AU616690B2 - Improvements relating to a grass or scrub snipper - Google Patents

Description

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f Form COMMONWEA6.TH OF AUSTRA6 PATENTS ACT 1952-9 6 1 669 0 COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Applicationl Number, Lodged: *ComplIete Specificatior Lodged: **SS Accepted: Published: *Priority: .6 0 *00 Name of Applicant: Addtress of Applicant: Actual Inventor: Address for Service MARIA ROSA CALCIINAI via Molino No. 18, Montaniono Fraz. Comune Reggelo, Firenze, Italy.

MARIA ROSA CALCINAI EDWD. WAFERS SONS, 50 QUEEN STREET, MELBOURNE, AUSTRALIA, 3000.

Complete Specification for the invention entitled: IMPROVEMENTS RELATING TO A GRASS OR SCRUB SNIPPER The following statement is a full description of this invention, including the best method of performing it known to: me -12 6. An appliance in accordance with claim 1, comprising profiles cooperating in the intermediate component and the casina for startina UD rotation of the 9

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DESCRIPTION

The invention concerns an appliance for scrub clearance, grass cutting and the Like, with multiple Lines as cutting elements, comprising a casing and, inside said housing, at Least one spool on which said Lines are wound, it being possible to increase the Length of said Lines in terms of the type of vegetation to be cut or to restore said Lines to their previous Length foLLowing operational wear.

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06 See a 0 0O S 0 ae 55 a 0 S.r *h 5 5 In appliances of this kind, regulating and/or restoring the Length of tne cutting Lines is often a Long ana tedious operation. In some types of known appliances, in fact, the casing in wnich the spools with the Line are housed has to be unscrewed and partially opened, each Line Lengthened by the action of pulling on its free end, and 15 the casing closed again. Apart from the obvious disadvantage of having to partially open the casinn housing the spools of Line, the lengths of cutting Line obtained in this way are never completely uniform.

Appliances are also known, for example from 20 US-A-4,107,901, which are provided with a rather complex device for automatic paying out of the cutting Line, comprising a solenoid and a driving mechanism which puts a spool of cutting Line into rotation in order to unwind a predetermined Length of Line.

Appliances also exist which have 'nside them multiple spools of cutting Line, four for example, each of which is attached to resilient Locking devices. To Lengthen each of the Lines an unlocking device is operated (usually a'push-button), serving the Line in question, and this causes release of the resilient Locking devices 30 and enables the Line to be unwound through the action of pulling on its free end. In appliances of this type, as many lengthening operations require to be performed as there are cutting lines. Moreover, in this case also,

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13 11. An appliance according to claim 9, wherein plug-in devices are housed in, ;nnr~,l ,.,ith tha tiihilar wall for mutual Pnnnnamnt nf the twn narts 2 the different lines are not lengthened to the same uniform Length. And furthermore, if multiple spools of cutting line are provided that are positioned off-center in relation to the axis of rotation of the casing, and if the amount of line wound on the different spools is not uniform, the appliance will be dynamically unbalanced and may start to vibrate when operated.

Grass-cutting, scrub-clearance and similar appliances are usually coupled at the end of a shaft handle to a hub that generally rotates on an axis at an obtuse angle to the axis of the shaft. The hub is generally designed with.a series of stepped circles enabling the positioning of the appliance to be rotated.; screw-type devices 0• are used for aff'ixture, which can be in .the '.orm of a S* 15 threaded pin on the hub in conjunction with a fastening nut on the appliance, or of a threaded hole for taking a bolt. In any case, the method of affixture employed calls for space in the center of the appliance for the nut-andbolt type fastening devices. US-A-4,097,991 discloses an 20 appliance of this type. This places a Limit on the 'i"I types of appliance that c.an'be affixed to a shaft handle of the aforementioned type. Scrub-clearance, grass-cutting S -and -similar appliances also present problems in regard-to the provision of affixture openings in the center of the appliance.

The subject of the invention is an appliance of the Stype described above which does not present the aforesaid disadvantages and which imposes no limitations on the type of grass-cutting, scrub-clearance or similar appliance that can be affixed to a hub affixed to a shaft handle of the type described above. Additionally, it is an object of the invention to provide an appliance wherein it is a very simple operation to engage in and release it from the hub of the drive shaft. It is a further object of an improved embodiment of the invention, to provide an appliance that r p i: ~If

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3enables the cutting lines to be unwound with ease and dispatch, with the lines being unwound to a uniform length.

