AU619988B2 - Improvements to clothes hoist elevating means and the method of assembly therefor - Google Patents

Description

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Form COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952-62 COMPLETE SPECIFICATION

(ORIGINAL)

649988 FOR OFFICE USE: Application Number: Lodged: Class Int. Class Complete Specification Lodged: Accepted: Published: Prfority: Related 'Art: 0 0 0 0

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Nam& of Applicant: TO BE COMPLETED BY APPLICANT HILLS INDUSTRIES LIMITED a Address of Applicant: Actual Inventor: dreor Service: Ad'dress'for Service: 944-956 South Road, Edwardstown, State of South Australia, Australia JOHN KLYNTON KITTO and RONALD GRIERSON MEADE Care of R K MADDERN ASSOCIATES, 345 King William Street, Adelaide, South Australia, 5000 Complete Specification for the invention entitled: "IMPROVEMENTS TO CLOTHES HOIST ELEVATING MEANS AND THE METHOD OF ASSEMBLY THEREFOR" The following statement is a full description of this invention, including the best method of performing it known to me. us.

-1- PATENT, TRADE MARKS DESIGNS SUB-OFFICE 18 JUN 1990 SOUTH AUSTRALIA 7 Lll_ t.

This invention relates to improved elevating means for elevating the upper standard of a clothes hoist of the type used for the drying of clothes and which comprises a fixed lower standard, an elevating upper standard which may rotate, and an operating handle projecting from one side of the fixed lower standard.

Various forms of hoist elevating means for clothes hoists of the aforementioned type are well known and normally employ a rotating handle journalled in a bearing block carried on the outer surface of the fixed lower standard, the handle having a spindle on the inner end of which is carried a driving pinion 0 within the lower standard, the driving pinion meshing with a driven pinion carried on one end of a nut which is itself held captive against axial movement and which threadably engages a 00o non-circular threaded worm which, upon rotation of the nut, raises or lowers the upper standard. Two such arrangements are described and illustrated in the applicant's earlier Australian Patent Nos. 506744 and 578725.

Clothes hoists constructed in accordance with the aforesaid Australian Patents have been used extensively and generally have proved satisfactory in use. However, a potential structural weakness exists in the fixed lower ~standard in the vicinity of the handle where it has been normal procedure for a relatively large diameter hole to be formed in the wall of the lower standard to enable the driving pinion and co( the shaft or shank on which it is mounted to be inserted therethrough during the assembly of the clothes hoist.

Normally the hole has a diameter of approximately 43mm which is drilled in the wall of the standard and the metal surrounding the hole deformed to provide a circular skirt-like flange which projects outwardly from the standard. The presence of the relatively large aperture or hole in the standard wall structurally weakens the standard and may give rise to fatigue failure during the working life of the hoist. It will of course be appreciated that a rotary clothes line, when in use, is subjected to significant loading by virtue of the weight of the clothes hung thereon and that such loading continually changes as the hoist rotates. Often the loading is uneven resulting in the clothes hoist standard being subjected to vibrational stresses. In extreme cases a fracture may occur in the region of the handle, causing the hoist to collapse, which poses a serious safety threat to any person in the vicinity of the hoist.

It is the main object of the present invention to provide improvements to hoist elevating means which overcomes or obviates the above-stated problem, and which provides an a rrangement wherein the standard is far less likely to suffer e0,, fatigue fracture during its working life.

It is a further object of the present invention to provide an improved clothes hoist elevating means which can be readily *0* S and simply assembled and fitted to the standard during the production of the hoist.

It is a still further object of the present invention to provide improvements in and to a clothes hoist of the rotary type which will result in the hoist having a significantly t t longer working life.

According to one aspect of this invention therefore, there is provided a clothes hoist of the type comprising a fixed C cc 9 lower tubular standard and an upper tubular elevating standard, S and elevating means for raising the upper standard with respect to the lower standard, wherein said elevating means comprises a tubular inner member housed coaxially within the lower standard, an opening formed in the side wall of said tubular inner member, and means for securing the tubular inner member against axial and rotational displacement, a driving pinion positionable within said opening and supported by said tubular inner member for rotation about an axis at right angles to the polar axis of the lower standard, a driven pinion meshing with said driving pinion, said driven pinion being supported within said tubular inner member for both rotation and axial thrust, a nut secured to said driven pinion and rotative therewith, a non-circulai threaded stem extending through the tubular Sinner member and axially movable with respect thereto, said stem being restrained against rotational movement, the thread of said stem being engaged by the inner thread surface of the nut, such that rotation of the driving pinion effects rotation of the nut which in turn raises or lowers the stem, I. I a support means on the upper end of the threaded stem ,supporting the upper standard, said lower standard being a continuous tubular member but having an aperture extending through the wall thereof, said o. aperture being small relative to the diameter of the lower standard, a rotatable handle arm adjacent one side of the lower standard, and a driving shaft extending through said aperture, said o0o0 driving shaft at one end being coupled to said handle arm for rotation therewith and at its other end to said driving pinion, wherein the diameter of the driving pinion is large relative to the size of said aperture in the wall of said lower standard.

