GB2041898A

GB2041898A - Precision Pneumatic Seed Drill

Info

Publication number: GB2041898A
Application number: GB7906223A
Authority: GB
Original assignee: Vears T L
Current assignee: Vears T L
Priority date: 1979-02-21
Filing date: 1979-02-21
Publication date: 1980-09-17

Abstract

A piston 5 reciprocating in a cylinder 4 is provided with a seed receiving pocket 8 in fluid communication via a port 9 with the lower end of the piston. At the upper end of the stroke of the piston the pocket 8 is aligned with a seed inlet aperture 7 in the cylinder wale and due to suction created in the space below the piston a seed is drawn into the pocket. At the lower end of the stroke of the piston the pocket is aligned with a seed outlet aperture 10 in the cylinder wale are due to pressure created in the space below the piston the seed is ejected. Pressure created in the space above the piston as the piston rises causes a jet of air to be directed, via a port 6, at the inlet aperture 7 to blow excess seeds away. <IMAGE>

Description

SPECIFICATION Precision Pneumatic Seed Drill (Metering Unit) The metering units will be mounted on a suitable frame or chassis, which is supported by two wheels and will be towed behind a tractor.

One of two methods may be employed for the actuation of the metering units.

I. By cam-shaft with a variable speed input, driven via a land wheel II. By solenoid, via a variable speed impulse generator, taking the form of a black box, situated in the tractor cab, having facilities for manual intervention. Power being supplied from a 1 2 volt battery via an alternator.

In both cases, seeds will be fed from a hopper via a pipe to each metering unit.

Project Seed Drill-Operating Principle Seeds are deposited by gravity via a pipe to the seed inlet. With the plunger on the upward stroke the seed inlet is blocked. Air is compressed in the space above the plunger and flows down a port in the cylinder body to the seed inlet. This action has the effect of parting the last two seeds in the inlet, causing only one seed to be available for transport to the seed outlet. As the plunger rises, a vacuum is formed beneath the plunger. The plunger continues to rise till the seed chamber lines up with the seed inlet. At this point air rushes into the seed inlet, to fill the vacuum that exists in the seed chamber, and in the process takes one seed with it. The plunger is now at T.D.C.As the plunger continues to travel down the bore, a vacuum is formed in the space above the piston, this causing a suction at the seed inlet, drawing a further seed down the inlet pipe. Also at this time, air is being compressed in the space below the plunger, causing the pressure in the seed chamber via a port drilled from the bottom of the plunger. When the plunger reaches B.D.C., the seed is ejected with a blast of compressed air. The plunger moves back up the bore to collect another seed. End of cycle.

Components Project Seed Drill Components used in one metering unit I Cylinder Body Plunger 4 '0' Rings I Push Rod I Retaining Flange I Return Spring I Collet The cylinder body will be made of a steel which is hard and has good resistance to abrasion, i.e.

chrome steel 0.45%C, 0.9%Mn, .........

Manganese Steel 1.2%C, 12.5% Mn ... E.N. 42, E.N. 45A.

It will have a 1 5mm dia. precisioned bore, and will contain a 1 mm dia. passageway (port) running from the top of the bore to the seed inlet.

It will be threaded at the upper most end (maie thread) 25mm coarse to receive the retaining flange. The cylinder body will have four radial grooves, equally spaced in the bore to receive four 'O' rings.

The plunger will either be made of aluminium or high impact nylon. It will have a 5mm female thread at the top, to locate the push rod. It will have a precision machined finish.

The seed chamber will be machined out, 1 Omm from the bottom of the plunger, and will be intersected by a 1 mm passageway from the bottom of the plunger.

The push rod will be made of medium carbon steel. The spring will be made of spring steel. The retaining flange will either be made of high impact plastic or medium carbon steel machined to fit a 'C' spanner.

Claims

1. A machine for the metering of seeds in a seed drill. Comprising: A means of feeding seeds to individual metering units.

A means of effecting the movement of reciprocating components in the said machine.

A means of metering seeds in and out of the said machine.

A means of metering seeds, said metering means being actuated by solenoid or other such prime mover, wherein the said seed drill contains at least one metering unit.

2. A machine according to claim 1, wherein the reciprocating components are contained in a machined bore, causing a compression and a vacuum at both ends of the bore upon reciprocation.

3. A machine according to claims 1 and 2 wherein seeds are drawn into the metering unit by suction.

4. A machine according to claims 1-3 wherein seeds are deposited from metering unit by compression caused by descending plunger.

