GB2084115A - A machine for building wafer sandwiches - Google Patents

Abstract

A machine for building wafer sandwiches comprising a building unit (12) to which individual wafer sheets are successively fed from an input conveyor (10) and which causes the wafer sheets to be stacked in super- imposed relationship to produce a wafer sandwich which is subsequently removed from the building unit by an output conveyor (11). In the building unit (12) the individual wafer sheets are received by a pair of contra-rotating part-circular shelves (14) which convey the sheets forwardly against a stop (21), and, after a degree of rotation, deposit the sheets successively onto a plurality of rails (51) which support the sheets until the sandwich is completed, whereupon the rails (51) are lowered on pivotted arms (52) so that the sandwich is deposited onto the output conveyor (11). The shelves (14) are rotated continuously or intermittently to ensure substantially continuous operation. Alternatively, a second pair of intermittently contra-rotating, part-circular shelves may replace the rails or rails and second pair of shelves may be omitted if conveyor (11) is stationary during stacking. <IMAGE>

Description

SPECIFICATION A machine for building wafer sandwiches This invention relates to a machine for building wafer sandwiches wherein a number of creamed 'wafer sheets are delivered to a building station and stacked in superimposed relationship, and topped with a non-creased wafer to complete the sandwich.

Many such machines have been developed to carry out this operation automatically and at high speed thus to meet the production requirements of the biscuit making industry today. One such arrange ment includes a pair of opposed reciprocating shelf members onto which individual wafer sheets are successively delivered, the shelf members being moved apart in sequence with the delivery thus to drop each sheet onto the immediately preceding sheet. However, this arrangement imposed limitations on production rates, because the delivery of the individual sheets to the building station is limited by the time taken for the shelf members to move apart and return to receive the next sheet.

An object to the present invention is to provide a machine for building wafer sandwiches where the speed limitations previously experienced, are substantially removed.

According to the present invention there is provided a machine for building wafer sandwiches, comprising a building unit, means for delivering individual wafer sheets thereto, and means for removing completed wafer sandwiches therefrom, and building unit comprising a pair of rotating shelf members arranged side-by-side thus to act together to receive successive wafer sheets and rotated in mutually opposite directions to support and convey the individual sheets towards a first held position against a stop, the shelf members being formed such that by continued rotation thereof each sheet is deposited from the first held position into a second held position on a receiving platform below the first held position, and means operable when a com pleted sandwich has been built on said receiving platform, to permit removal of the sandwich from the building unit.

An embodiment of the invention will now be described, with reference to the accompanying drawings in which: Figure 1 is a plan view of a machine made in accordance with the invention; Figure2 is a vertical section taken along line ll-ll of Figure 1; Figure 3 is a view similar to Figure 1 of a modified arrangement; and Figure 4 is a vertical section taken on line IV-IV of Figure 3.

Referring to Figures 1 and 2, the machine compris es an input conveyor 10, preferably in the form of a plurality of parallel conveying bands, and an output conveyor 11 of generally similar construction gener ally aligned with the conveyor 10, but with its conveying surface disposed at a level below that of the conveyor 10, the difference in levels being approximately equivalent to the height or thickness of a completed wafer sandwich to be produced on the machine.

Between the conveyors 10 and 11 is a building unit generally indicated at 12 and including a pair of vertically disposed spindles 13 located one at each side of the building unit at a distance apart substantially equivalent to the width of a wafer sheet. Each spindle 13 carries, for rotation therewith, a pair of rotary shelves 14 and 15 positioned one above the other, the difference in height between them being greater than the maximum thickness of a wafer sandwich to be produced.

The two lower shelves 15 are circular whilst the two upper shelves 14 each define a periphery slightly in excess of a semi-circie and both pairs of shelves may be constructed, as shown, as an annulus connected to the spindle 13 by a number of spokes 16, or alternatively as discs from sheet material. The rotary shelves 14 and 15 are driven by a motor 17 and drive gear generally indicated at 18, in mutually opposite directions to convey the sheets from left to right in Figure 1, a common shaft 19 extending transversely across the machine to drive the spindle 13 simultaneously through right angle transmission gears 20.

On the delivery side of the shelves 14 and 15 are upper and lower fences 21 and 22 which, as will be described, serve as stops to hold the wafer sheets during building of the sandwich. The upper fence 21 is fixed to a cross-member on the machine, and its lower edge is just below the pair of side-by-side shelves 14. The lower fence 22 is mounted on a framework 23 which is pivotable at 24 thus to raise and lower the fence 22 with respect to the fence 21.