Preferably the diameter of the aperture in the wall of the fixed lower standard is in the range of 12mm to 16mm, preferably approximately 12mm which contrasts with a diameter of 43mm for holes or apertures drilled in existing standards.

As a result, the structural strength of the standard in the vicinity of the aperture is not significantly impaired and certainly not to the same extent as occurs with a hole having a diameter in the order of 43mm.

In another aspect of this invention, there is provided a method of assembly of hoist elevating means for a clothes hoist -4of the type comprising a fixed lower tubular standard and an upper tubular elevating standard, comprising the steps of:forming a hole or aperture extending through the wall of the fixed lower standard, said aperture being small relative to the diameter of the lower standard, slidably locating a thrust tube sub-assembly along the interior of the fixed lower tubular standard, said sub-assembly comprising a tubular inner member, a driving pinion loosely supported within the confines of the tubular inner member, a nut carrying at its upper end a driven pinion which meshes with said driving pinion, and a non-circular threaded stem or worm r" C C which threadably engages the inner threaded surface of said nut, aligning the tubular inner member of the sub-assembly with I. respect to said aperture so that the hub of the driving pinion is horizontally aligned with said aperture, securing the tt 1 tubular inner member of the sub-assembly with respect to said fixed lower standard,inserting the inner end of a driving shaft through said aperture so as to drivingly engage said driving pinion, the aperture being dimensioned such that the driving shaft passes therethrough with small clearance, and securing S the outer end of the driving shaft to a handle arm so as to S rotate therewith.

Preferably the tubular inner member of the thrust tube sub-assembly is provided at its leading end with a forwardly projecting locating lug which is arranged to engage a retractable locating pin projecting through a hole in the wall .4 of the fixed lower standard to thereby locate the sub-assembly in its correct position within the standard, at which position the driving pinion is aligned with the aperture in the wall of the lower standard, subsequent to which a self-tapping screw is used to fixedly locate the sub-assembly to the standard. The locating pin is then retracted.

In order to more fully describe the present invention, an embodiment is described hereunder with reference to the accompanying drawings in which; Fig. 1 is a vertical cross-section taken through the standard and the elevating mechanism; Fig. 2 is a transverse cross-sectional view of Fig. 1; and I Fig. 3 is an exploded fragmentary view of the elevating mechanism.

In this embodiment, a rotary clothes hoist comprises a fixed tubular lower standard 10 and an upper tubular standard 11 which is an elevating standard and is telescopically movable S. within the upper open end of the lower standard 9 o The lower standard 10 is provided with a small diameter i° naperture 12, in this embodiment approximately 12mm, in its wall intermediate the ends thereof.

00 Positioned within the lower standard 10 is a thrust tube sub-assembly comprising a tubular inner cup-like member 13 which is fastened by a self-tapping screw 14 to the standard 00$0 .0000 10, the tubular member 13 supporting adjacent its lower end an i a a internally threaded nut 15 which has integrally formed therewith at its upper end a crown wheel 16, the nut threadably engaging a flat sided worm 18 which is non-rotatably and axially movable relative to the tubular member 13 (this being in accordance with the construction disclosed in the applicant's aforesaid Australian Patents).

The crown wheel 16 meshes with a pinion gear 20 loosely supported for rotation within the tubular inner member 13, the axis of rotation of the pinion gear 20 being at right angles to the axis of rotation of the crown wheel 16. The arrangement is such that rotation of the driving pinion 20 causes elevation or lowering of the worm 18 which in turn effects raising or lowering of the upper standard 11.

-6- In this embodiment, the pinion gear 20 is supported by means of a saddle 21 which snap-fittingly locates in a partcircular opening 22 formed in the wall of the tubular member 13, the part-circular opening 22 being formed with opposed channel slots 23 in which are located respective wing portions 24 projecting laterally from the saddle 21, the saddle 21 extending transversely of the member 13 and being lcated between the worm 18 and the opening 22 formed in the side wall of the member 13.

