AU596608B2 - Chain - Google Patents

Description

;I i' i- i r i fi h- 596608 SPRUSON FERGUSON FORM 10 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION Class Int. Class Application Number:

(ORIGINAL)

(8.

FOR OFFICE USE: PH2333 9 September 1985 Accepted: Published: rfC'II -08 0?391 Lodged: c Priority: Related Art: Name of Applicant: Address of Applicant: Actual Inventor: Address for Service: 4* 4r 4 44 4 tt

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4 i A it t -PI-PLAR- AUSTRALIA PTY *LIMITED- 17-21 Hunter Street, Parramatta, New South- Wales, 2150, Australia NOEL SYDNEY DAVIDSON WOOD Spruson Ferguson, Patent Attorneys, Level 33 St Martins Tower, 31 Market yNT Street, Sydney, New South Wales, 2000, Australia Complete Specification for the invention entitled:

CHAIN

The following statement is a full description of this invention, including the best method of performing it known to me/us PSP/272F i The present invention relates to chains and in particular to chains which are suitable for, although not exclusively limited to, use in window winder assemblies.

Chains for window winders are known. For example, Australian patent 476701 discloses a chain comprising alternating first and second links, with lateral extensions of the side plates of the links, the lateral extensions cooperating so as to prevent the chain from collapsing in one direction from a straight line condition.

This chain has no resistance to collapsing in the opposite direction however. As a result, when the cha "equires to be bent upon itself in a U-shape for example a supporting sprocket is required to prevent the collapse.

Disclosed as part of the chain winder assembly in AU516364 is a floating sprocket which is arranged such that the inside bend of the U-loop of the chain within the window winder casing engages the said floating sprocket in order to ensure that the loop cannot become kinked or of other than semi-circular form at the inside bend.

"Australian patent 521606 discloses a chain suitable for o D use in a window winder assembly wherein the chain links are identical and are arranged in a nested format. Again, this chain requires a floating sprocket for support.

As will be appreciated, some of the earlier prior art chains require alternate links to be of different construction thus duplicating the design and manufacture process of links for such chains. Some other chains do comprise identical links throughout but in order to achieve this advantage have hitherto required a relatively complex shape.

Whilst all of the referenced prior art chains have the JH/943z -2 chin reur alent link to beL~--I ofI- difeen construction common characteristic of resistance to bending beyond a straight line in one angular direction, none of the cited chains is constructed to prevent the total angular collapse of the chain in the opposite direction. The consequence of this is that, when used in a window w.nder assembly for example, an idler sprocket or similar is required to support the chain at any locations where it is required that the chain bend over upon itself in a U-section profile. Such "floating" or support sprockets are an additional item required purely because of undesirable characteristics of the prior art chains.

It iz an object of the present invention to provide an o, improved chain which will substantially overcome, or ameliorate, the above mentioned disadvantages.

According to the present invention there is provided, a chain comprising a plurality of pivoted links which pivot relative to each other about parallel axes, said links having first and second cooperating surfaces which abut to limit relative rotation between adjacent links to it a first predetermined angle when rotated about said axes in a 0 first direction and to a second predetermined angle when rotated in the opposite direction to said first direction u and wherein links of said chain follow a generally straight or slightly curved path when the surfaces thereof are moved in said opposite direction to an abutting relationship, while following a path of substantial curvature when moved in said first direction to an abutting relationship.

According to a preferred embodiment of the present invention there is provided a chain formed from a plurality of interconnected links, JH/943z 3

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each said chain link comprising two elongated side plates arranged in opposed spaced relationship and being substantially parallel at least at each of two opposite end portions of said link, and a web interconnecting one longitudinal edge of each said side plate to the corresponding longitudinal. edge of the other side plate, and wherein a flange member projects longitudinally from at least one said side plate at both of said opposite end portions o. and wherein a pivot hole is located in said side plate at 0 I) each opposite end at a predetermined position with respect to

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the t~.ansverse ends of said web and wherein said flange projects sufficiently beyond said pivot point such that it engages with the underside of a web of an adjacent link when said links are pivotally connected together such uhat the included angle between said pivotally connected links is limited in a first direction to a S 2b"' predetermined angle.

