GB2112613A

GB2112613A - Improvements in or relating to tine assemblies and components therefor

Info

Publication number: GB2112613A
Application number: GB08236612A
Authority: GB
Inventors: Alan Trelford
Original assignee: Black and Decker Inc
Current assignee: Black and Decker Inc
Priority date: 1982-01-06
Filing date: 1982-12-23
Publication date: 1983-07-27
Also published as: GB2112613B

Abstract

A component for the tine assembly of a lawn scarifier comprises a one-piece plastics moulding comprising a central boss (4) from which extend three tine arms (1, 2, 3). Each tine arm has a root (6) from which the arm extends in a radial direction for a short distance then follows a semi-circular path (9) and a straight radially extending portion that terminates in a hook (11). The configuration enables the tine arms (1, 2, 3) to flex readily over the semi-circular portion. The bosses (4) have faces that allow the components to be built up into a fine assembly. Mating surfaces on the bosses (4) are slightly offset to produce a spiral arrangement of the tine arms. <IMAGE>

Description

SPECIFICATION Improvements in or relating to tine assemblies and components therefor This invention relates to tine assemblies and components therefor and has particular although not exclusive reference to tine assemblies for use in machines for the treatment of grassed areas, for example lawns.

European Patent Specification No.

0024696 describes a turf scarifier having a tine assembly comprising a plurality of coil springs located either on helically disposed rods or in the pocketed recesses in a plurality of discs mounted upon a common driving axle. Both of those forms of tine assembly involve the fabrication and assembly of many components and this adds considerably to the cost of the assembly.

It is an object of the present invention to provide a tine assembly having fewer parts and which is cheaper to assemble than the construction just referred to.

According to the present invention, a component for a tine assembly comprises several resilient tine arms that extend from and are integral with a boss portion common to the arms.

Preferably, each arm has, remote from the boss, an end portion of hook-like form.

Each arm may be so contoured that it is able to flex over a portion of its length between the boss and the hook portion.

In one embodiment of the invention, each arm has a portion that extends radially from the boss, the radial portion leading into a portion of semi-circular form that is followed by a substantially straight portion at whose distal end is the hook portion.

Preferably, the component is of a plastics material.

Three equi-spaced arms are normally adequate but two may be found satisfactory as may be four or more.

By the way of example only, a tine assembly embodying the invention and a lawn scarifier including the tine assembly will now be described in greater detail with reference to the accompanying drawings of which: Figure 1 is a side elevation of a component of the tine assembly, Figure 2 is a front elevation of the component, Figures 3 and 4 are scrap side elevations of the centre faces of the tine assembly, Figures 5 and 6 are schematics of alternative forms of tine assembly, Figures 7 and 8 are, respectively, perspective and side views partly in section of the lawn scarifier.

The component of the tine assembly shown in Figs. 1 and 2 is a single piece moulding of a plastics material, for example acetal, and consists of three tine arms 1, 2, 3 that extend symmetrically from a common boss 4 of generally cylindrical form with a longitudinal bore 5.

Each tine arm has a root 6 that extends from the curved surface of the boss 4 and is located slightly closer to one end face 7 of the boss than the other end face 8. From its root 6, each tine arm projects for a short distance from the boss in a generally radial direction after which the member has a portion 9 of semi-circular curvature followed by a substantially straight radially-extending portion 1 0a that terminates in a "hook" 10 with an end edge 11 and a tip 12.

When viewed in side elevation, as in Fig. 1, it will be observed that the thickness of the arm is at a maximum at the root 6 and over the initial part of the semi-circular portion 9, then reduces over the remainder of portion 9 to a constant value over the straight portion 1 0a. The width of the hook 10 is substantially greater than that of portion 1 Oa but decreases towards the tip 1 2.

When viewed in front elevation, as in Fig.

2, the arm is of a width that decreases in a regular manner from the root 6 to the hook 10, the width of the latter being constant.

The end edge 11 of each hook 10 is not tangential to a circle 1 3 inscribed about the axis of bore 5 but is inclined somewhat to the tangent.

The three tine arms 1, 2, 3 of the component shown in Figs. 1 and 2 each extend over about 90 of arc as can be seen from Fig. 1, the roots 6 being, of course, equi-spaced round the circumference of the boss 4.

The configuration just described enables the arm to flex readily over the portion 1 Oa in a manner that enables the hook 10 to move towards and away from the boss 4.

The end faces 7, 8 of the boss 4 are castellated, there being three equi-sized, axially extending castellations 1 4 separated by equal gaps 1 5 on each face. The castellations 1 4 on face 8 are rotated with respect to gaps on face 7 by 6" about the longitudinal axis of the bore 5. The relative position of the castellations on faces 7 and 8 is shown clearly in Figs. 3 and 4, those on face 8 being advanced by angle A-in the present example this angle A being 6 .

The component shown in Figs. 1 and 2 forms one of about 20 mounted upon a common axle to form a tine assembly shown in Figs. 5 and 6 and suitable for use in the lawn scarifier shown in Figs. 7 and 8.