In its raised position to which it is resiliently biased, the lower fence 22 has its top edge in line with and in contact with the bottom edge of fence 21, and in this position, the bottom edge of fence 22 is below the lower shelves 15. The fences 21 and 22 are so positioned that the transverse centre line of a wafer sheet abutting the fences is co-incidental with a line extending between the two vertical spindles 13.

The building unit includes a system of rotating guides, which system includes at each side of the machine a pair of vertical rollers 25 disposed one before and one after the associated spindles 13, and driven thereby in rotation by means of drive bands 26 which wrap the driven spindle 13 and the guide rollers 25. Immediately below the guide rollers 25 is a further pair of vertical guide rollers 27 which similarly are driven from the spindle 13 by drive belts 28. The maximum distance between the peripheries of the rollers of each pair 25 and 27 is substantially equivalent to the length of a wafer sheet, whereby as the sheets enter the building unit, they are guided by the rollers until they reach the stop fences 21 and 22.The shaft 19 which drives the spindles 13 is itself driven from the continuously rotating motor 17 and drive gear 18 via a solonoid operated wrap spring clutch 30 so that the shaft 19 is rotated intermittently by one complete revolution.

The conveyors 10 and 11 are driven continuously by the motor 17 via a gear 33 and drive belts 34 respectively. An actuator 31 is connected to the framework 23 thus to lower and raise the fence 22 when required as will be described.

Mounted in association with the input conveyor 10 is a light source and photo cell unit illustrated schematically at 50 adapted to detect the presence of a wafer sheet as it proceeds towards the building unit. The unit 50 transmits a signal to a timing device as known kind (not shown) which after a predetermined delay actuates the wrap spring clutch 30 to cause the shaft 19 to rotate. The photo cell unit 50 also is associated with a counter of known kind (not shown) which when a predetermined number of wafer sheets have passed transmits a signal to the actuator 31 thus to cause the fence 22 to be lowered.

In the operation of the machine the creamed wafer sheets are delivered successively to the building unit 12 by the input conveyor 10, and when each sheet interrupts the light beam in unit 50, the timing device is energised such that when the leading edge of the wafer sheet has reached a predetermined position overlapping the peripheral path of the shelves 14 and 15, a pulse signal is delivered to actuate the clutch 30. Thus the spindles 13 make one complete revolution rotating the shelves 14 and 15 effectively in the direction of water sheet travel. As the cooperating upper shelves 14 rotate, the actuate rims thereof move underneath the wafer sheet as the latter is transferred from the conveyor 10. As the trailing edge of the sheet leaves the conveyor 10 the sheet is wholly supported by the shelves 14 and is driven forwards to abut the upper fence 21.Thus the sheet is maintained in a first held position while the shelves 14 and 15 continue to rotate, the upper shelves sliding underneath the wafer until after one complete revolution they assume the position shown in Figure 2 wherein the straight sides of the semi-circular shelves 14 are clear of the leading edges of the wafer sheet. Thus the wafer sheet drops onto the lower shelves 15 and is maintained in a second held position againstthe lower fence 22. This cycle is repeated until the required number of wafer sheets have passed and been stacked in superimposed relationship on the intermittently rotating lower shelves 15.On completion of the sandwich as detected by the counter, the arrival of the first wafer sheet of the next sandwich at the photo cell unit effects operation of clutch 30 and actuator 31 such thatthe lower fence 22 descends to permit the completed wafer sandwich to be removed from the building unit by the lower shelves 15 and transferred onto the output conveyor 11, whilst the upper shelves 14 are simultaneously conveying the first wafer sheet of the next sandwich towards the fixed fence 21. Before the first sheet decends onto the lower shelves 15, the lower fence 22 is returned to its raised position to serve as a stop for the next wafer sandwich to be built.

Thus wafer sandwiches are continuously built at an appreciably higher rate than was possible with conventional reciprocating shelf members, since at the moment when each sheet is deposited from the upper shelves onto the lower shelves, the leading edge of the next wafer sheet may be received by the upper shelves, and so there is no enforced delay period between receipt by the building unit of successive sheets.