i In a further preferred embodiment of and in combination with the above, transverse ends of the webs of adjacent pivotally connected links abut when said links are in a predetermined pivotal angular relation, in order to provent said adjacent links from altering their included angular relation in a second direction, said first and second directions being opposite to each other, One embodiment of the present invention will be now be described with reference to the drawings in which:- JH/943z 4 r 4 Fig. 1 is a side section view of the behaviour of a prior art chain, Fig. 2 is a side elevation of the behaviour of the preferred embodiment, Fig. 3 is a perspective, partially exploded, view of the preferred embodiment, Fig. 4 is a side section of the preferred embodiment, Fig. 5 shows top, side, underside, and end views of the preferred embodiment.

Fig. 1 portrays the behaviour of typical prior art window winder chains when folded upon themselves. Such chains collapse, that is to say, there is no means to prevent adjacent chain links from pivoting against one another such that the inlcuded angle between the two links about their mutual pivot Vt V point becomes very small. In order to prevent such collapse when the chain is required to turn upon itself a floating support sprocket is typically inserted at the pivot point of the chain. The following preferred embodiment chain has features which limit the extent to which the chain collapses and n^ 9 2" therefore does not require such a floating support sprocket.

Fig. 2 depicts a chain 1 of the preferred embodiment of I the present invention turning upon itself within a winder body S" 2. Such a configuration is typically found as part of a window winder assembly. See for example Australian patent 516364. In use, one end of the chain 1 is fixed at point 3 within the winder body 2 and the other end is affixed to a window (not shown). A winder mechanism (not shown) feeds the chain 1 into and out of the winder body 2. As depicted in figure 2 the feeding process involves the chain rolling back on itself in a U-shaped configuration. According to a preferred embodiment of JH/943z 5 0- the present invention the chain 1 possesses self supporting features which do away with the requirement for a floating sprocket.

Fig. 3 depicts chain links 4 through to 8 of a preferred embodiment. The links are connected together in staggered fashion by means of rivets or other suitable fastening means through pivot holes, for example 9, 10, and 11, 12.

The rivets for example, 13, 14, 15 connect respective adjacent links such that the links are mutually, pivotally restrained.

Referring in particular to link 4, the link comprises two opposed and generally parallel side members 16, 17 connected 'together by means of a web 18. The web has transverse ends 18A, 18B.

1 Within sides 16, 17 are holes 11, 11A and 12, 12A respectively. These holes are located such that their centres lie on a vertical line extending down from the transverse web 18A, 18B. The said holes also extend partially into the flanges Sof the side members. Flange members 16A, 16B are of relatively 2) short length and extend longitudinally for a sufficient distance 0 o to provide mechanical support for the rivets 13, 14 when inserted and used to connect adjacent links.

Flanges 17A, 17B extending longitudinally from the side member 17 extend further longitudinally than the flanges 16A, 16B. These flanges 17A, 17B provide firstly, mechanical support for the rivets when inserted in the holes 12 and 12A. Secondly, the upper surfaces of said flanges 17A, 178 interact with the underside of the web portions of adjacent links when said links are pivotally connected together.

This interaction is shown in a partial section view in JH/943z 6

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~LI- Fig. 4. Links 19 and 20 are pivotally connected by pin 21. The interconnected links are pivotted about the pin 21 such as to form an included angle 22 measured between the longitudinal axis 23, 24 of links 19, 20 respectively. These longitudinal axes are formed by a straight line connection between the centres of the pivot holes on each link as indicated in Fig. 4.

Link 19 is represented with its side having the longitudinally shorter side member flanges facing out of the page. Adjacent link 20 is represented having the side with the longitudinally longer flanges facing out of the page. The links 19 and 20 are interconnected such that the longitudinally longer flange 25 is pivotted about pin 21 and at the same time nested within link 19. The underside surface 27 of the web of link 19 is shown to be in contact with a portion of the leading edge of flange 25 at a point of intersection designated 28 in Fig. 4.

