GB2060468A

GB2060468A - Apparatus for Depositing A Succession of Measured Doses

Info

Publication number: GB2060468A
Application number: GB7935451A
Authority: GB
Original assignee: Baker Perkins Holdings Ltd
Current assignee: Baker Perkins Holdings Ltd
Priority date: 1979-10-12
Filing date: 1979-10-12
Publication date: 1981-05-07
Also published as: GB2060468B

Abstract

In order to improve the operation of a depositor for depositing a succession of measured doses onto horizontally moving receiving surfaces, the hopper 4 is pivotally mounted at 5, above its centre of gravity, to a support frame 2 which is in turn pivotally mounted at 3 to the stationary, main frame 1 of the apparatus. The outlet of the nozzle 7 is moved horizontally by an assembly 25, which acts on the nozzle-hopper assembly, and is moved vertically by an assembly 16, which acts upon the support frame. <IMAGE>

Description

SPECIFICATION Apparatus for Depositing a Succession of Measured Doses Background of the Invention This invention relates to apparatus for depositing a succession of measured doses of for example a viscous substance on to a generally horizontally-moving receiving surface or succession of receiving surfaces. In the baking, biscuit-making and confectionery arts, the apparatus is known as a depositor, and can be used for instance for dough or batter in the production of cakes or biscuits, including fruited and plain cake, eclairs, choux paste, meringues, marshmallow, Viennese, fairy cakes, cup cakes and sponge drops, also for fillings for tarts or pies, and for any other suitable substance.The viscosity of the substance will depend upon the application, but it need not be viscous-the substance can be in the form of for instance doughs or batters, viscous liquids or pastes.

The receiving surface could be for example a steel band conveyor or a succession of baking tins, pans or trays or pie or tart cases.

In such apparatus, the main requirements are precision, reliability and speed whilst keeping the cost and weight as low as possible.

The Invention The present invention provides apparatus as set forth in Claim 1 and a method as set forth in Claim 12. Claims 2 to 10 claim preferred features of the invention.

The apparatus of the invention enables the speed to be increased without grossly affecting the presision and reliability and whilst maintaining versatility; the apparatus is versatile in that it can deposit substances with widely-varying specific gravities, e.g. from heavy fruited cake batters to comparatively thin sponge cake batters and highly aerated batters.

Description of Preferred Embodiment of the Invention The invention will be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of apparatus in accordance with the invention, when in the middle of a depositing stroke; Figure 2 is an end view of the apparatus, looking in a direction of the arrow II in Figure 1; Figure 3 is a plan view of the apparatus; Figure 4 is a diagram of the pneumatic circuit of the apparatus, and Figure 5 shows, in side view, a typical path of the nozzle outlet, on an enlarged scale relative to that of Figure 1.

The apparatus shown in the drawings has a stationary main structure or frame 1. To the main frame 1 is pivoted for limited oscillatory motion a support structure or frame 2 for movement about a first, horizontal axis 3 which is transverse to the movement of the receiving surface(s) referred to below. A container or hopper 4 is pivotally mounted on the support frame 2 for limited oscillatory movement about a second axis 5 which is parallel to and at the same height as the first axis 3 and which is directly above the centre of gravity of the hopper 4 alone when the hopper 4 is in the position shown in Figure 1. As parts are fixed to the hopper 4 in an off-centre position, the centre of gravity of the hopper 4 and parts fixed thereto, whether the hopper 4 is full or empty, is nearly directly below the axis 5, but not exactly so.

A A depositing head 6 is fixed to the lower part of the hopper 4, and the depositing head 6 has a row of nozzles 7. The depositing head 6 can be of any suitable type. In one well-known type, each nozzle 7 is associated with a common, twoposition rotary valve 8 and a plunger unit 9.

A housing 10 contains a pneumatic pistonand-cylinder assembly 11 (shown only in Figure 4) and adjustable stops (not shown) to operate the bank of plunger units 9 via a cross-arm (not shown), and the weight of the substance deposited can be changed by altering the stroke of the pneumatic piston-and-cylinder assembly 1 A similar housing 12 (see Figure 2) contains a further pneumatic piston-and-cylinder assembly 1 3 (shown only in Figure 4) for oscillating the valve 8. Yet another piston-and-cylinder assembly 13' (shown only in Figure 4) is provided to rotate the nozzles 7 by way of a rack and pinions (not shown) for producing scroll goods, for example star-shaped products with spiral/helical flutes.

