GB2155296A - Seed dispenser - Google Patents

Abstract

A hand-held device for singling seeds comprises a suction nozzle, the air-flow through which is controlled by finger pressure. Control may be effected by covering and uncovering an aperture in the side of the nozzle or by a push-button valve 18,22 operable to connect nozzle bore 17 to suction line 23 to pick up a seed and to pressure line 24 to release the seed. <IMAGE>

Description

SPECIFICATION Seed dispenser This invention relates to a manually operable seed dispenser for horticultural or agricultural use. With the advent of modern methods of plant propagation, especially with such methods, for example, as the use of peat blocks in which usually a single seed is germinated and then transferred to a growing-on situation without disturbing its root system, the problem arises of separating seeds for sowing singly form a bulk supply. The problem is of course accentuated when seeds of differing sizes have to be dealt with. Various systems have been proposed, such as pelleted seeds, which go some way to solving the problem by making the seeds easy to handle by enrobing them with a bulky material. However, such methods tend to be expensive, since packaging and other costs are high.

According to a feature of the invention a manually operable seed dispenser comprises a hand held body having a nozzle the bore of which is no greater than the smallest seed it is desired to handle, a suction source, means for conducting air from the nozzle to the suction source and means for controlling the flow of air from said nozzle to said source in such a way as to permit the dispenser to pick up a single seed when the air is flowing through the nozzle and to cause it to drop off when the flow stops or is reversed.

In its simplest form the body and the suction source are combined in a bellows or compressible bulb the elasticity of which will restore it to the uncompressed state and so create the necessary suction and. the nozzle is quite small, such as of the order of size of a hypodermic needle. These may vary in size but I have found that even a small gauge of needle such as will pick up a single cabbage seed is capable of dealing also with quite large seeds.

Another simple form of the invention which is more appropriate to use by commercial growers or large scale amateur use comprises a body in the form of a tube with a suction connection at one end and a nozzle at the other, with a hole in the tube wall which can be covered by a finger to control the flow of air. This implies the availability of an in-built or separate continuously operating suction source, such as a motor-operated fan, and although this is adequate for many purposes there are occasions when only a limited capacity of suction source is available. In such a case, according to a feature of the invention the body is provided with a valve which, when operated connects the source to the nozzle, and when in a different position disconnects the source from the nozzle.Such a valve may be arranged in a further form of the invention, as a result of further movement or during its release motion to connect the nozzle for a short period to a source of pressure gas so as to blow the seed off the nozzle. According to a further feature of the invention the source of pressure gas may be combined with a source of liquid or powder material for treating the seeds, for example, for applying to them a fungicide or other substance for preserving them from attack.

It is, of course, necessary to prevent the seeds from entering the nozzle, and ordinarily this may be achieved simply by making the orifice smaller than the size of the seed. However, when exceptionally small seeds are involved an alternative is to cover the point of the nozzle with a filtering medium such as an element of fabric, gauze or felt.

The size of the orifice in the nozzle will be determined by the flow characteristics of the system, so that if a continuous and copious flow is available the nozzle aperture may be large. It should not ordinarily be larger than about 3 mm. in diameter, and preferably less, e.g. 1mm. The optimum can be determined empirically with reference to the air flow, the negative pressure of the source, and the mass, shape and size of the seeds it is desired to handle.

The invention also embraces a manually operable seed dispenser as above defined combined with a suction source in the form of an motor driven centrifugal fan or a water-operated ejector pump. It also comprises a seed dispenser as defined above combined with a suction source in the form of a bellows acting under a spring to cause it to expand and draw in air. This may be provided with a one-way valve to enable air to be discharged easily when the bellows is compressed which may conveniently be arranged to by performed by foot pressure. Thus, with the bellows arranged on the ground and connected to the body by a flexible hose, a single operation by the foot may be sufficient for quite a large number of transfers of seeds from one position to another.

Other features of the invention will be apparent form the following description taken in conjunction with the accompanying drawings in which: Figure 1 is a diagramatic view of a simple nozzle combined with a suction source, Figure 2 is a diagramatic view of a nozzle with air-economising means for controlling air from a suction source and if desired also from a pressure source, and Figure 3 is a diagramatic view of a foot-operated combined suction and pressure source.