It is the contact surface defined by intersectica 28 which, acting about the fulcrum provided by pin 21 prevents the included angle 22 between links 19 and 20 from becoming any smaller than shown in Fig. 4.

1 239* Typically, a chpin suitable for use in a window winder <e:e assembly may have a half inch pitch and an included angle 22 limited to approximately 1200° The exact size of this angle is r determined by a number of constraints including the clearance height 29 within the winder-body 2 (Fig. ease of rolling of the chain about its U-bend and desirably obtaining a self supporting characteristic wherein the entry and exit lengths of chain about the U-bend are parallel.

Fig. 5 depicts various views of the chain, link structure and interconnection.

The chain structure, in the preferred embodiment, JH/943z 7 comprises a series of pivotally interconnected links, each link identical, but with each alternate link transposed through 1800 about a vertical axis with respect to its adjacent links. The result is a link structure wherein each link is "staggered" with respect to itr adjacent links. Further, in the preferred embodiment ,vherein the flanges of one side member of each link are longitudinally longer than the respective flanges of the opposed side members of the same link, the chain is assembled such that these longer flanges lie between the sides of and beneath the web of the adjacent link to which the said link is pivotally connected. The relative location of these longer flanges is shown at locations 30 in the underside view of the link structure shown in Fig. 5. Viewed from the side in Fig. on both sides of the chain, only the link sides with the shorter side member flanges are completely visible as generally indicated by 31.

In an alternative embodiment, the chain links may be made completely symmetrical. That is, both of the opposed side j members of each link having side member flanges of equal a t longitudinal length, the said flanges being of sufficient length in order to carry out the included angle limiting function as depicted in Fig. 4. Such an alternative preferred embodiment L' would be equally as effective although aesthetically possibly less pleasing.

As shown in the top view of Fig. 5, in straight condition, the webs 32 to 35 abut the transverse ends of the webs of adjacent links. The abutment of the transverse ends acting about pivots 32A, 33A, 34A serves to limit the included angle between the adjacent links to approximately, or slightly less than 180°. The included angle referred to here is the JH/943z -8 -L r i-

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mirror image of the included angle 22 to which reference was made in Fig. 4.

The features of abutting transverse web ends and elongated side member flanges co-acting with the inside surfaces of the webs of adjacent links serve to provide a chain structure which resists the pivoting of adjacent links beyond approximately a straight line relative to each other in one direction and resists the pivoting of the links in the other direction such that an included angle of approximately 1200 is always maintained in said opposite direction.

A chain with such characteristics is particularly suited O*o I for use in window winder assemblies as previously described o herein.

Go b The foregoing describes only two embodiments of the present invention and modifications obvious to those skilled in the art can be made thereto without departing from the scope of the present invention.

In particular, the first and second included angles depend on the relative position of the pivot point with respect to the web transverse ends and the length of flanges of the side members. The relative positions of these may be varied to achieve the same results as disclosed herein without departing I from the scope of this invention.

Further, cooperating surfaces other than those defined above, may be used to achieve the same effects, JH/943z 9

Claims (4)

1. A chain comprising a pluarality of adjacent, identical interconnected links, each link comprising parallel first and second.flat side members connected by means of a web; the web having a top and bottom surfaces; the first side members each further comprising first longitudinally extending flanges; the second side members each further comprising second longitudinally extending flanges; the flanges providing mechanical support for rivets used to connect adjacent links; adjacent links interconnected such that the first flanges are nested within each adjacent link, the first flanges extending so as to limit an included angle between adjacent links by contacting the bottom surface of the web of an adjacent link when said included angle is reached,

2. The chain of claim 1 wherein the second flanges are the same as the first flanges. Ot

3. The chain of either of claims 1 or 2 where the included angle is S about 120 degrees.

4. A chain as hereinbefore described with reference to Figs. 2 to t DATED this SEVENTEENTH day of JANUARY 1990 Naco Aus'tralia Pty Limited ono Patent Attorneys for the Applicant SPRUSON FERGUSON 0 o 4 hI