The far end of the support frame 2 is pivoted to a cross-beam 14 about a third horizontal axis 1 5 which, in the position shown in Figure 1, is at the same level as the axes 3 and 5. The cross-beam 14 is connected to the rams of three pneumatic piston-and-cylinder assemblies 16, 1 7 and 1 8 whose cylinders are fixed to a lower cross-beam 19 which in turn is connected through heightadjusting mechanisms 20 and a pivot axis 21 to the main frame 1 of the apparatus. The heightadjusting mechanisms 20 adjust the height of the outlets from the nozzles 7 above the receiving surface(s).The height-adjusting mechanisms 20 can be of any suitable type, and are shown as having two screw-jacks which can be turned by two handwheels 22 (as shown) or for instance by a single handle if the screw-jacks are interconnected by for instance sprockets and a chain.

A connecting bar 23 is fixed to the depositing head 6 and is pivoted at 24 to the ram of a pneumatic piston-and-cylinder assembly 25 whose cylinder is pivoted to the main frame 1 at 26. The piston-and-cylinder assembly 25 is shown in its mid-position in Figure 1, and is provided with adjustable stops (not shown) so that either end of its stroke can be adjusted.

In Figures 1 and 2, the reference 27 indicates the plane of a conveyor, which can for instance be driven by a chain and sprocket drive from an independent electric motor (not shown); alternatively, the conveyor could be driven by a pneumatically-operated ratchet (and for instance a chain drive) actuated by a piston-and-cylinder assembly (not shown), so that the conveyor moves intermittently between depositing strokes of the head 6. If the conveyor is independently driven, it can be coupled to cam switches (not shown) for controlling the pneumatic circuit of the apparatus, or, whether the conveyor is independently driven or not, the apparatus can be controlled by cam switches which are coupled to for instance a continuously moving conveyor band onto which the first-mentioned conveyor discharges or by another independent drive.The conveyor may be a steel conveyor band which forms the receiving surface, or can carry trays or pans forming the receiving surfaces. If there are abutments for properly spacing the trays or pans, or if the trays or pans are fixed to the conveyor, the apparatus should be controlled by cam switches coupled in some way to the conveyor; alternatively, if there are no abutments and the trays or pans are not fixed, a conventional brake mechanism, operated from the cam switches, can be used to position the trays or pans correctly on the conveyor.

Figure 4 shows the pneumatic circuit. The piston-and-cylinder assembly 16 acts as a linear actuator or power assembly for oscillating the support frame 2 with respect to the main frame 1, while the piston-and-cylinder assemblies 1 7, 1 8 act as counterbalancing assemblies, as explained below. The piston-and-cylinder assembly 25 acts as a linear actuator for oscillating the hopper 4 with respect to the support frame 2.

There is a main reservoir 29, which can be kept at for instance 80 p.s.i. All the piston-and-cylinder assemblies except 1 7 and 18 are connected to the main reservoir 29 by way of flow regulators 30, solenoid valves 31 and pressure regulators 32 having pressure gauges 33. The solenoid valves 31 are controlled by the cam switches referred to above.

The piston-and-cylinder assemblies 17, 18 are connected to a special reservoir 34 which is contained within the lower cross-beam 1 9 (Figure 2) and which is connected to the main reservoir 29 by way of a non-relieving pressure regulator 35 having its pressure gauge 33. The pressure regulator 35 allows air to pass from the main reservoir 29 into the special reservoir 34, but not back again, and maintains the special reservoir 34 at a pressure which is not lower than say 60 p.s.i., thereby tending to thrust the support frame 2 upwards. When the support frame 2 is lowered by actuating the piston-and-cylinder assembly 16, the pressure regulator 35 prevents air passing out of the special reservoir 34 and the pressure in the special reservoir 34 rises, for instance to 100 p.s.i.This increase in pressure gives the nozzles 7 a rapid lift at the end of the deposit stroke. The pressure regulators 32 can be set so that the remaining piston-and-cylinder assemblies operate at say 50 p.s.i.

The arrangement is such that the pressure in the reservoir 34 can assist in causing the assemblies 1 7 and 18 to thrust the hopper 4 upwards, and also cushions the hopper 4 towards the end of the downward stroke.

The operation is in the following sequence, starting from the termination of the depositing stroke, which is point 34 in Figure 5 (in fact point 34 is not on the path of the nozzle outlet when the apparatus is in continuous operation): 16 retracted, 25 advanced, 16 advanced, 25 retracted, and so on. The plunger assembly 11 causes the substance from the hopper 4 to be deposited from point 35 to point 36, i.e. along the lowermost part of the loop-shaped path of the nozzle outlet, which lowermost part extends generally horizontally. More precisely, the lowermost part is a large radius arc centred on the axis 5, and the distance between the nozzle outlet and the axis 5 should be as large as practicable so that the nozzle outlet follows as straight a path as possible during deposit.Except in apparatuses where a deliberate retardation of the movement of the nozzle outlet is provided, the nozzle outlet is arranged to move at the same velocity as that of the conveyor. The effective connection between the bar 23 and the main frame 1 during vertical movement of the support frame 2 provides roughly a parallel-arm linkage and constrains the hopper 4 and nozzles 7 to descend and rise approximately vertically before and after deposit. It will be seen from Figure 5 that there is slight overlap in the actuation strokes of the assemblies 1 6 and 25, so that the corners of the path are radiussed.

