GB2389768A

GB2389768A - Power driven rotary soil cultivator

Info

Publication number: GB2389768A
Application number: GB0213541A
Authority: GB
Inventors: Alan Frederick Rees
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-05-22
Filing date: 2002-06-13
Publication date: 2003-12-24
Also published as: GB0213541D0; GB0211871D0

Abstract

A rotary soil cultivator comprises a flat circular disc mounted onto a shaft which is connected to, and driven by, a petrol or electric motor. A spike connects to the shaft and extends through the disc to form a central ground engaging prong. The disc is fitted with a plurality of other ground engaging prongs which are curved into the direction of rotation. These prongs vary in length, with at least one of the outer prongs being the longest. The disc acts as a depth limiting plate and has a disc hump on its underside. When used in conjunction with a stand-on foot protection plate, the disc hump engages with similar structures on the plate causing the cultivator to adjust its depth in the soil. The cultivator may be fitted with a wide flat handle which, during use, is placed against the operators thigh to prevent counter rotation of the tool. The device may also be fitted with a safety cut-off switch.

Description

( 1 238g / eel, POWERED GARDEN FORK - MK 11

Digging a garden is difficult and heavy work; it is particularly hard for older people or women, many of whom are enthusiastic gardeners. It is the mtension of the present invention to produce a means of digging a garden efficiently but with a minimum of effort.

The powered garden fork is comprised of a heavy Hat circular disc, drawing No. 1. Down through the centre of this disc runs a spike, around the rest of the underside of this disc are positioned a number of curved prongs they all point downwards and are curved to point in a clockwise direction (when viewed from above) these prongs will vary in length, but with at least one of the outer prongs being the longest, no prong will be as long as the central spike and there will be no pror,s attached to the outer most area of the disc. The central spike or "rotating pin" will extend up through the disc to become the drive shaft for a petrol or electric motor, which may or may not be geared. On the outer edge of the under side of the disc will be a corrugation or hump.

The powered fork has a second part, in the form of a "stand on plate", this is a plate which is placed on the ground unrnediately in front of the area to be dug, it will be Dat except for a series of corrugations along its front edge. The forks rotating pin is stuck into the ground in front of the plate so that the prongs are clear of the plate but the outer edge of the disc overhangs the corrugated edge of the plate, when the motor is switched on the prongs are rotated clockwise and the fork Is pushed downward into the soil, the central spike providing a fixed rotation point, as the curved prongs come into contact with the soil they will, due to their shape, tend to pull the fork downward and into the soil, when fully imbedded the disc will come into contact with the soil and stop the downward movement, the prongs, still rotating will then have no choice but to tear up the soil as they rotate, effectively digging it.

The overhang of the disc with its single hump will, with rotation come into contact with the matching hump of the stand on plate, forcing the fork upwards as the humps pass over each other the fork will then again pull into the soil further breaking it up with a rotating and an up and down movement. When firushed at this point, the fork is extracted and moved to the next hump on the stand on plate and so on.

There will be a tendency to counter rotate the tool against the soil resistance, to this end it may require longish handles and an extra handle in the form of a wide fiat handle to be placed against the led thigh ensure that the tool cannot pull out of the operators hands. To further ensure safety a built in twist limiter can be incorporated so that if a strong root is encountered the machine will not injure the user by twisting out of control, this can be achieved by a simple spring loaded switch built into the thigh stop, the spring is calibrated to hold against normal pressure on the thigh whilst in normal use, but if the tool is twisted violently, the pressure against the thigh will over come the spun" and the switch would kill the motor and require resetting before the machine will restart, the prongs could also be sharpened to a certain extent to cut through many lighter roots, a foot guard could also be included into the stand on pate. The switch-off safety can be met in any of a number of ways other than the thigh switch, such as a clutch mechanism which will slip if the fork stops whilst the motor is still runalng, or the sort of cut out system used on clmin saws.

The same up and down movement can be achieved if the disc is mounted at an angle to the central put, the stand on plate would still be required this would achieve a smoother up and down movement but would make the construction more complicated.

% It may be necessary for the fork to be made with more than one set of prongs which will be interchangeable by means of a simple threaded joint or bayonet type connector in the central pin (drawing No 1). In this way the prongs can be short for a first dig and a longer set for deeper digging or varied to suit different soil or clay types.

The foot guard on the stand-on plate could also be positioned tight against the corrugations so that the fork could be placed with the edge of its disc touching the foot guard to ensure correct contact between the corrugations and the hump as the fork goes down into the ground

Claims

Powered Garden Fork - NfK
2 1 Claims I

I. A power driven garden fork, which uses a rotation movement as the means of digging.

9. A power driven garden fork as claimed in], which has a pointed central prong longer than any other prong, around which the other prongs rotate.
3. A power driven garden fork as in clanns I and 2 which has a number of digging prongs of various length and distance from the central prong with at least one ofthe longest being furthest from the central prong.
4. A power driven garden fork as in claims I to 3 where all the prongs except the central prong are pointed and curved into the direction of rotation.
5. A power driven garden fork as in claims 1 to 4 where all the digging prongs are fixed to a flat plate, which controls the depth of the digging.
6 A power driven garden fork as in claims 1 to 5 where the central rotating prong is also the shaft by which the fork is driven.
7. A power driven garden fork as in claims 1 to 6 where the outer edge of the underside of the plate carries a corrugation.
8. A power driven garden fork as in claims 1 to 7 where a stand-on plate includes a foot protector and corrugations to react with the corrugation under the plate.
9. A power driven garden fork as in claims 1 to 8, which includes handles long enough to control counter rotation caused by soil resistance including a possible thigh stop.
10. A power driven garden fork as in claims 1 to 9 which includes a safety control switch such as a chainsaw, which will require resetting.

I I. A power driven garden fork as in claims ltolO where the plate is mounted at an angle to the prongs in place of the corrugation on the underside of the plate.

] 2. A power driven garden fork as in claims I to I I where the whole of the plate and prong assembly can be exchanged for a different assembly with different length prongs for different depth digging.