The invention therefore provides an appliance for scrub clearance, grass cutting or the like, with multiple lines as cutting elements, comprising a casing, and inside said casing, at least one spool on which said lines are wound, it being possible to increase the length of said lines in terms of the type of vegetation to be cut or to restore said lines to their previous length following operational wear, said casing being designed to be coupled to the rotary hub fitted at the end of a shaft handle, characterised in that 10 said appliance including an intermediate component placed between the rotary hub and the casing and designed to be engaged with the rotary hub to rotate therewith, and quick release coupling means provided between said intermediate component and the casing of the appliance, to ensure that the casing is quickly releasable from said intermediate component without demounting the casing. Preferably, the intermediate component is bowlshaped.

Conveniently, the intermediate component is fitted with coupling slots and the casing of the appliance with resilient attachments engaging in said slots; quick release coupling being effected with the use of engaging pieces provided n said attachments, release being obtained by means of pressure on the resilient attachments.

The intermediate component can have an aperture for fitting onto a stepped pickup provided in the usual manner on the rotary hub, the intermediate component being firmly affixed opposite this pickup by screw device is to the hub. A reducing ring can be used to function between the aperture in the component and the stepped pickup, if the latter has reduced dimension.

The appliance can also have profiles co-operating in the intermediate component and the casing of the appliance for starting up rotation of the appliance.

In an improved embodiment, the appliance according to the invention comprises: devices for coupling and uncoupling said two parats; resilient devices designed to mati,.ain said coupling devices in the hold position; and, of one piece with one of said two parts, devices for effecting connection between said part and said spool, whilst the other one of said parts exhibits outlet bushes for the ends of the lines.

o4Lb97 2~ Fig. 1 .Fi9.1 97 I 93 93 f Fiq.2 00 a 0 0*0 -4 In a1tictai re~iL ienc devices urge said Paris Com~rOS eicfl othe~r in Cne 3xiaL oireCtiOnA, Ene QiS-CanCinG oi sa i r-o parts in r aL B io0n 1o e a Cn orflA r i n I n ZAiLL OirCCijof Causing Ina aisangageent oT Said coupana uncoupLing dewices. Wicn cnis System ir is pos- SiOLe for One Of Cne two parts of r neac ro e fleLa steady wniLsc I e ocner is moved away it, Ina axiaL d ir ection. Ina parts being cnw.s aisengaged, and for Ene Line ro be Enerewpon unwouno from tne Spoo~or spooLS Dy rOC3r)On 01 In& Eio ParC. in reLarion ro eacti ocner. In Enis way Ene operat ion of reguLating Ina Leng-.l of LineC is Mace SimpLe andl rapia. Wflen cte SPOOL, or one of Ina spooLs, is empty ic can oe speaciLy repLaced cnrougjn Ciserigagcmcri 01 c to parts formning mle hed In one possioLe casodiient, one of Said parts comtpriSeS a .uouLar waLL forming a grooved profiLe for coupLing on Ine SPOOL or POOL$ of Line, Ina SPOOL or spooLs of Line being sac TirmLy in Said mubutar waLL in mnar i-ime 7 1AaS/nav& a corresponding grooved profiLe for en~agealenr i n 4 4ic 0COULar waLL; said part is aLso equippad wictl a s riC ofsa prcruding pins in a frontal coupling device dCaSiineO to engage in matching noLes in Ina other of Ina Said parts forming Eme casing liowsing Ina SPOOL or spooLs.

Said rasiLienr oavi caS can aLso oe flowsed in-fle ri.bwLar waLL, ;s Can devices for cowpLing together thie two parts f onuing Ene casing or Ina appLiance. Said cowpLing devices are in Cnis way aLL n oused in the head, and consmimume no oostruclion Dccmeen me& hcaad and mne swriace c mne gr ounqd, To r A p Le a o ne workedoOver..

