GB2364497A

GB2364497A - Motorised rake

Info

Publication number: GB2364497A
Application number: GB0105813A
Authority: GB
Inventors: Federico Velo
Original assignee: VALEX SpA
Current assignee: VALEX SpA
Priority date: 2000-07-07
Filing date: 2001-03-09
Publication date: 2002-01-30
Also published as: GB0105813D0; ITTV20000029V0; IT251483Y1; ITTV20000029U1; DE20106862U1

Abstract

A motorised rake comprises a motor, a rotating cylindrical body on an axis parallel to the ground which supports a group of tools (7, figure 4). Each tool comprises a spring (71, figure 2) with at least one tooth 72 that projects from the body. There is a transmission mechanism between the motor and the body, a guide handle, wheels to move the apparatus along the ground and controls for starting and stopping the apparatus. There may be mechanisms to regulate the working height of the tools and a system to collect material removed by the machine. A rotating support structure for the a motorised rake includes the body which is made up of at least two semi-casing 3, 4 joined together, with each semi-casing having openings 32, 42 from which teeth 72 of tools (7) project. One end of joined semi-casings 3, 4 includes the transmission mechanisms and the body houses at least one shaft (6, figure 4) fastened to one of semi-casings 3, 4 for fixing tools (7).

Description

2364497 5 ROTATING SUPPORT STRUCTURE FOR A SET OF TOOLS ADAPTED TO BE

APPLIED TO A MOTORISED RAKE, AND RELATED MOTORISED RAKE The present invention relates to a rotating support structure for a set of tools adapted to be applied to a motorised rake, and related motorised rake.

15 The invention has particular, but not necessarily exclusive, application in the sector involved in the manufacture of gardening apparatus, also known as aerators or scarifiers, used in the preparation and selective cleaning of the ground.

20 BACKGROUND ART

The object of traditional motorised rakes is to remove grass, weeds, small pieces of wood and various waste material which with time, due to their being left lying on the ground, form a compact, resistant surface layer which, on the one hand blocks oxygenation of the underlying layers, and on the other hand blocks the 25 permeation of water and other nutritional substances.

This situation leads to the roots of the grass being choked.

Once the material has been removed, the said motorised rakes have a system to 30 feed the material into a container which is an integral part of the machine's equipment or, as an alternative, the material may be deposited on the ground to be collected later with either a manual rake or with a lawnmower.

The small furrows that are formed in the ground allow water and other nutritional substances to penetrate more easily into the depths of the soil, 5 making it easier to reach the roots of the grass. Regarding the depth and the distribution of the small furrows, they are calculated so that the grass is not ruined, and to keep the soil in the underlying layers compact.

From a structural point of view, the said motorised rakes are supplied 10 with at least one motorised tool in order to make it easier to use and more efficient compared with models driven manually.

Typically, motorised rakes used for the care and maintenance of lawns are made up of a framework or support chassis in order to support the drive 15 unit and the transmission mechanism between the motor and at least one structure that supports the work tools, the work tools themselves and the wheels or similar means for moving the apparatus along the ground. The apparatus is usually driven or guided by hand with a handle that is connected to the lower part of the chassis or support framework, and 20 extends in order to be held better by the operator. The controls are positioned on the handle close to the grip, in order to start or stop the machine, or regulate the rotation speed of the shaft that supports the tools. As previously said, there may also be a container to collect the material picked-up by the apparatus.

STATE OF THE ART With a traditional motorised rake, the tools are made up of a series of pointed teeth, positioned around a tool-holder shaft witha rotation axis that is basically parallel to the ground. The teeth penetrate into the 30 surface of the ground, forming small furrows with a pitch equal to the pitch of the teeth on the rotation axis. The depth of penetration varies according to the type of ground being worked. The teeth may be positioned according to rows parallel to the rotation axis or, more commonly, in a spiral form around the rotation axis in order to guarantee, 35 in a non-continuous form, teeth in contact with the ground. These 5 working conditions guarantee a regular, continuous operation of the motor, thus safeguarding the transmission mechanism and the supports for the shaft to which the tools are fixed. The tools may be made up of a rigid body, but it is more common to find tools with elastic properties, leading to a more gradual and progressive contact with the ground.

10 Typically, this latter requisite is obtained by means of a metallic cord, bent into a spiral shape to form a shape similar to a spring, with one end straightened and pointing radially with respect to the rotation axis of the tool-holder shaft, which sticks out to form,the operative part of the tooth. The opposite spring-type part is fixed to the tool- holder shaft, to give a 15 torsion action.

