AU648210B2 - Combination blade for lawn edger - Google Patents

Description

S F Ref: 226483

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

48 "I ICL- C-~ Name and Address of Applicant: Willmark Pty Limited Elcho Street Hamilton New South Wales 2303

AUSTRALIA

Actual Inventor(s): Address for Service: Invention Title: Mark Clyde Collingridge Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Combination Blade for Lawn Edger ASSOCIATED PROVISIONAL APPLICATION DETAILS [311 Application No(s) [33] Country PL0334 AU [32] Application Date 9 January 1992 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5815/4 -2- COMBINATION BLADE FOR LAWN EDGER FIELD OF THE INVENTION The following invention relates to a combination blade for a lawn edger. More particularly, though not exclusively, the invention relates to a rotational blade assembly for attachment to a rotational shaft of a lawn edging apparatus.

PRIOR ART Known blades for use on lawn edgers comprise an elongate straight metal strip having a centrally located hole by which the blade is mounted to a shaft. As such blades are straight, the edge trimmer must be tilted for recess edging.

A further problem with such known blades is that where one end of the blade is damaged or where the blade has generally worn, the whole unit must be replaced and removed from the shaft of the edge trimming device.

OBJECT OF THE INVENTION It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages.

DISCLOSURE OF THE INVENTION There is disclosed herein a blade assembly for a lawn edger, comprising: a base member adapted to be received by, so as to rotate with a rotationally driven shaft of the lawn edger, the base member comprising a pair of blade attachment regions, 25 a pair of blade members, each being adapted to be received by the base member by engagement with a respective attachment region, and wherein either each blade member or each blade attachment region is provided with a pair of opposed channels into which the other of the respective blade attachment region or the respective blade member may be fixedly received.

Preferably, the blade members extend from the base member i- an obtuse angle thereto.

Preferably, each blade member is adapted to be secured to the base member by way of a fastener extending through a hole in the base member S 35 and the respective blade members.

Preferably, the fastener is a stud, the stud being held in position by way of a pin.

RF/29741 3 BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: Fig. 1 is a schematic elevational view of a one piece blade member, shown for reference only, Fig. 2 is a schematic plan view of the blade member of Fig. 1, Fig. 3 is a schematic elF *ational view of the blade member of Fig. 1 attached to a drive member of a lawn edger, Fig. 4 is a schematic elevational view of a blade assembly in accordance with a preferred embodiment of the invention, Fig. 5 is a schematic plan view of the assembly of Fig. 4, Fig. 6 is a schematic plan view of a base member forming part of the embodiment of Figs. 4 and Fig. 7 is a schematic plan view of the blade members of the embodiment Fig.

Fig. 7, of Figs. 4 and 8 is a schematic elevational view of the blade members of Fig. 9 is a schematic elevational view of an alternative pair of blade members to that depicted in Fig. 8, Fig. 10 is a schematic representation of a clevis pin adapted to attach the blade members of Figs. 7, 8 and 9 to the base plate of Fig. 6, Fig. 11 is a schematic representation of the hunch back and clevis pin of Fig. Fig. 12 is a schematic elevational view of a blade assembly in accordance with a third embodiment of the invention, 25 Fig. 13 is a schematic plan view of a blade member of the third embodiment, and Fig. 14 is a schematic elevational view of the blade of Fig. 13.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In Figs. 1 and 2 of the accompanying drawings there is schematically depicted a blade 22, being generally elongate and comprising a base portion 23 and cutting portions 24 each expindin( from the base portion at an obtuse angle with respect thereto. A hole 14 extends through base portion 23. A shaft 21 of an edge trimmer extends through hole 14. The blade assembly is held in place on shaft 21 by way of a nut Rather than forming the blade as an integral unit, an alternative embodiment as depicted in Figs. 4 to 8 comprises a base plate 11 having hole 14 extending centrally therethrough. At opposing ends of plate 11 A. is a hole 15 to be described below.