Tne drawings iLLwarrace one, non-Limiting, emflodixcenr of rrx.invencien. In thiese drawings: Fig. I represents AA- overaLL excernaL view of the appLiance coupLed to Ina end of a Shaft; fig. -5 represents a parciaL secrionaL view of Inae component and mne components operating in c onj.L ccmi on wi r n La m P '.7 594 /0 4

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-4a Fig. 3 represents a partiaL expLoded view; Figs. 4 and 5 iLLustrate a grass cutting appLiance us ing a L ine, f it ted with coupLing device's corresponding with sections IV-IV and V-V in Fig. 3; figs. 7 and 8 represent sectionaL views corresponding with sections VI-VI, VIl-VII and VIII-VIII in F ig. 4; Fig. 9 shows one of the casing parts in perspective; Fig. 10 iLLus.trates the grass cutter shown in sectionaC view in Fig. 4 with the component parts aLL disass emb Led.

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5 As shown by the drawings, the appliance comprises a casing formed of two parts 51 and 53 coupled together in such a manner that they can slide in the axial direction and also rotate.

The part 53 forms, with a cylindrical wall 65, a seating 67 that is coaxial with the head, closed at the inner end by an end wall 69 with a hole in the center for the sliding insertion of a corresponding cylindricaL wall 71 belonging to part 51, forming a housing seating for a bayonet joint. The seating 67 houses a plug component 73 and a compression spring 75 reacting between the end wall 69 and a flange 73A of the plug 73. To create the bayonet joint, the plug 73 forms a shaft 738 with two opposed radial pins 73C whilst a thickening 71A in the cylindrical wall 71 forms an axial guide seating for the shaft 738 with two grooves 718 for the pins 73C and two seats 71C in which the pins 73C are housed following rotation of the plug 73 through 900 after the pins 73C have slid through the grooves 71B. When the plug 73 is engaged in the seatings 71C of the wall 71 formed by the part 51, the two parts 51 and 53 are urged by the spring towards each other and maintained in the closed position when the plug 73 is engaged in a bayonet joint in the manner described above. It is to be noted that the plug 73 is fully recessed in the seating 67 of the part 53, and can be manipulated by virtue of an enlargement 67A of said seating 67.

The parts 51 and 53 form a front teeth coupling, with, in the example shown, pins 77A coming out of the end wall 69 and holes 778 in the part 51. In this way, when the plug 73 is engaged in a bayonet joint in the walL 71, the two parts 51, 53 must be parted in the axial direction overcoming the force of the spring 75 for the two parts 51, 53 to be released and rotated in relation to each other.

The cylindrical wall 65 exhibits on the outside a grooved profile 80 coupling with a corresponding grooved 6 profile on a spool 81 or a pair of spools 81, 83 whereon the cutting lines F are wound. Two Lines F can be wound on the spool or on each spool; the inside ends of the lines F are held fast in seatings in the spools, whilst the outside ends of the Lines F protrude from the casing formed by the two parts 51, 53 through apertures 85 A in bushes 85 housed in corresponding seatings 87 on the shell 51A of the part 51 of the head. To unwind the Lines F, and so lengthen them, all that is required is to grip the two parts 51, 53 and move them apart from each other in the axial direction against the force of the spring 75 so as to disengage the pin coupling 77A, 778; thereupon, keeping the two parts 51, 53 apart, it is possibLe to rotate them in relation to each other and hence, by reason of the grooved profile coupling between the part 53 and the spools 81, 83, cause the Latter to rotate in relation to the part 51 housing the bushes 85, thus causing the .ines F to unwind from the spools through the apertures S Using the method described, it is possible to unwind S in a single operation an equal Length of Line with respect I' S "to aLL the Lines F in use. It is not necessary to pull out the Line F manually through the apertures in the bushes .85. In effect, once the Line F has been sLackened foLLowing rotation of the two parts 51, 53 in relation to each other, the subsequent action of rotating the casing 51, 53 causes the slackened Lines F to protrude by the action of centrifugal force.

The bushes 85, with apertures 85A to aLLow the Lines F to pass through, are eLongated in shape and are housed in the corresponding eLongated seatings 87 on the sheLL 51A of the part 51 of the head. In this manner, even if the seating housing the bushes 85 becomes worn, and there is some play between seating and bush, the Latter will not come away from its respective seating when the two parts 51, 53 are moved apart for the Line to be unwound, but will merely slide within the seating, reverting to its P d j"I_

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5 *S 5 i i -I- 7 7original position when the two parts 51, 53 are recoupLed together. In this way, Loss of any of the bushes is avoided, as is the possibility of the dangerous consequences that could result if a bush 85 were to come away from its seating 87, since the bush could then be projected outwards by centrifugal force with start-up of rotation.