Amongst t he most common proposals for tool-holder shafts that are worthy of a mention, are the ones featured in patent No EP0024696 (Black & Decker). In this patent, there is a first proposal. which basically 20 consists of a rotating shaft with rectangular heads fixed to the ends. Each corner of the heads, on the side facing the rotating shaft, engages the end of a flexible cable which continues along the whole length of the rotating shaft, and is fastened to the second head. The purpose of the said cable, which is inserted co-axially, is to support a number of contiguous tools.

25 Each tool has a spiral-type coil in metallic cord, which in this case is all the way around the said cable, with the two ends straightened and radial with respect to the rotating shaft. One of the ends presses tangentially on the rotating shaft, resisting against the action of the other end, which forms the tooth that penetrates into the ground. In this case, EP0024696 30 also describes a formation of cables that are not parallel to the rotating shaft, but slightly off-line in order to form an array of tools in the form of a helix, in order to guarantee the continuity of its contact with the ground.

4 5 Patent EP0024696 also describes a second solution for a tool-holder shaft.

This solution foresees the use of a number of modular discs that, when packed together, form a drum which is supported by the rotating shaft.

Each disc has seats around its perimeter which, being open on one side, carry a corresponding tool. The tools are fixed in each of the said seats 10 by a protruding pin, which is inserted co-axially to the spiral-form coil, which is part of the tool previously described. In this case, one end of the said tool is forced against the back of the said seat, while the opposite end, which acts as a tooth, sticks out from the disc in a radial direction with respect to the rotating shaft.

Tools arrayed in a spiral pattern on a motorised rake are also described in patent No US4467591 (Dynie). In this case, there is also a description of a rotating shaft fastened onto the end of a transmission drive, with a number of tools fastened directly to the rotating shaft. Each tool is made 20 up of a metallic cord wrapped in a spiral form and divided in two offline bodies, in order to form two rings joined together on two different levels.

The first ring allows the co-axial insertion of the rotating shaft, fastening the first end of the tool, while the second ring has the end straightened to form a tooth that sticks out in order to act upon the ground.

DRAWBACKS The type of apparatus described up to this point is perfectly functional, if it were not, for the manufacturing costs, which nowadays seem excessive, leading to a limited distribution of this type of tool. The cost of the 30 support structure for the tools is high compared with the overall cost of the apparatus, especially the tool-holder shaft which is the most important component.

Secondly, the solutions proposed regarding the tool-holder body are, 35 generally speaking, rather complex regarding the assembly phase, so that 5 it is quite clear that specialised personnel is required and the. time required is not acceptable on an industrial scale.

The third, but not last, aspect regards the fact that it must be possible to intervene on the tool-holder body. Currently, these operations are 10 difficult, especially with regards the replacement of the tools in an acceptable time, and all other operations related to maintenance.

If these considerations are taken into account, it is,easy to imagine how important it is to find alternative solutions.

One of the aims of this invention is to overcome the aforementioned drawbacks.

SUMMARY OF THE INVENTION

20 This and other aims are achieved with the invention according to the characteristics in the attached claims, solving the aforementioned problems by means of a rotating support structure for a set of tools adapted to be applied to a motorised rake, comprising:

a motor; 25 a rotating cylindrical body on an axis that is parallel to the ground, that supports a group of tools, with each tool being made up of a spring with at least one projecting tooth, and positioned in a radial pattern with respect to the rotating cylindrical body; transmission mechanism between the motor and the rotating 30 cylindrical body; a guide handle for the operator; wheels to move the apparatus along the ground; controls for starting and stopping the apparatus and, if foreseen, controls for regulating the motor and mechanisms to regulate the working 35 height of the tools; 6 5 if foreseen, a system to collect the material removed by the apparatus.

The said rotating support structure comprises at least two semi-casings joined together to form a body that extends longitudinally of a rotation 10 axis of the structure and from which a tooth end of at least one tool projects. Preferably each of the semi-casings has openings through which the teeth of the tools project. One end of the joined semi-casings may include transmission mechanisms and house at least one shaft. Ends of the shaft may be fastened to at least one of the se m'i-casings, and be 15 inserted co-axially of a ringed body of each tool. An opposite end of each tool from the tooth may press against the inside of the respective semi-casing.

ADVANTAGES 20 In this way, through the creative contribution that has the effect of constituting an immediate technical progress, various advantages are achieved.

The first aim is to manufacture a tool-holder shaft for spring-type teeth at 25 a lower cost compared with current models.

The second aim is to manufacture a rotating tool-holder structure for spring-typ teeth that guarantees the wear and functionality characteristics required for the correct operation of the apparatus.

