AU610733B2 - Rotary clothes hoist operating mechanism - Google Patents

Description

i i~ FORM COMMONWEALTH OF AUSTRALIA6 Patents Act 1952 0 COMPLETE SPECIFICATION (Original) Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: S..Priority: ,Related Art: C, l .r~n rrnc1 f~lV

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*t 9 9 4 99 ,Name of Applicant: DENNIS JOHN SKERRY Address of Applicant: 78 White Street, Mordialloc, Victoria, Australia.

Actual Inventor: DENNIS JOHN SKERRY Address for Service: EDWD. WATERS SONS, QUEEN STREET, MELBOURNE, AUSTRALIA, 3000 Complete Specification for the invention entitled: ROTARY CLOTHES HOIST OPERATING MECHANISM The following statement is a full description of this invention, including the best method of performing it known to me.

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0 0 0o 0o 0 0 0 a 00 0 0 o r os o D QOOo -2- ROTARY CLOTHES HOIST OPERATING MECHANISM The present invention relates to operating mechanisms for rotary clothes hoists.

Rotary clothes hoists conventionally have been constructed consisting of a lower tubular upright member that is adapted to be supported in a stationary manner at a suitable ground location. This member might be fixed in position or might be selectably movable from a ground support base so that the entire hoist assembly, in the case 10 of a foldable construction, can be removed for storage until i0 it is desired to use the hoist assembly again. Such rotary hoist assemblies further include a tubular upper member capable of sliding movement within the lower member both in vertical as well as rotary directions. The upper end of 15 this tubular upper member carries suitable support arms 1 5 which in use extend radially and carry flexible lines for carrying clothes for outside drying. The support arms may be foldable or fixed depending on whether the entire unit is intended to be removable for storage purposes.

20 Conventionally rotary hoists of this general type have included an operating mechanism having an external rotatable handle mounted on the lower stationary tubular member at a convenient height for manual gripping which effects raising or lowering of the upper tubular element upon rotation of the rotary handle in a desired direction. Numerous forms of operating mechanisms have been used to achieve this basic operation. In one typical arrangement such as shown in Australian Patent Nos. 252391 and 213610, the lower stationary tubular member is cut transversely with the upper 30 and lower sections formed by a longitudinally split outer casing. The casing houses a ring gear rotatable about a vertical axis and operates by a pinion gear turned by the external rotatable handle, the pinion gear rotating about an axis generally normal to and intersecting the longitudinal axis of the upright tubular members. A longitudinal screw element engages an internal threaded bore in the inner ring gear and moves up and down depending on the direction of a 0 0 0 O0 0 00 p 0* r, 7 i

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o *O 9 a os a a+ -3rotation of the ring gear. The upper end of the screw element carries a fitting adapted to engage with a lower end of the upper movable tubular element in a manner permitting the screw element to move the upper tubular element in a verticial direction without restricting rotary movement.

Such constructions result in a bulky and therefore heavy casing construction around the operating mechanism which makes them generally unsightly. Moreover the fitting engagement of the screw element with upper movable tubular 10 upright member have generally either been too weak and i0 therefore prone to failure in use, or too strong, once engaged, to effectively prevent disengagement for servicing purposes.

Australian Patent Specification Nos. 506744 and 15 46673/85 disclose operating mechanism arrangements which 15 avoid the need to cut the lower tubular upright and therefore, to some extent avoid the need for the heavy external casing members around the operating mechanism.

These mechanisms include small ring gears having an outer 20 peripheral dimension less than the internal diameter of the 2O tubular uprights. The ring gears are rotated by a pinion gear rotating about an axis normal to the longitudinal axis of the upright tubular members. As a result, an access hole largely equivalent to the external dimensions of the pinion 25 gear needs to be formed in the outer wall of the lower stationary upright tubular member which substantially weakens its strength. Australian Patent Specification No.

46673/85 accommodates for this weakening by providing an outer casing around the operating mechanism despite the fact that the lower tubular upright member is not cut completely.

Both these specifications also have the same difficulties with the fittings operating between the screw element and the lower end of the upper movable tubular member as discussed previously with reference to the earlier prior patent specifications.

The objective of the present invention is to provide an effective rotary hoist operating mechanism which 4 avoids the need for heavy separate casing members around the operating mechanism and which does not require large weakening cut out regions from the tubular upright support members. A further preferred embodiment of the present S invention is to provide an effective connection between the j operating mechanism and the movable tubular support member i that will be robust in operation but is relatively simple to disassemble for maintenance if required.

