AU632983B2 - - Google Patents

Description

63298 P/00/012 Regulation 3.2

AUSTRALIA

Patents Act 1990 COM P L E T E S P EC I FI C AT ION 1 r FOR A PETTY PATENT

ORIGINAL

Name of Applicant: Actual Inventor(s): Address for Service: ROGER MARTIN HALL ROGER MARTIN HALL JOHN R.G. GARDNER REGISTERED PATENT ATTORNEY PO BOX 443 MUDGEERABA Q 4213 Attorney Code: i,, Invention Title: SPRING LOADING TOOL The following statement is a full description of this invention, including the best method of performing it known to me:- 9 2 Vi THIS INVENTION relates to a spring loading tool which is particularly but not exclusively suitable for loading starter springs into spring loaded starter mechanisms of the type used in small internal combustion engines, such as in engines for brush cutters, chain saws or lawn mowers.

i Starter mechanisms for small internal combustion engines commonly include a starter rope which is pulled by the user so as to cause cranking of the engine for starting purposes. Associated with the mechanism is a rewind spring which causes the starter motor cord to be rewound onto a spoc.

Such springs are normally spirally wound leaf springs supported within in a spring housing. Breakage of such springs necessitates disassembly of the starter mechanism and replacement of the spring. If maintenance work is being carried out on the starter mechanism, the spring often is detached from its housing. In each, case replacement of the spring and/or repositioning in the housing creates a number of difficulties. In particular winding of the spring into a spiral form such that it may be placed 'into its housing proves very difficult by hand. Often rewinding of a spring is not attempted and a prewound spring used instead.

'I The present invention aims to provide a tool which facilitates the loading of a spring into a spring housing 2 particularly a spirally wound spring into a housing of a 25 starter mechanism. The present invention also aims to provide a tool which facilitates the winding of a spring into a spiral form prior to its placement into a spring housing. Other "objects and advantages of the invention will become apparent from the following description.

30 The present invention thus provides a spring loading tool for loading a spring into a spring housing, said tool having a main outer body, a chamber within said body, piston means supported within said chamber and normally disposed adjacent one end of said chamber to define a spring receiving compartment therein, said piston means having means with which one end of said spring may engage, actuatinq means for said R piston means and operable to rotate said piston means so as to

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cause a spring engaged therewith to be wound up within said compartment into a spiral form, said actuating means being further operable to move said piston means longitudinally relative to said body so that a said spirally wound spring in said compartment may be displaced from said body and moved in its spiral configuration into said spring housing.

Suitably, the body includes an opening into the compartment through which a spring may pass upon rotation of the piston means. Preferably, the body is of cylindrical form and the actuating means comprises a handle connected to the piston means.

Preferably the piston means includes a disc-like member. Preferably the body includes an internal stop which, when the disc-like member is resting thereon defines within the chamber, the compartment into which the spring may be rewound and/or wound into its spiral form. The piston means preferably includes a central recess so as to accommodate a central boss on the spring housing when located therein. The outer body is preferably of an external diameter such as to allow for its neat receipt in the spring housing.

The spring engagement means on the piston means "suitably comprises a spigot or pin off-set from the recess so that upon rotation of the handle the spring may be wound up S into the compartment. Extending outwardly from the recess is 25 a bush or other tubular member or stop which prevents the spring moving over centre when being wound up within the compartment. A removable cap may be engaged over the end of 0: the body so as to facilitate winding up of the spring and 0.0 0 constrain the spring within the compartment.

30 In order that the invention may be more readily understood and put into practical effect, reference will now 0 be made to the accompanying drawings which illustrate a o preferred embodiment of the invention and wherein:- Fig. 1 is a perspective view showing the spring loading tool of the invention with a spring being wound therewith; Fig. 2 is a longitudinal sectional view of the tool of 3a Fig. 1 with the end cap applied; Fig. 3 is an end view of the tool of Fig. 1 showing a spring supported therein; Fig. 4 is an end view of a typical spring housing having a wound spring located therein; and Figs. 5 and 6 illustrate the manner in which the spring 4 S S* I 3 4 14 4

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I is loaded into the housing using the tool of the invention; Referring to the drawings and firstly to Figs. 1 and 2 there is illustrated a spring loading tool 10 according to the present invention, including an outer cylindrical body 11 !i 5 in which is supported for longitudinal movement a piston assembly 12 including a disc-like portion 13 sized for neat receipt within the body 11, the piston assembly 12 including a handle assembly 14 terminating in a gripping handle or knob The body 11 is provided in its side wall 16 at one end with a slot 17 through which a spring may pass as described further below. The piston assembly 12 is normally maintained in the attitude of Fig. 1 by means of a stop 18 which may be in the form of an annular flange upon which the disc-like Z portion 13 sits so as to define in the end of the body 11 15 adjacent the slot 17 a spring receiving compartment 19.