The components are located between end discs D1, D2 (Fig. 7) through which the axle also passes, the end discs being in driven engagement with end portions of the axle that are of square transverse cross section. When mounted upon the axle, the end faces of adjacent components are rotationally engaged via the spaced castellation whilst the end faces of the end components engage corre sponding formations on the faces of the end discs. The rotational offset of the castellations referred to above produces a spiralling of the tine members along the length of the axle.

The interlocking of the end faces ensures rotation of the components with the axle.

Fig. 6 shows a schematic of an assembly in which adjacent components have a 6" offset.

in Fig. 6, the tines of the various components are indicated by small circles referenced with the numbers 1, 2 and 3 of the tine arms. It will be appreciated that Fig. 6 is not a true side elevation but shows in two-dimensional form the entire surface of the tine assembly.

With the arrangement shown in Fig. 6, three spirals of tine arms are produced the rows being spaced by 120 .

Fig. 7 shows, in a manner similar to that of Fig. 6, an alternative tine assembly in which adjacent components have a 66 offset. That offset is produced by the 6" angle A to which is added a 60 rotation of the entire component relatively to the preceding component in the tine assembly. Again, in Fig. 6, the tine arms are referenced 1, 2 and 3 and it will be observed that a "double spiral" formation is produced. This distributes the load represented by the tines of the individual components and their action when in use more evenly over the 360" surface of the assembly.

The lawn scarifier shown in Figs. 7 and 8 includes a housing 1 6 which may be of metal or of a plastics material and has side walls 1 7 and a top wall 18. The top wall 18 has handle mounting means 1 9 at each side to which the limbs of a bifurcated handle 20 are pivotally attached.

The housing 1 6 is mounted for movement on wheels 21 at its forward end and a roller 22 at its rear end.

At its forward end, housing 1 6 has a large rectangular opening 23 in which the tine assembly referred to above and designated in Fig. 7 by reference 24 is mounted. For the sake of clarity only, two tine assemblies are shown, the spiralling of the assemblies along the length of the axle being indicated by the dotted line 24a. The tine assembly 24 is of the construction described above with reference to Fig. 5.

Secured to the forward end of the top wall 1 8 of the housing 1 6 are retainers 25 by means of which a grass or debris box 26 can be attached to the housing 1 6. The box 26 has hook-like extensions 27 which engage the retainers 25 to hold the box 26 in position on the housing. The box is otherwise of conventional form and will not be described further.

The tine assembly 24 includes a mounting axle 28 mounted at each end in bearings carried by the side wall 1 7 and one of which referenced 29 is visible in Fig. 7. The axle 28 is driven by an electric motor located beneath the top wall 1 8 and with an output shaft carrying a drive gear 30 coupled by a driving belt 32 to a driven gear 33 secured to the axle 28. The gears 31 and 33 and the belt 32 are located within a cover 34 secured to one of the side walls 17 of the housing 16.

The motor is powered via a power lead 35 carried by the handle 20, energisation being controlled by a switch located in a pistol extension 36 of the handle 20 and operated by a trigger 37. The lead 35 terminates in a connector 38 by which the lead is joined to a mains supply of electricity.

Adjustment of the vertical height of the tine assembly 24 relative to the ground is achieved by altering the vertical position of the roller 22 in the housing 1 6. For example, the roller 22 may be mounted upon a spindle carried between adjustable mounting means attached to the side walls 1 7.

Having set the roller 22 to a required height, the driving motor is energised via the control switch and the scarifier moved across a grassed area in a manner similar to a lawn mower. The hooks 10 of the tine members rake the grass so scarifying the same and removing dead mat moss and other surface debris, for example leaves and twigs, which is projected into the box 26. The hooks 10 also lift the stolons of creeping grasses and weeds so that these can be cut short during a subsequent mowing.

Should the tine arms encounter any irregularities or other obstacles in the surface, they are able readily to flex thereby avoiding being damaged by such irregularities or obstacles.

After use, debris left clinging to the tine members is easily removed and discarded.

If it is found that damage has occured to one of the components, it is a comparatively easy operation to remove the tine assembly and remove the damaged component by sliding it off the axle and fitting a replacement component. Such an operation can readily be carried out by the user.

CLAI IMS 1. A component for a tine assembly comprising several tine arms resilient at least in part that extend from and are integral with a boss portion common to the arms.

2. A component as claimed in claim 1 in which each arm has, remote from the boss, an end portion of hook-like form.

3. A component as claimed in claim 2 in which each tine arm is able to flex over a portion of its length between the boss and the end portion.

4. A component as claimed in claim 2 or 3 in which each tine arm has a first portion that extends radially from the boss and that leads into a second portion of semi-circular form, the second portion leading into a substantially straight radially extending third portion, the end portion being at the distal end of the third portion.