A r e- present -i-n-ne.~s-en-p-r-ov-ides-- S operating mechanism fo a rotary hoist of the type including I a lower stationary tubu ar support element and an upper co-axial tubular support\element, the upper support element being moved along a longi udinal upright axis in an upward or downward direction relat've to the lower support element 15 by said operating mechanism, said operating mechanism S15 comprising a pinion drive gea rotatable about a first axis *0 transverse to said longitudina upright axis with said first axis being located wholly outsi e of said tubular support elements, a pinion driven gear otatable about a second axis 2 coincident with or parallel to s id longitudinal upright 2 axis with said pinion driven gear being located wholly or substantially within the lower sta ionary support element of the rotary hoist, said pinion drive gear and said pinion drive gears having intermeshing heli 1 or part helical teeth, said driven gear being support by bearing means for rotation about said second axis and being restrained from axial movement along said longitudinal upright axis, said 0 driven gear further having an inner axial bore internally 0 threaded through which an elongated extern lly screw threaded rod member is passed with said in ernally threaded Sbore of said driven gear in engagement with he externally screw threaded rod member whereby rotation ofsaid driven pinion gear effects upward or downward movemen of said rod member without rotation of said rod member, and\connection means arranged at an upper end of said rod membe to secure -a--owe-r end of the lower- tubu-a--sup.pt-e-e-ment- here-to-.

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k A* //i _1 I -I 4a Accordingly the present invention provides an operating mechanism for a rotary hoist of the type including a lower stationary tubular support element and an upper co-axial tubular support element, the upper support element being moved along a longitudinal upright axis in an upward or downward direction relative to the lower support element by said operating mechanism, said operating mechanism comprising a pinion drive gear rotatable about a first axis transverse to said longitudinal upright axis with said first axis being located wholly outside of said tubular support elements, a pinion driven gear rotatable about a second axis coincident with or parallel to said longitudinal upright axis with said pinion driven gear being located wholly or substantially within the lower stationary support element of the rotary hoist, said pinion driven gear and said pinion drive gears having intermeshing helical or part helical o teeth, said driven gear being supported by bearing means for rotation about said second axis and being restrained from axial movement along said longitudinal upright axis, said +m I.

driven gear further having an inner axial bore internally threaded through which an elongated externally screw threaded rod member is passed with said internally threaded bore of said driven gear in engagement with the externally screw threaded rod member whereby rotation of said driven 25 pinion gear effects upward or downward movement of said rod member without rotation of said rod member, and connection P means arranged at an upper end of said rod member to secure a lower end of the lower tubular support element thereto.

I ,e ~nars~ The arrangement thus described enables a relatively thin drive pinion gear to be employed such that its drive teeth intermeshing with teeth of the driven gear can pass through a quite narrow and small slot like opening in the wall of the lower tubular support element. Thus this wall is weakened only to a minimum extent and the operating handle can be secured to the lower tubular support element by a quite small casing that does not need to surround the tubular support element. As a result, a lighter, stronger 10 and better looking operating mechanism is achieved with i0 respect to the above described prior art.

One preferred embodiment of the present invention *ro will hereinafter be described with reference to the e* *accompanying drawings, in which: 1 Figure 1 is a longitudinal transverse sectional 15 view of operating apparatus in accordance with one preferred "embodiment of the present invention; *Q *Figure 2 is a transverse sectional view taken along line A-A of figure 1; 20 Figure 3 is a transverse sectional view taken along 20 Sline B-B of figure 1; and i Figure 4 is a transverse sectional view taken along line C-C of figure 1.

o Referring now to figure 1, there is shown an 25 operating mechanism 10 for a rotary hoist in an installed position. The rotary hoist includes a lower tubular o" stationary upright support member 11 and a movable upper o tubular support member 12 coaxial with the member 11 and slidably received therein. The operating mechanism 10 is 30 generally housed within the upright stationary membe: 11 3O except for a drive pinion gear 13 mounted on a shaft 14 extending transverse to the tubular support members 11,12.

The shaft 14 is mounted externally of the support member 11 in a small external casing 16 and the drive gear 13 extends only a short distance into the support member 11. An operating handle 15 is providea to turn the shaft 14 and thereby the drive pinion gear 13. The shaft 14, gear 13 and 7 -6operating handle 15 are supported in or by the small external casing 16 secured to the lower tubular support member 11 by appropriate fasteners 17,18.

Arranged within the lower tubular support member 11 is a driven pinion gear 19 having an axis of rotation, in the embodiment illustrated, generally coincident with the longitudinal upright axis of the tubular support members 11,12. The gear 19 has helical or part helical radial teeth meshing with similar teeth on the drive gear 13.

Conveniently both the gears 13,19 might be moulded from suitable industrial grade plastics material to provide inexpensive production and quiet and reliable operation.