For changing the spools 81, 83 or any others, it suffices to free the plug 73 by pressing it against the action of the spring 75 so as to disengage the pins 73C from the seatings 71C, then turn it and withdraw it in such a manner that the pins 73C slide in the grooves 71B, thus causing the two parts 51, 53 to move apart from each other, and finally recouple them by carrying out the same operations in reverse.

A differing number of spools can also be set into the grooved profile 80 of the cylindrical wall 65, a single, taller spool, for example, or two or three separate spools. Spools can also be used with a single line winding or with windings comprising more than two lines, four lines, for example.

A scrub-clearance and grass-cutting appliance of the kind described, housed inside the casing formed by the two parts 51, 53, can be coupled to a rotary drive hub in the manner described below.

The numeral 91 in Figs. 1, 2 and 4 illustrates in summary form the shaft handle housing inside a drive shaft extending by means of an articulated joint to the head 93 of the shaft handle; from the head 93 there protrudes a hub 95 which is caused to rotate by the motor carried by the shaft handle 91, on an axis that is inclined in relation to that of the shaft handle. In particular, the hub 95 is in the form of a stopped circular component 95A serving to center and position the appliance to be affixed, which must for this purpose exhibit an aperture whose circular dimensions are no smaller than those of the cylindrical wall of the stepped component The method of affixture is through a screw 8 device, represented in the drawings by a bolt 97 for affixture in an axially positioned threaded hole in the hub 95, to couple to said hub an intermediate component 99 with an aperture for fitting over the stepped component 95A. In other possible embodiments, the hub has a threaded pin for coupling up the same wall with the aperture, by means of a nut.

The grass-cutting, scrub-clearance or similar appliance is housed inside the two parts 51, 53 described above. The appliance needs to be affixed to the hub to which it is coupled through the interpositioning of the said intermediate component 99, designed in the shape of a bowl. In particular, this intermediate component 99 displays a hole 99A in the center whose diameter corresponds with that of the cylindrical wall of the stepped component 95A or is greater than the diameter of said wall, in which case recourse must be had to a reducing element. The intermediate component 99 also has a rim 998 that can be employed as a support for the casing of the appliance. In all cases the intermediate component 99 has slots 100 positioned laterally in a uniform arr-

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angement round the axis of the component 99, which can for example comprise two opposed slots 100 in the sloping wall of the bowl-shaped intermediate component 99.

In correspondence with the slots 100, resilient attachments 112 are provided extending from the shell 51A of the part 51 of the appliance, comprising engaging pieces 112A and retaining edges 1128; corresponding with said attachments 112 are slots 51E in the part 51, to enable the attachments 112 to be resiliently displaced by flexure. The resilient attachments 112 are designed to be snap-inserted in the slots 100 through the sliding motion of the engaging pieces 112A forming part of said resilient attachments. Catch retention is effected between the retaining edges 1128 and the rims 100A of the slots 100 closest to the edge 998.

The bowl-shaped intermediate component 99 is aff-

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H 0 0 @044 0.0 0 7 -9 ixed by means of the screw devices 97 already indicated (or other means) to the stepped component 95A, the thickness of the said intermediate component 99 in the area of the hoLe 99A being not less than the height of the stepped component 95A. If the diameter of the cylindrical wall of the stepped circular component 95A is smaller than that of the hole 99A, reducing ring elements 114 can be employed (Fig. 2) whose external diameter corresponds with that of the hole 99A and whose internal diameter corresponds with that of the cylindrical wall of the stepped component 95A, with one or other of the rings being used in conjunction with the intermediate component 99 on the stepped component 95A; as a rule, one ring alone 114 is sufficient to compensate for the one difference in diameter that is to be found between two standardized diameters of the types of hub used for the coupling of the shafts that are the most widely sold.

The bowl-shaped intermediate component 99 is affixed to the hub 95 of the shaft handle 91 by being screwed on with the use of screw devices 97, with the interposition of a resilient shrinkage plate 97A. The appliance to be affixed and operated is coupled to the bowl-shaped component 99 by its own resilient attachments 112 with the aid of the engaging pieces 112A on said resilient attachments, which slide over the edge 998 and hence inside the component 99 till they mesh in with the teeth 1128 on the rims 100A of the slots. To release the appliance, all that is needed is to press down radially on the pieces 112A belonging to the resilient attachments 112, projecting in alignment with the slots 100, to cause the teeth 1128 to be released from the rims 100A. It is advantageous, for this operation, for the attachments 112 and the slots 100 to be in number of two and diametrically opposed.