5. A component as claimed in any one of

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. sponding formations on the faces of the end discs. The rotational offset of the castellations referred to above produces a spiralling of the tine members along the length of the axle. The interlocking of the end faces ensures rotation of the components with the axle. Fig. 6 shows a schematic of an assembly in which adjacent components have a 6" offset. in Fig. 6, the tines of the various components are indicated by small circles referenced with the numbers 1, 2 and 3 of the tine arms. It will be appreciated that Fig. 6 is not a true side elevation but shows in two-dimensional form the entire surface of the tine assembly. With the arrangement shown in Fig. 6, three spirals of tine arms are produced the rows being spaced by 120 . Fig. 7 shows, in a manner similar to that of Fig. 6, an alternative tine assembly in which adjacent components have a 66 offset. That offset is produced by the 6" angle A to which is added a 60 rotation of the entire component relatively to the preceding component in the tine assembly. Again, in Fig. 6, the tine arms are referenced 1, 2 and 3 and it will be observed that a "double spiral" formation is produced. This distributes the load represented by the tines of the individual components and their action when in use more evenly over the 360" surface of the assembly. The lawn scarifier shown in Figs. 7 and 8 includes a housing 1 6 which may be of metal or of a plastics material and has side walls 1 7 and a top wall 18. The top wall 18 has handle mounting means 1 9 at each side to which the limbs of a bifurcated handle 20 are pivotally attached. The housing 1 6 is mounted for movement on wheels 21 at its forward end and a roller 22 at its rear end. At its forward end, housing 1 6 has a large rectangular opening 23 in which the tine assembly referred to above and designated in Fig. 7 by reference 24 is mounted. For the sake of clarity only, two tine assemblies are shown, the spiralling of the assemblies along the length of the axle being indicated by the dotted line 24a. The tine assembly 24 is of the construction described above with reference to Fig. 5. Secured to the forward end of the top wall 1 8 of the housing 1 6 are retainers 25 by means of which a grass or debris box 26 can be attached to the housing 1 6. The box 26 has hook-like extensions 27 which engage the retainers 25 to hold the box 26 in position on the housing. The box is otherwise of conventional form and will not be described further. The tine assembly 24 includes a mounting axle 28 mounted at each end in bearings carried by the side wall 1 7 and one of which referenced 29 is visible in Fig. 7. The axle 28 is driven by an electric motor located beneath the top wall 1 8 and with an output shaft carrying a drive gear 30 coupled by a driving belt 32 to a driven gear 33 secured to the axle 28. The gears 31 and 33 and the belt 32 are located within a cover 34 secured to one of the side walls 17 of the housing 16. The motor is powered via a power lead 35 carried by the handle 20, energisation being controlled by a switch located in a pistol extension 36 of the handle 20 and operated by a trigger 37. The lead 35 terminates in a connector 38 by which the lead is joined to a mains supply of electricity. Adjustment of the vertical height of the tine assembly 24 relative to the ground is achieved by altering the vertical position of the roller 22 in the housing 1 6. For example, the roller 22 may be mounted upon a spindle carried between adjustable mounting means attached to the side walls 1 7. Having set the roller 22 to a required height, the driving motor is energised via the control switch and the scarifier moved across a grassed area in a manner similar to a lawn mower. The hooks 10 of the tine members rake the grass so scarifying the same and removing dead mat moss and other surface debris, for example leaves and twigs, which is projected into the box 26. The hooks 10 also lift the stolons of creeping grasses and weeds so that these can be cut short during a subsequent mowing. Should the tine arms encounter any irregularities or other obstacles in the surface, they are able readily to flex thereby avoiding being damaged by such irregularities or obstacles. After use, debris left clinging to the tine members is easily removed and discarded. If it is found that damage has occured to one of the components, it is a comparatively easy operation to remove the tine assembly and remove the damaged component by sliding it off the axle and fitting a replacement component. Such an operation can readily be carried out by the user. CLAI IMS

1. A component for a tine assembly comprising several tine arms resilient at least in part that extend from and are integral with a boss portion common to the arms.

5. A component as claimed in any one of

the preceding claims in which the boss has a central axial bore and in which the boss has a first end face with equi-spaced, axially-extending castellations, and a second end face with an equal number of similar equi-spaced castellations so arranged that the end faces are able to be engaged in rotational driving relationship with the end face of adjacent components when mounted upon a common driving axle.

6. A component as claimed in claim 1 in which the castellations on one end face are displaced circumferentially about the axis of the bore with respect to those on the other end face.

7. A component as claimed in claim 6 in which the circumferential displacement is 6 .

8. A tine assembly comprising a plurality of components as claimed in claim 5, 6 or 7 mounted on a common axle passing through the bores of the components, the castellations on the adjacent end faces of adjoining components being engaged in rotational driving relationship.

9. A tine assembly as claimed in claim 8 in which the components are coupled to the common axle for rotation therewith by end discs rotationally coupled to both axle and an adjoining component.

1 0. A component as claimed in any one of claims 1-7 or an assembly as claimed in claim 8 or 9 in which the component is of a moulded plastics material.

11. A lawn scarifier including a tine assembly as claimed in claim 8 or 9.

1 2. A. component substantially as described herein with reference to and as illustrated by Fig. 1-4 of the accompanying drawings.

1 3. A tine assembly substantially as described herein with reference to and as illustrated by Figs. 1-4 and Fig. 5 or Fig. 6 of the accompanying drawings.

1 4. A lawn mower substantially as described herein with reference to and as illustrated by Figs. 1-4 and Figs. 7 and 8 and Fig. 5 or 6 of the accompanying drawings.