5. A machine according to claims 1-4 wherein air is forced under compression from under reciprocating members to seed outlet, thus depositing seeds.

6. A machine according to claims 1-5, wherein seeds are deposited via a pipe to the seed inlet.

7. A machine according to claims 1-6, wherein with the plunger on it's upward stroke the seed inlet is blocked and air is compressed in the space above the plunger and flows down transfer port in cylinder body to the seed inlet causing a parting effect on the last two seeds in the seed inlet, causing only one seed to be available for metering to the seed outlet.

8. A machine according to claims 1-7, wherein as the plunger rises, a vacuum is formed beneath the plunger. At fullest extent of movement in an upward direction, the seed chamber lines up with the seed inlet, causing air at low pressure to enter the seed cavity, thus depositing a seed into the said seed cavity.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Precision Pneumatic Seed Drill (Metering Unit) The metering units will be mounted on a suitable frame or chassis, which is supported by two wheels and will be towed behind a tractor. One of two methods may be employed for the actuation of the metering units. I. By cam-shaft with a variable speed input, driven via a land wheel II. By solenoid, via a variable speed impulse generator, taking the form of a black box, situated in the tractor cab, having facilities for manual intervention. Power being supplied from a 1 2 volt battery via an alternator. In both cases, seeds will be fed from a hopper via a pipe to each metering unit. Project Seed Drill-Operating Principle Seeds are deposited by gravity via a pipe to the seed inlet. With the plunger on the upward stroke the seed inlet is blocked. Air is compressed in the space above the plunger and flows down a port in the cylinder body to the seed inlet. This action has the effect of parting the last two seeds in the inlet, causing only one seed to be available for transport to the seed outlet. As the plunger rises, a vacuum is formed beneath the plunger. The plunger continues to rise till the seed chamber lines up with the seed inlet. At this point air rushes into the seed inlet, to fill the vacuum that exists in the seed chamber, and in the process takes one seed with it. The plunger is now at T.D.C.As the plunger continues to travel down the bore, a vacuum is formed in the space above the piston, this causing a suction at the seed inlet, drawing a further seed down the inlet pipe. Also at this time, air is being compressed in the space below the plunger, causing the pressure in the seed chamber via a port drilled from the bottom of the plunger. When the plunger reaches B.D.C., the seed is ejected with a blast of compressed air. The plunger moves back up the bore to collect another seed. End of cycle. Components Project Seed Drill Components used in one metering unit I Cylinder Body Plunger 4 '0' Rings I Push Rod I Retaining Flange I Return Spring I Collet The cylinder body will be made of a steel which is hard and has good resistance to abrasion, i.e. chrome steel 0.45%C, 0.9%Mn, ......... Manganese Steel 1.2%C, 12.5% Mn ... E.N. 42, E.N. 45A. It will have a 1 5mm dia. precisioned bore, and will contain a 1 mm dia. passageway (port) running from the top of the bore to the seed inlet. It will be threaded at the upper most end (maie thread) 25mm coarse to receive the retaining flange. The cylinder body will have four radial grooves, equally spaced in the bore to receive four 'O' rings. The plunger will either be made of aluminium or high impact nylon. It will have a 5mm female thread at the top, to locate the push rod. It will have a precision machined finish. The seed chamber will be machined out, 1 Omm from the bottom of the plunger, and will be intersected by a 1 mm passageway from the bottom of the plunger. The push rod will be made of medium carbon steel. The spring will be made of spring steel. The retaining flange will either be made of high impact plastic or medium carbon steel machined to fit a 'C' spanner. Claims

A means of metering seeds in and out of the said machine.

9. A machine according to claims 1-8 wherein with the plunger on the downward stroke, a vacuum is formed on top of the said plunger causing seeds to be sucked towards the seed inlet, simultaneously causing a pressure beneath the plunger which enters seed cavity via seed cavity transfer port.

10. A machine according to claims 1-9 wherein, with the plunger at it's fullest extent of downward travel, the seed is projected by compressed air.

11. A machine according to claims 1-10, wherein the metering units will be mounted on a suitable frame or chassis, which is supported by pneumatic tyres and will be either towed by a tractor or self propelled.

12. A machine according to claims 1-11, wherein the metering units are actuated by a solenoid via a variable speed impulse generator, taking the form of a module situated in the tractor cab, actuated by a sensor mounted in one of the wheels of the said chassis.

1 3. A machine for metering seeds as herein described with reference to the accompanying drawings.