A further aim regards the fact that such a tool-holder structure allows quick, easy assembly of the teeth, and its positioning on the chassis or frame, in order to use low-cost specialised personnel on an assembly line,

an advantage that, for the consumer, means a good quality/price ratio.

7 5 Finally, by reducing the vibrations, the correct functioning of the apparatus lasts longer, and wear of the components in the transmission mechanism is reduced.

These and other advantages, with the aid of the included drawings, will 10 be outlined in the following detailed description of various preferential uses of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. I is a three-dimensional drawing of a r6tating tool-holder 15 structure assembly.

Fig. 2 is a view of the inside of one of two semi-casings that form the rotating structure, and to which tools are attached.

Fig. 3 is a side assembly view of the rotating tool-holder structure shown in the previous Figures.

20 Fig. 4 is a longitudinal, sectional view of the rotating tool-holder structure shown in Fig. 3.

Fig. 5 is a head-on view of the rotating tool-holder structure shown in the previous Figures.

Fig. 6 is an assembly drawing of a variation of the rotating 25 structure shown in the previous Figures.

Fig. 7 is an exploded view of the rotating structure shown in Fig.6.

DESCRIPTION OF EMBODIMENT EXAMPLES

With reference to the above Figures, an apparatus for gardening 30 purposes, in particular a motorised rake, has a rotating tool-holder structure (A, Al), supported at its ends by two small shafts (1, 11) linked to the frame or chassis of the apparatus. The rotating tool-holder structure (A, Al) is driven by transmission mechanisms and by a motor, which is also supported by the frame or chassis of the apparatus. Regarding the 35 transmission mechanisms, in this case they are belt-driven with at least 5 one pulley (2) mounted in correspondence with one of the ends of the said structure (A, Al).

Going further into detail, the rotating tool-holder structure (A) is made up mainly of two semi-casings (3, 4), preferably in plastics, which form a 10 cylvidrical drum when joined together. Each semi-casing (3, 4) is made so as to be joined and held together with the opposite semi-casing, since at least one (4) of the two (3, 4) has a series of seats (41) that are used by means of screws (not shown) which pass through corresponding holes (31) formed in the opposite semi-casing (3). To make the joining of the two 15 semi-casings (3, 4) easier, the edges of each of the semi-casings (3, 4) may be of a particular form, for example with a toothed profile on one side that fits into corresponding seats in the opposite semi-casing. Furthermore, in order to safeguard the equipment inside the drum, a seal may also be used around the perimeter.

Each semi-casing (3, 4) has a particular conformation at the ends which, when joined together to form the drum, allows the small shafts (1, 11) and the equipment attached to them, such as bearings to improve the rotation of the assembly, to be mounted firmly in position. For example, 25 there are semicircular (411) seats in the semi-casing (4), that fit into similar seats in the opposite semi-casing (3).

The semi-casings(3, 4) also have a series of preferably equidistant openings (32, 42) in the form of slits. The formation of the said slits (32, 30 42) depends on the internal formation of the drum for the tools (7), and they may be either parallel to the rotation axis W of the rotating structure, or arranged according to a helix pattern, the preferred solution proposed by this invention.

9 5 At the side of each slit (32, 42) on the inside of each semi-casing (3, 4), for example for the lower semi-casing (4), there is a ring-form orifice (43). This solution foresees a number of orifices (43) positioned close to the slits (32, 42), following the helix pattern of the slits. In this way, a discontinuous seat is formed into which a preferably flexible cable (6) is 10 inserted co-axially. The said cable (6) in each semi-casing (3, 4) may be inserted in one direction only through the orifices (43), and is then fixed in position against shoulders formed in the corresponding structure of the semi-casing (3, 4). An alternative solution, foresees that the ends (61, 62) may be clamped along the inside of the corresponding emi-casing (3, 4), 15 for example with fixing means that clamp the ends against the structure of the semi-casing (3, 4).

The aim of the said cable (6) fastened in this way to each semi-casing (3,

4) is to hold a series of tools (7). Each tool (7) is made up of metallic 20 wire bent into a spiral shape similar to a spring (71). One end (72) of the spring-type piece (71), which forms the tooth, is straightened and in a radial position with respect to the rotation axis (x) of the structure (A) , while the spring part (71) is fastened to the cable (6), which is inserted co-axially to produce a torsion effect. The opposite end (73) of the 25 spring-type part (71) is also straightened, but while it is pressed against the inside of its relative semi-casing (3, 4), the tooth end (72) crosses through the relative semi-casing (3, 4) and passes in the corresponding slit (32, 42), so that when the tooth end (72) is activated, it is contrasted by the opposite end (73).