Intermeshing of the two gears 13,19 is achieved through a o, relatively thin and small opening 52 in the wall of the 15 support 11 which minimizes any weakening effect caused thereby. The gear 19 includes an upper boss 20 and lower c "boss 21 (of greater axial length than boss 20) the lower a °o boss 21 being received within a plain bearing extension 22 of a lower keeper element 23. The keeper element is 20 maintained stationary and in the position illustrated by screws 17. An upper keeper element 24 is provided held oo stationary in the position illustrated by screws 18. Thus the driven gear is restrained axially by the lower face 26 oof the keeper element 24 and the upper edge 27 of the 25 bearing extension 22 of the lower keeper element 23. The driven gear 19 is restrained for rotary motion by the o o ~bearing extension 22.

o An elongated rod member 28 is provided that extends axially through the tubular support members 11,12, the rod 30 member 28 having externally screw threaded sections 29 engaging with internally screw threaded sections 30 in a bore extending axially through the driven gear 19. The rod member 28 also incudes at .east one and preferably two axially extending flats 31 that co-operate with the upper keeper element 24 to prevent rotation of the rod member 28 about its axis. As is apparent from figure 3, the upper keeper element 24 includes an inner boss 32 with reinforcing i: -7webs 33. The inner boss 32 includes a central bore 34 corresponding to the general cross-sectional shape of the rod member 28. Thus the flat faces 35 of the bore 34 engage with the flat surfaces 31 of the rod member 28 to ensure that the rod member 28 cannot rotate but can only move in an axial direction through the bore 34. In consequence when the driven gear 19 is rotated the internal threads 30 act with the threaded sections 29 of the rod member 28 to move the rod member 28 either axially upwardly or axially downwardly.

Arranged at the upper end of the rod member 28 is an engagement fitting 36 adapted to inter connect with an engagement fitting 37 on a lower end of the tubular support member 12. The fitting 36 includes upper and lower webs 38,39 interconnected primarily by a pair of parallel r. 15 transverse webs 40,41 defining a guide slot 42. The upper *o o, web 38 includes a radially extending slot 43. The fitting 37 includes an inner annular extension 44 adapted to be secured by any suitable means inwardly of the lower end of the tubular support member 12. The fitting 37 includes a Stransverse web 45 below the annular extension 44 and a CO central rod 46 extending downwardly therefrom. The diameter o of the rod 46 is slightly less than the width of the slot o° o 43. At the lower end of the rod 46 is an enlarged head 47 of a diameter approximating the width of the guide slot 42 and significantly greater than the width of the slot 43.

~Thus in assembly, the rod 46 can be slid into the slot 43 S6 and the head 47 is then firmly captured between the webs o 38,39 and 40,41 and by the wall of the tubular support 11.

30 Thus the elements are easy to assemble or disassemble but 3O are robust in operation.

The lower keeper element 23 includes a cerntral transverse web 48 from which the bearing extension 22 extends upwardly and a downwardly extending annular extension 49 secured by the screws 17. Lower radial webs 3 5 at and upper radial webs 51 serve to strengthen the element.

Claims (5)

1. An operating mechanism for a rotary hoist of the type including a lower stationary tubular support element and an upper co-axial tubular support element, the upper support element being moved along a longitudinal upright axis in an upward or downward direction relative to the lower support element by said operating mechanism, said operating mechanism comprising a relatively thin pinion drive gear rotatable about a first axis transverse to said longitudinal upright axis with said first axis being located wholly outside of said tubular support elements, a pinion driven gear rotatable about a second axis coincident with or parallel to said longitudinal upright axis with said pinion driven gear being located wholly or substantially within the lower stationary tubular support element of the rotary hoist, said pinion driven gear and said pinion drive gear having intermeshing helical or part helical teeth engaging through a small opening in a wall of said lower stationary tubular support element, said pinion driven gear being supported by bearing means for rotation about said second axis and being restrained from axial movement along said longitudinal upright axis, said pinion driven gear further having an inner axial bore internally threaded through which an elongated externally screw threaded rod member is passed with said internally threaded bore of said dri¢-n gear in engagement with the externally screw threaded rod member whereby rotation of said driven pinion gear effects upward or downward movement of said rod member without rotation of said rod member, and connection means arranged at an upper end of said rod member to secure a lower end of the lower stationary tubular support element thereto.

2. An operating mechanism according to claim 1 wherein said driven gear includes a downwardly depending bearing section captured within a bearing portion of a stationary keeper element secured to the lower stationary tubular 9 support element and an upper stationary keeper element is provided to prevent axial movement of said driven gear.

3. An operating mechanism according to claim 2 wherein said rnd member includes at least one axially extending section cooperable with one of said keeper elements to prevent rotation of said rod member.

4. An operating mechanism according to claim 3 wherein said axially extending section(s) comprises at least one axially extending flat surface.

5. An operating mechanism according to any one of the preceding claims wherein either an upper end of the rod 0 member or a lower end of the upper coaxial tubular support element carry connection means engagable with an axial io>° extending rod with an enlarged head portion carried by the oo other of said rod member or lower end of the upper coaxial tubular support element, said connection means including a transverse plate with a dimension approximately but smaller than the inner dimensions of the lower stationary tubular support element, said transverse plate carrying a radial slot of a width greater than the diameter of the axially extending rod but less than the diameter of said enlarged head portion. e DATED this 25th day of January, 1991. DENNIS JOHN SKERRY WATERMARK PATENT TRADEMARK ATTORNEYS, 290 Burwood Road, HAWTHORN. VIC. 3122 AUSTRALIA 1 p1