes: B65B39, B65B55