The operation of the depositing head 6 and nozzles 7 is not described in detail because it is well-known. The nozzles 7 can be arranged such that, at the finish of their extrusion stroke, their outlets are within the blob of substance which has been deposited. The rapid substantially vertical movement of the nozzles 7 after the end of the depositing stroke, as the conveyor moves onward, causes the nozzles 7 to move rapidly up from and relatively slightly backwards from, the deposited substance; this can avoid "tails" on products.

Any suitable switching, such as limit switches or pneumatic switches, can be used instead of the cam switches referred to above.

The pneumatic operation of the apparatus has enabled levers and connecting rods to be largely eliminated, and there is a substantial reduction in the weight and inertia of oscillating or reciprocating parts. In addition, the apparatus is very simple. Furthermore, the axes of movement of the support frame 2 and hopper 4 can be adjusted with ease.

Placing the fulcrum or pivot axis 5 of the hopper 4 above its centre of gravity utilises the mass of the hopper 4 and associated parts, and of the substance to be deposited, to naturally assist its return to the vertical plane, and the apparatus is capable of high speed operation, for instance up to 100 strokes per minute, depending upon the type of produce, range of movement of the nozzle outlets, nozzle cross-section and width of machine. The conveyor speeds can be up to 5 metres per minute for a conveyor band or 10 metres per minute for a chain conveyor propelling pans or trays.

If a ratchet-driven intermittently-moving conveyor is used, the assembly 25 can be locked in its central or mid-position, or a fixed-length rod or link could be provided in place of the assembly 25.

Claims

1. Apparatus for depositing a succession of measured doses of a substance onto a generally horizontally-moving receiving surface of succession of receiving surfaces, the apparatus comprising: a main structure; a support structure mounted on the main structure for limited oscillatory movement with respect to the main structure about a first, horizontal axis (which will be transverse to the movement of the receiving surface(s));; a container for containing a reserve of the substance, the container being mounted on the support structure for limited oscillatory movement with respect to the support structure about a second axis which is parallel to the first axis, is substantially spaced from the first axis in the horizontal sense so that the limited movement of the support structure with respect to the main structure causes the container to move up and down, is at a substantially higher level than the centre of gravity of the full container and parts fixed thereto, and is positioned generally above the position of the centre of gravity of the full container; at least one depositing nozzle mounted on the lower part of the container; and means for oscillating the support structure with respect to the main structure and for oscillating the container with respect to the support structure so that the nozzle outlet moves, in a vertical plane, around a loop-shaped path which has a bottom part extending generally horizontally.

2. The apparatus of Claim 1, wherein the first and second pivot axes are at the same level.

3. The apparatus of either of the preceding Claims, wherein the oscillating means comprises a linear actuator for oscillating the support structure and a linear actuator for oscillating the container.

4. The apparatus of Claim 3, wherein the linear actuators are pneumatic rams.

5. The apparatus of any one of the preceding Claims, wherein the oscillating means comprises a power piston-and-cylinder assembly for oscillating the support structure and a counterbalancing piston-and-cylinder assembly which tends to thrust the support structure in such a direction that the container is moved upwards, the counterbalancing assembly being connected to a pressure fluid reservoir so that the pressure in the reservoir rises when the container is moved downwards.

6. The apparatus of Claim 5, and arranged such that the pressure in the reservoir assists in causing the counterbalancing assembly to thrust the container upwards and also cushions the container towards the end of the downward stroke.

7. The apparatus of any one of the preceding Claims, wherein the oscillating means comprises a drive for the container and a drive for the support structure, the drives being arranged to operate alternately with a small overlap so that the path of the nozzle outlet is approximately rectagular with curved corners.

8. The apparatus of any one of the preceding Claims and arranged such that the nozzle outlet descends and rises approximately vertically.

9. The apparatus of Claim 3 and 8, wherein the linear actuator for oscillating the container is pivoted to the main structure about an axis generally below said first axis and is pivoted to a part rigidly fixed to the container about an axis generally below said second axis, the linear actuator extending generally parallel to the support structure.

10. The apparatus of any one of the preceding Claims, and associated with a conveyor for, or providing, the receiving surface(s), the velocity of the conveyor being in the same sense as that of the nozzle outlet in said lowermost part of its path.

11. Apparatus for depositing a succession of measured doses of a substance, substantially as herein described with reference to, and as shown in, the accompanying drawings.

12. A method of depositing a succession of doses of a substance onto a generally horizontally-moving receiving surface or succession of receiving surfaces, comprising using the apparatus of any one of the preceding claims.