In another aiternative arrangement, the guide rollers 25 and 27 upstream of the spindles 13, in relation to the diretion of travel of the wafers, can be replaced by fixed linear guides 60 (shown dotted in Figure 1 ) arranged one on each side of the input conveyor 10 and extending forwards thereon to a position just upstream of the spindles 13.

Referring now to Figures 3 and 4, wherein like parts are denoted by like reference numerals, in a simplified arrangement, the lower shelf 15 of Figures 1 and 2 is omitted and the output conveyor 11 is extended back so that the start of its conveying run is located immediately adjacent the output end of the input conveyor 10. In this case, a plurality of fixed rails 51 support the wafer sheets in the building unit 12 whilst the sandwich is being produced. The rails 51 are mounted on associated arms 52 pivotted at their left-hand ends as viewed in Figures 3 and 4 and movable by means of pneumatic or hydraulic cylinders 53 which effectively perform the same function as the actuator 31 in Figures 1 and 2 by lowering the rails 51 to bring the bottom surface of a completed sandwich into contact with the surface of output conveyor 11, whereby the sandwich is removed from the building unit.The rails 51 are returned to their raised positions to support the first sheet of the next sandwich before the said first sheet leaves the rotating shelf 14.

In a still further simplified embodiment, the platform assembly comprised by the rails 51 and arms 52 can be omitted, and the output conveyor 11 driven intermittently, the latter remaining stationary while a sandwich is being built. If preferred, the part of the output conveyor operating within the building unit can be separate from a true output conveyor whose conveying run starts outside the building unit. In this case, the true output conveyor can be driven continuously as in the embodiment of of Figures 1 and 2.

It is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible without departing from the scope of the invention.

For example, the wrap spring clutch 30 can be replaced by any other means capable of providing the required single revolution of the rotary shelves when energised by the associated detection means.

Furthermore, the input conveyor 10 and the output conveyor 11 are conveniently driven by the motor 17 in a complete machine of the kind described herein.

In practice, the input and output conveyors of the machine can comprise the output and input conveyors respectively of apparatus upstream and downstream of the machine in a line of wafer production machinery.

Claims (9)

1. A machine for building wafer sandwiches, comprising a building unit, means for delivering individual wafer sheets thereto, and means for removing completed wafer sandwiches therefrom, the building unit comprising a pair of rotation shelf members arranged side-by-side thus to act together to receive successive wafer sheets and rotated in mutually opposite directions to support and convey the individual sheets towards a first held position against a stop, the shelf members being formed such that by continued rotation thereof each sheet is deposited from the first held position into a second held position on a receiving platform below the first held position, and means operable when a completed sandwich has been built on said receiving platform, to permit removal of the sandwich from the building unit.

2. A machine according to Claim 1, wherein said shelf members comprise a pair of co-operating horizontally disposed shelves of generally semicircular shape rotated in opposite directions to support and convey each wafer sheet in turn through the building unit towards said stop, whereby continued rotation of said shelves permits the sheet to fall into said second held position.

3. A machine according to Claim 1 or Claim 2, wherein said receiving platform comprises a second pair of rotating shelf members disposed side-by-side beneath the first mentioned pair of shelf members and rotating therewith, thus to receive and maintain the deposited sheets against a second stop while they are stacked to form a sandwich.

4. A machine according to Claim 3, in which each of the second pair of shelf members is a complete disc or annulus, and each of the first pair of shelf members is formed as a part of a disc or annulus defining a periphery slightly in excess of a semicircle.

5. A machine according to Claim 1 or Claim 2, wherein said means to effect removal of a completed sandwich from the building unit comprises a movable fence against which the sheets are stacked in the second held position, and which is lowered to permit the sandwich to pass onto an output conveyor.

6. A machine according to Claim 1, or Claim 2, wherein said receiving platform comprises at least one rail to support the sheets in said second held position above an output conveyor and said means to permit removal of a completed sandwich comprises a device to lower said rail to a height below said output conveyor thus to deposit the sandwich onto the latter.

7. A machine according to Claim 1 or Claim 2, wherein said receiving platform comprises an output conveyor which is normally stationary in said second held position, and said means to permit removal of a compeleted sandwich comprises a device to drive said output conveyor upon completion of each said sandwich.

8. A machine according to Claim 1, including detection means to sense the presence of a wafer sheet entering the building unit and automatically to cause rotation of said shelf members to receive same.

9. A machine according to Claim 8, wherein said detection means includes a counter to effect operation when appropriate of said means to permit removal of a completed sandwich.