Referring first to Figure 1 a tube 1, which can be of glass, metal or plastics material, terminates at its lower end in a nozzle portion 2 having a small orifice therethrough. The opposite end of the tube 1 is connected by a flexible tube 3 to the eye of a fan 4 which is driven by a motor 5. Air is thus sucked into the tube 1 and expelled to atmosphere by the fan 4. The tube 1, which is of a size that can be conveniently held in one hand in the manner of a pen or pencil is provided with a hole 6 in its side wall in a position where it can be covered by the pad of a finger of the user. When this is done, air which previously entered through the hole 6 no longer does so but, instead, air is caused to enter through the orifice in the nozzle 2.If the point of the nozzle is then moved, or has already been moved, into the proximity of a seed among a bulk supply of them spread out on a flat surface, that seed will be sucked on to the end of the nozzle, and may be thus transferred to another position such as in a pot, or seed tray or a peat block, or into position in a seed drill in open ground. It thus becomes possible to sow seeds singly at great speed and with high accuracy. A single nozzle will cope with a wide variety of seed sizes, but in any event changing to a nozzle of different size can be a rapid and inexpensive manoeuvre.

In some cases it may be convenient to use an evacuated vessle as a source of suction and in Figure 2 there is illustrated a dispenser with an air economy valve appropriate to such use. In this form of the invention a hand-held body 11 has a nozzle 11 screwed on to its end and sealed to it by a gasket 12. The body has a cross-bore 13 with a blind counterbore 14 providing a shoulder 15. A longitudinal bore 16 forms a communication between the bore 13 and an orifice 17 in the nozzle 11. A valve element 18 with a cross bore 19 is fitted into the bore 13 and is held against a retaining ring 20 by a spring 21 in the counterbore 14. The valve element 18 has a push button 22 and a spring snap ring 22a is located between the element and the spring 21. A bore 23 terminates in the upper wall of the bore 13 as does an adjacent bore 24.The bores 23 and 24 are connected to suction and pressure sources respectively, and as will be seen from the drawing are normally closed off by the valve element 18. When the push button 22 is pressed the valve element 18 will slide in the bore 13 until the snap ring 22a seats on the shoulder 15. At this point the bore 17 is placed in communication through the bore 19 with the suction source. This enables a seed to be picked up by the nozzle 11. When it is desired to drop the seed off the end of the nozzle the push button 22 can be released to cut off the suction.

Alternatively, if the seed is one which is difficult to dislodge, for example because it has been treated with something or because it has partly germinated and is therefore damp, instead of releasing the valve it may be pushed further into the body 10 so as to cause the snap ring 22a to snap over. This permits the valve element to move through a position in which its bore connects with the pressure bore 24. As it passes this position therefore, a puff of air is delivered to the nozzle 11 and the seed is dislodged. A second, back-up puff will be delivered as the push button 22 is released, but very little air will be used. Moreover, air will be used in the suction line only while the seed is held on the end of the nozzle, so that pre-charged pressure and suction vessels can be used for handling quite a large number of seeds.

In Figure 3 of the drawings there is shown a bellows form of suction vessel, which may be combined with a similar pressure vessel. Both may be operated by foot pressure. The suction bellows 30 is arranged with its base 31 on a foot board 32 and its upper face has a pair of diametrically arranged pins 33 which engage in slots 34 in a stirrup 35 of a lever 36 pivoted on the foot board 32. The lever 36 is provided with a foot pedal 37. The pins 33 operate in vertical guides in a yoke 38 attached to the board 32. The bellows 30 has an internal tension spring 39 urging the bellows to its collapsed position. To permit this a non-return valve 40 is fitted for venting of any air in the bellows. To charge the suction vessel the pedal 37 is depressed to raise the top of the bellows and create a partial vacuum, the stirrup 35 being held in the upper position as shown, by a latch 41.The partial vacuum can be applied through a connection 42 to a device of the kind shown in Figure 2.

If desired, the suction vessel can be combined with a, similar, pressure vessel and this is shown at 50, comprising a bellows the base 51 of which is common with the top of the bellows 30. In this case the bellows has an internal compression spring 52 urging the bellows to its expanded position, air being admitted, when this occurs, through a non-return valve 53. The top of the bellows 50 is attached to the yoke 38. Thus, when the latch 41 is tripped and the bellows 30 collapses, the bellows 50 expands and fills with air. When the pedal 37 is depressed the air in the bellows 50 will be compressed and can be applied through a connection 54 to the pressure connection of a device of the kind shown in Figure 2. Since the pressure air is used only in puffs of very short duration, while the suction air is used during the whole of each seed transport operation, the relative sizes of the two bellows may be chosen accordingly, although for convenience of illustration they are shown as being the same size.

It will be appreciated that the drawings are schematic and by way of example only and that variations may be introduced without departing from the scope of the invention.

Claims (1)

1. The invention as set forth.