For starting rotation of the appliance, direct use can be made of the attachments 112, but suitable pieces for 4 4 4 0 *0 4 *r 4 1. I axial engagement can be provided for purposes of startup, on attachments coming from the casing 51, 53 of the appliance, like those indicated by the numeral 116 in the drawings, to operate in conjunction with correspondingly shaped elements 118 inside the bowl-shaped intermediate component 99. Coupling arrangements for start-up involve the axial positioning of the casing 51, 53 of the appliance by means of the resilient attachments 112 for engagement in the slots 100, possibly also with the use of guide and connecting pieces for angular positioning of the said resilient attachments 112 in corres- S. pondence with the slots 100 and/or of guides for posi tioning the attachments 116 with respect to the profiles 118.

With this coupling system, the appliance to be affixed requires to have the resilient attachments 112, j which are on the periphery, and possibly the attachments for engagement and start-up indicated by 116, but no other Sspace-consuming coupling elements are necessary, especially in the central, that is to say, axial area of the appliance; accordingly, various different types of appliance I can be coupled to the shaft with the interposition of the i component 99.

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Claims (9)

1. An appliance for scrub clearance, grass cutting or the like, with multiple lines as cutting elements, comprising a casing, and inside said casing, at least one spool on which said lines are wound, it being possible to increase the length of said lines in terms of the type of vegetation to be cut or to restore said lines to their previous length following operational wear, said casing being designed to be coupled to the rotary hub fitted at the end of a shaft handle, characterised in that said appliance including an intermediate component placed between the rotary hub and the casing and designed to be engaged with the rotary hub to rotate therewith, and quick release coupling means provided between said intermediate component and the casing of the appliance, to ensure that the casing is quickly releasable from said intermediate component without demounting the casing. S. AS S 2. bowl shaped.

An appliance according to claim 1, wherein the intermediate component is

3. An appliance in accordance with claim 1 or 2, wherein the intermediate component is fitted with coupling slots and the casing with resilient attachments engaging in said slots; quick release coupling being effected with the use of engaging pieces provided on said attachments, and release being obtained by means of pressure on the resilient attachments.

4. An appliance in accordance with any one of claims i to 3, wherein theintermediate component has an aperture for fitting onto a stepped pickup provided on the rotary hub, the intermediate component being firmly affixed opposite this pickup by screw devices to the hub.

An appliance in accordance with claim 4, wherein a reducing ring is provided to iunction between the aperture in the intermediary component and the stepped pickup, if the latter has a reduced dimension. ia 12

6. An appliance in accordance with claim 1, comprising profiles co- operating in the intermediate component and the casing for starting up rotation of the casing.

7. An appliance as claimed in one or more of the preceding claims, wherein the casing comprises, two parts coupled together; devices for coupling and uncoupling said two partas; resilient devices designed to maintain said coupling devices in a position to hold the two parL3s together; and -e*"***integral with one of said two parts, devices for effecting connection between said one part and said spool whilst the other one of said parts exhibits outlet S.bushes for the ends of the lines.

8. An appliance in accordance with claim 7, wherein said resilient devices urge said two parts of the casing towards each other in the axial direction, the distancing "of said two parts in relation to each other in the axial direction causing the disengagement of said coupling and uncoupling devices.

9. An appliance in accordance with claim 8, wherein one of said two parts of the casing includes a tubular wall forming a grooved profile for coupling on the spool or I spools of line, the spool or spools of line being set firmly in said tubular wall; and wherein said part is equipped with a series of protruding pins of a frontal coupling device, designed to engage in corresponding holes in the other one of said two parts forming the casing. An appliance in accordance with claim 9, wherein said resilient devices comprise a compression spring housed inside said tubular wall. U I~ i ir .9 9 0 *909 as rnere are cutting Lines. Moreover, in tnis case also, 13 1,1. An appliance according to claim 9, wherein plug-in devices are housed in, but not integral with, the tubular wall for mutual engagement of the two parts, especially in a bayonet joint. DATED this 9th day of August, 1991. MARIA ROSA CALCINAI WATERMARK PATENT TRADEMARK ATTORi'EYS 2ND FLOOR "THE ATRIUM" 290 BURWOOD ROAD HAWTHORN VIC. 3122 AUSTRALIUA