The saddle 21 is formed with a central hole 25 in which is I journalled an annular bearing portion 26 on the inner end of the pinion gear 20. The gear 20 locates in a recessed portion 27 of the saddle 21, portion 27 being shaped to conform 19" approximately to the inner peripheral surface of the pinion gear The pinion gear 20 is formed with a central bore 28 of square shape in which is removably inserted the inner end of a square section driving shaft or shank 29, the outer end of the shaft 29 being keyed to a handle assembly 30 so that rotation 'of the handle assembly 30 rotates the shaft 29 to in turn rotate the pinion gear 2U.

In this embodiment the handle assembly 30 comprises a rotatable bush 31 which is journalled for rotation in a bearing skirt 32, and a barbed bifurcate bar 33 extending axially through the bush 31 and in snap fitting engagement therewith.

The driving shaft 29 is frictionally retained between the prongs of the bifurcate bar 33 and has its inner end projecting through the aperture 12 in the wall of the lower standard Since the driving shaft 29 only extends through the wall of the standard 10, the diameter of the aperture 12 need only be slightly greater than the width (diameter) of the shaft 29.

The bearing skirt or block 32 forms part of an inner cover 34 which is fixedly secured to the outer surface of the fixed -7-

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i I I t C 30 3520 I 30 i, lower standard 10, the cover 34 being retained by fastening screws 35 which pass through the wall of the standard 10 and into the wall of the member 13. Outer cover plate members 36 which co-operate with one another across a diametral plane surround the lower standard 10 in order to conceal the inner cover 34.

An O-ring 37 is located between an out-turned annular flange at the inner end of the bush 31 and an internal shoulder formed in the bore of the skirt 32, and which, on rotation of the handle, is compressed and applies pressure on the bush.

The handle assembly 30 also comprises a swinging handle arm 38 which has a handle 39 pivoted thereto to facilitate the winding thereof.

The lower end of the standard 11 is coupled to the threaded stem 18 by means of a support cup 42 retained within, the support cup 42 being supported on a base cross 43 integrally formed adjacent the upper end of the stem 18, there being a barbed spigot 44 upstanding from the base cross 43 and which projects through a hole in the base of the support cup 42 to thereby lock together the cup 42 and the stem 18. This is in accord with the construction described in the applicant's Australian Patent 578725.

All elements apart from the upper and lower standards 11 and the shaft 25 are formed from polymeric material having good bearing characteristics so that there is no need for the mechanism to be provided with lubricants. However, the shaft 29 can be provided with a central passageway extending the length thereof and which can be used to admit a lubricant into the elevating mechanism if required.

In the assembly of the clothes hoist, the standard 10 is held in a jig and the thrust tube assembly slidably located along its interior (being inserted from the top end thereof)

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until the central bore 28 of the pinion gear 20 aligns with the aperture 12 in the wall of the standard 10, whereupon the tubular member 13 is fixedly secured to the standard 10 (by means of the screws 35), followed by the fitting of the handle and cover assembly 30, with the inner end of the driving shaft 29 being inserted through the aperture 12 and engaged in the non-circular central bore 28 of the pinion gear 20, and its $i outer end secured to the handle arm 38.

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I C C I 13 C A retractable pin (not shown) is inserted through a hole in the wall of the standard 10 and co-operates with a locating lug 41 projecting forwardly from the leading end of the tubular inner member 13 in order to accurately position the pinion gear 20 relative to the aperture 12. The pin is subsequently withdrawn ready to repeat the cycle for the next clothes hoist.

A consideration of the above-described embodiment will indicate that the invention is extremely simple but nevertheless provides a very simple arrangement for a clothes hoist elevating mechanism which can be fitted to the standard without having to form a relatively large hole in the wall of the standard, as a result of which the buckling strength of the standard is not significantly impaired and the likelihood of the standard suffering fatigue failure during its life is minimised.

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Claims (2)