,I Arranged centrally within the piston assembly 12 and opening Kthrough the disc-like portion 13 is a blind bore 20 which is of a size to locate over and receive the upstanding boss 21 of a spring housing 22 (see Fig. 4) during loading of a spring 20 therein. Arranged co-axially with the bore 20 and extending outwardly from the disc-like portion 13 is a bush or other tubular member 23, whilst a spigot 24 of pin-like form is located radially outwardly of the bush 23 and adapted to receive one hooked end 25 of a spring 26. A cap 27 is provided for location over the outer end of the body 11, the cap 27 I having an annular skirt 28 provided with a slot 29 adapted to "tit, be aligned with the slot 17 in the side wall 16 of the body 11 when the cap 27 is engaged with the body 11.

In use, one end of the spring 26 is passed through the slot 17 in the body wall 16 and the end 25 hooked over the spigot 24. The cap 27 is then engaged with the body 11 in the manner shown in Fig. 2 so that the slot 29 therein is aligned with the slot 17. The handle 15 is then grasped and rotated in the direction of the arrow in Fig. 1 to rotate the piston assembly 12 whilst the body 11 is prevented from movement relative thereto, such as by grasping by hand, thereby causing the spring 26 to be wound up in a spiral fashion into the r compartment 19, the bush 23 during this procedure acting as a stop preventing the spring 26 from moving over-centre upon rotation of the piston assembly 12. This procedure is continued until the spring 26 is fully wound into its spiral form as shown in Fig. 3 with the opposite hooked end 30 of the spring 26 being disposed outwardly from, but adjacent to the body 11.

The cap 24 which during the above procedure assists in maintaining the spring 26 in a flat form within the compartment 19 may be then removed and the tool 10 aligned with the spring housing 22 as shown in Fig. 5 with the end 30 of the spring 26 longitudinally aligned with a receiving hook 31 within the housing 22. The tool 10 is inserted into the housing 22 as shown in Fig. 6 until the body 11 seats therein and so that the end 30 engages with the hook 31 as shown in Fig. 4. In this position the boss 21 locates within the bush 23 and bore 20 of the piston assembly 12. Pressure is then maintained on the handle assembly 14 so that the spring 26 is maintained in a flat attitude within the housing 22. The body 11 is then 20 retracted relative to the piston assembly 11 and housing 22 as shown in dotted outline in Fig. 6 to release the spring 26 and permit it to expand outwardly to locate within the housing 22 as in Fig. 4. The tool 10 may then be withdrawn from the housing 22 so as to leave the spring 26 loaded within the housing 22 ready for reassembly with the starter mechanism.

The tool 10 and the components thereof may be made of any material such as plastics or metal. The handle configuration 14 of course may be considerably varied and the knob 15 may be replaced by any form of hand grip which will facilitate rotation of the piston assembly 12 and advancement of the plunger assembly. It is not essential that the cap 27 be used in the spring winding process, however, the cap 27 assists in maintaining the spring within the compartment 19.

The bush 23 may either comprise a separate member mounted to the piston assembly 12 or a tubular member formed integrally with the piston assembly 12. In situations where the spring housing 22 does not incorporate a boss 21, the bore 20 may be 6 eliminated and the bush 23 may be any form of stop.

Whilst the above has been given by way of illustrative embodiment of the invention, all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as herein as defined in the appended claims.

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Claims (3)

1. A spring loading tool for loading a spring into a i spring housing, said tool having a main outer body, a chamber within said body, piston means supported within said chamber and normally disposed adjacent one end of said chamber to define a spring receiving compartment therein, said piston means having means with which one end of said spring may engage, actuating means for said piston means and operable to rotate said piston means so as to cause a spring engaged 1 10 therewith to be wound up within said compartment into a spiral form, said actuating means being further operable to move said piston means longitudinally relative to said body so that a said spirally wound spring in said compartment may be displaced from said body and moved in its spiral configuration into said spring housing.

2. A spring loading tool according to Claim 1 wherein said body includes an opening into said compartment through which said spring may pass upon rotation of said piston means.

3. A spring loading tool according to Claim 2 wherein said body is of cylindrical form and wherein said actuating means comprises a handle connected to said piston means. r 25 DATED this thirteenth day of November 1992 ROGER MARTIN HALL BY MY PATENT ATTORNEY JO GARDNER 4 ,4 -ig I