l. RLF/29741 -4- Adapted to be received at opposing ends of base plate 11 is a pair of blade members 12, 13. At the proximal end of each blade 12, 13 a pair of opposing channels 16 is fotrmed. As the blades 12, 13 are typically formed of spring steel or other suitable steel sheet, channels 16 may be formed by folding the blade material as required, thus producing a step 18. Blades 12, 13 may be slidably engaged with base plate 11 via channels 16 such that a hole 17 through a respective blade 12, 13 aligns with a respective one of the holes 15 in base plate 11. Through these aligned holes a stud 19 may be inserted and held in position by way of pin 18.

In the embodiment depicted in Figs. 5 to 8, the blade cutting portion 12, 13 extends at an obtuse angle with respect to base plate 11.

Similarly, in Figs. 2 and 3 the integrally formed embodiment of the invention comprises angularly offset regions. By comparison, the embodiment depicted in Fig. 9 comprises no obtuse offset and as such, blades 13 extend in a common plane with base plate 11.

In use of the apparatus depicted in Figs. 1 to 8, 10 and 11 the blade assembly 10 or unitary blade 22, no tilting of an edge trimmer is required for recess edging. In the embodiment depicted in Figs. 4 to 8, one of blades 12 may be reversed so as to enable the assembly to be utilised in the trenching of lawns.

Should a blade become worn or damaged, it is not necessary that the base plate 11 be detached from the edge trimmer. Rather, the hunch back and clevis pins may simply be removed so as to allow convenient refitting of a new blade 12, 13.

In Fig. 12 there is schematically depicted an alternative combination blade assembly. The alternative blade assembly comprises a base plate 25 having a pair of channels 26 formed at each opposing end.

In this embodiment, blades 27, being the parts likely to wear, would be less expensive to produce and replace since channels 26 are provided on base plate 25. Like the first and second embodiments, the blades 27 are provided with an obtuse angled end portion. Blades 27 may be affixed by any convenient means such as split pin, hunch back pin or clevis pin or the like. Nuts and bolts for example may also be adopted.

35 It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention. For example, the specific arrangement of channels 16 depicted in Fig. 7 may be replaced by any convenient means of interengaging blades 12, 13 with base plate 11.

LRLF/29741

Claims (5)

1. A blade assembly for a lawn edger, comprising: a base member adapted to be received by, so as to rotate with a rotationally driven shaft of the lawn edger, the base member comprising a pair of blade attachment regions, a pair of blade members, each being adapted to be received by the base member by engagement with a respective attachment region, and wherein either each blade member or each blade attachment region is provided with a pair of opposed channels into which the other of the respective blade attachment region or the respective blade member may be fixedly received.

2. The blhde assembly of claim 1 wherein the blade members extend from the base membt; at an obtuse angle thereto.

3. The blade assembly of claim 1 or claim 2 wherein each blade member is adapted to be secured to the base member by way of a fastener extending through a hole in the base member and the respective blade members.

4. The blade assembly of claim 3 wherein the fastener is a stud, the stud being held in position by way of a pin.

5. A blade assembly substantially as hereinbefore described with reference to Figs. 4 to 14 of the accompanying drawings. DATED this FIRST day of SEPTEMBER 1993 NWillmark Pty Limited Patent Attorneys for the Applicant SPRUSON FERGUSON 0 *oo «o~ RLF/29741 f COMBINATION BLADE FOR LAWN EDGER ABSTRACT OF THE DISCLOSURE A blade assembly comprises a base plate 25 adapted to be secured at hole 14 to a rotationally driven shaft of a lawn edging device. Base plate 25 comprises a pair of slots 26 at each end to receive a blade 27 having an obtusely angled end portion. The obtuse angle of the blade provides a convenient means by which the edge trimmer may be utilised for recess edging without tilting. Figs. 12 and 14 0 **ee o e **e heC C. S C b 6 oe *4 0 go TMS/STA/29741