A variation of the solution described above is a rotating structure (Al) with a different system for fixing the tools (7) to the relative semicasing (3, 4). In particular, the spring-type part (71) of each tool (7), fits along the inside of its respective semi-casing (3, 4) and is held in position 35 against the surface by a removable axle (5). The axle is basically made up to 5 of a cylindrical body (5) with the peripheral surface that presses the tools (7) against the inside of each semi-casing (3, 4), obliging the ends (72) that pass through the slits (32, 42) to remain stretched towards the outside.

11

Claims

5 CLAIMS

1. Rotating support structure for a set of tools adapted to be applied to a motorised rake, comprising two semi-casings joined together to form a body that extends longitudinally of a rotation axis of the structure and 10 from which a tooth-end of at least one tool projects.

2. Rotating support structure according to claim 1, wherein each semicasing is concave and has tools fixed internally thereof tooth-shaped ends of which pass through the semi-casing and projeci to the exterior of 15 the semi-casing.

3. Rotating support structure according to claim 2, wherein the tools are fixed to the inside of each semi-casing by means of at least one removable axle.

4. Rotating support structure according to claim 2 or claim 3, wherein the semi-casings are made up of concave bodies, which have: seats into which the tools fit formed along the inside of each semicasing; 25 - a series of slits through which the tooth-shaped ends of the tools pass; means joining the semi-casings together to form a single, assembled tool-holder body; and ends whereby the semi-casings are supported on a frame of a 30 machine for use, and connected with transmission mechanisms and a motor.

5. Rotating support structure according to any preceding claim, wherein at least one tool is made up of metallic wire bent in a spiral 35 shape to form a spring-type body, with a tooth-shaped end projecting 5 from at least one of the semi-casings, and a second end fastened to one of the semi-casings.

6. Rotating support structure according to claim 5 as dependent from claims 3 and 4, wherein the tooth-shaped end of the spring-shaped body 10 passes through a corresponding slit in a respective one of the semicasings and extends to the exterior of the semi-casing, while the springtype body is fixed by the removable axle and the second end of the springtype body is held against the inside of the respective semi-casing.

15 7. Rotating support structure according to claim 4 or either of claims 5 and 6 as dependent from claim 4, wherein the series of slits is arranged in a helica I pattern around the part of the body extending longitudinally with respect to the rotation axis.

20 8. Rotating support structure according to claim 4 as dependent from claim 3, or claim 6, or claims 3 and 7, wherein the inside surface of each semi-casing has seats to hold the removable axle and the seats have at least one ring-shaped orifice to the side of the slits.

25 9. Rotating support structure according to claim 3, any of claims 4, 5 and 7 as dependent from claim 3, claim 6 or claim 8, wherein the removable axle is a flexible cable fixed with its ends along the inside surface of the respective semi-casing and which, by passing through at least one ring, supports the tools.

10. Rotating support structure according to claim 3, or any of claims 4, 5 and 7 as dependent from claim 3, claim 6 or claim 8, wherein the removable axle is made up of at least one body with an opposite section with respect to the internal profile of the part of the body which is 5 longitudinal with respect to the rotation axis, and is positioned inside the part of the body.

11. Rotating support structure according to claim 4, and any of claims 5, 9 or 10 as dependent from claim 4, or any of claims 6 to 8, wherein, at 10 the ends of the body formed by the joined semi-casings, shafts are attached to support the body of a frame or shell of apparatus with which the structure is used, and at least one end has a transmission mechanism.

12. Motorised rake comprising:

15 - a motor; a rotating cylindrical body on an axis that is parallel to the ground, that supports a group of tools, with each tool being made up of a spring with at least one tooth that projects from the rotating cylindrical body; transmission mechanism between the motor and the rotating cylindrical body; a guide handle for the operator; wheels to move the apparatus along the ground; controls for starting and stopping the apparatus and, if foreseen, controls for regulating the motor and mechanisms to regulate the working 25 height of the tools; if foreseen, a system to collect the material removed by the apparatus, and wherein the body comprises at least two concave semi casings joined together.

30 13. Motorised rake according to claim 12, wherein the concave semicasings together form a cylindrical drum from which tooth-shaped ends of the tools project.

5 14. Motorised rake according to claim 13, wherein the tooth-shaped end of each tool is straightened and extends radially with respect to the rotation axis of the body.

15. Rotating structure for a set of teeth adapted to be applied to a 10 motorised rake, substantially as described herein with references to the accompanying drawings.