1. In a clothes hoist used for drying clothes comprising a fixed lower tubular standard and a movable upper tubular Selevating standard, improved elevating means for raising the upper standard with respect to the lower standard, wherein said elevating means comprises a tubular inner member housed coaxially within the lower standard, an opening formed in the side wall of said tubular inner member, and means for securing the tubular inner member against axial and rotational displacement, I tr ,a driving pinion positionable within said opening and S .supported by said tubular inner member for rotation about an axis at rizqht angles to the polar axis of the lower standard, a driven pinion meshing with said driving pinion, said driven pinion being supported within said tubular inner member for both rotation and axial thrust, a nut secured to said driven pinion and rotative therewith, a non-circular threaded stem extending through the tubular inner member and axially movable with respect thereto, said stem being restrained against rotational movement, the thread of said stem being engaged by the inner thread surface of the /nut, such that rotation of the driving pinion effects rotation of the nut which in turn raises or lowers the stem, support means on the upper end of the threaded stem supporting the upper standard, said lower standard being a continuous tubular member but having an aperture extending through the wall thereof, 'sa-d i 30 aperture being small relative to the diameter of the lower standard, a rotatable handle arm adjacent one side of the lower standard, and *i a driving shaft' extending through said aperture, said driving shaft at one end being coupled to said handle arm fon rotat.on therewith and at its other end to said driving pinion, XC^>\Z~i -io"- i I C I II Vc II,. C 44 4 4

44.4 *r .1 wherein the diameter of the driving pinion is greater than the size of said aperture in the wall of said lower standard. 2. Improved elevating means according to claim 1 wherein said tubular inner member is arranged to lie approximately contiguous with the inner surface of the lower standard, and wherein said driving pinion is loosely supported within the confines of the tubular inner member. 3. Improved elevating means according to either claim 1 or claim 2 wherein said tubular inner member comprises a transversely extending removable saddle plate insertable within and bridging said opening in the side wall of the tubular inner member and being located between the threaded stem and said opening, said saddle plate being formed with a central hole in which is journalled an annular bearing portion on the inner end of said driving pinion, 4. Improved elevating means according to any preceding claim wherein said driving pinion is formed with a non- circular central bore in which is removably inserted the inner end of said driving shaft. 5. Improved elevating means according to any one of the preceding claims further comprising a cover member secured to said wall of the lower standard over said aperture, said handle arm being rotatably supported by said cover member. vi- 6. Improved elevating means according to any preceding claim wherein said cover member comprises a bearing surface, a bush journalled for rotation in said bearing surface, said handle arm comprising a barbed bifurcate spindle projecting inwardly from the central portion thereof coaxially through said bush, keying means between said bush and said spindle, said driving shaft having its outer end frictionally retained between the barbs of said bifurcate spindle. -11- 1 7. c= lothe.... 1..t according to any preceding claim wherein the aperture formed in the wall of said lower standard is circular and has a diameter in the range of 12mm to 16mm. 8. An improved method of assembly for a clothes hoist of the type comprising a fixed lower tubular standard and an upper tubular elevating standard, comprising the steps of; forming an aperture extending through the wall of the fixed lower standard, said aperture being small relative to the diameter of said lower standard, (ii) slidably locating a thrust tube sub-assembly along the interior of the fixed lower tubular i standard, said sub-assembly comprising a tubular t* inner member, a driving pinion loosely supported S, within the confines of the tubular inner member, a nut carrying at its upper end a driven pinion which meshes with said driving pinion, and a non-circular threaded stem or worm which threadably engages the inner threaded surface of said nut, S(iii) aligning the tubular inner member of the sub- assembly with respect to said aperture so that the hub of the driving pinion is horizontally aligned with said aperture, (iv) securing the tubular inner member of the sub- assembly with respect to said fixed lower standard, inserting the inner end of a driving shaft through said aperture so as to drivingly engage said driving pinion, the aperture being dimensioned such that the driving shaft passes therethrough with small clearance, and -r -12- rA lv 0 (vi) securing the outer end of the driving shaft to a handle arm so as to rotate therewith. 9. An improved method according to claim 8 also comprising the steps of: fitting a cover against the wall of the lower standard so as to overlie said aperture, and securing the cover to said fixed lower standard, said handle arm being rotatably carried by said cover. An improved method according to claim 8 or claim 9 wherein the step of aligning the tubular inner member with respect to said aperture comprises: S' actuating a retractable locating pin so as to project bi *through a hole in the wall of the fixed lower standard, said ,I C' WO Z S- hole being locatedAl said lower standard. tV iso sa\c e sliding the thrust-tube sub-assembly along the lower standard until the leading end of the tubular inner member, abuts against said locating pin whereat the driving pinion is horizontally aligned with said aperture. 11. An improved method according to claim 10 followed by Sr' the step of retracting the locating pin from its hole after the completion of step (iv). 12. An improved method according to any one of claims 8 Sto 10 wherein said aperture is a circular hole having a diameter in the range of 12mm to 16mm. 13. A clothes hoist elevating mechanism substantially as described herein and as illustrated in the accompanying drawings. Dated this 18th June 1990 HILLS INDUSTRIES LIMITED SBy its Patent Attorneys R.K. MADDERN ASSOCIATES -13- G t(