AU653554B2

AU653554B2 - Prickle chain and link therefor

Info

Publication number: AU653554B2
Application number: AU86027/91A
Authority: AU
Inventors: Neil Bernard Norrish
Original assignee: N B NORRISH
Current assignee: Norrish Nb
Priority date: 1990-11-30
Filing date: 1991-10-22
Publication date: 1994-10-06
Anticipated expiration: 2011-10-22
Also published as: AU8602791A

Description

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AUSTRALIA

PATENTS ACT 1990 P/00/011 Regulation 3.2 -53554 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Address of Applicant:

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'e g Actual Inventor: Address for Service: NEIL BERNARD NORRISH P.O. BOX 54 TRAYNING W.A. 6488 NEIL BERNARD NORRISH GRIFFITH HACK CO., PATENT TRADE MARK ATTORNEYS, 256 ADELAIDE TERRACE, 6TH FLOOR, PERTH W.A. 6000 Standard Complete Specification for the invention entitled: SeeS 5555 eSS.

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0S PRICKLE CHAIN AND LINK THEREFOR Details of Associated Prov'sional Applications: Australian Provisional Patent Application No. PK 3639 dated November 1990.

The following is a full description of this invention, Including the best method of performing It known to me:- 2 PRICKLE CHAIN AND LINK THEREFOR The present invention relates to a prickle chain and link therefor.

Prickle chains (also known as harrow prickles) are commonly used to break clods or remove weeds from large areas of land. Typically, prickle chains comprise conventional metal chains where a plurality of tines are welded to each link of the chain. The construction of conventional prickle chains is time consuming due to the need to weld individual tines to each link. This is reflected in the relatively high cost of conventional prickle chains. In addition, each link of the prickle chain is permanently attached to an adjacent link. Thus, the length of the chain may only be varied by either cutting the chain to reduce the length or welding end 15 links of separate chains to increase the length.

The present invention was developed with a view to providing a prickle chain and link therefore which are simple in construction and relatively inexpensive to produce, and in which the length of the chain may be conveniently varied.

20 According to one aspect of the present invention there is provided a substantially planar link for a prickle chain, said link comprising: gao central linking portion and first and second arms connected to and extending away from said central linking portion in different directions; said arms being spaced apart in a direction transverse to their length, wherein the central linking portion of each link is shaped such that when a pair of said links are arranged so that the central linking portions of each link overlap in a manner where the respective first arms extend in different directions, the central linking portions form first and second continuous loops, whereby, in use, a first loop formed by overlapping one pair of links can releasably engage a second loop formed by an adjacent pair of overlapping links.

3 Preferably, said central linking portion is substantially S-shaped.

Preferably, said first and second arms are integral with said central linking portion which is formed intermediate of said first and second arms.

According to another aspect of the invention there is provided a prickle chain comprising: a plurality of links according to the first aspect of the invention, said links arranged in pairs, the links in each pair arranged such that the respective first arms of each link extend in opposite directions and the central linking portion of each link overlap to form first and second continuous loops, said pairs arranged so that a first loop of one pair of said links releasably engages a oeo• 15 second loop of an adja(.-nt pair of links, thereby forming ;said prickle chain.

"Preferably, said adjacent pair engage with said one pair by passing the second arm of one of the links of said adjacent pair through the first loop formed in said S" 20 one pair, in one direction, and passing the second arm of to.. the other link of said adjacent pair through the first loop in an opposite direction.

Preferably, said opposite adjacent pair can be made to engage with said one pair by passing the first arm d.*O of one of said links of the opposite adjacent pair through the second loop formed in said one pair in one direction, and passing the first arm of the other link of the opposite _7 4adjacent pair through the second loop in an opposite direction.

Preferably, said central linking portion is substantially S-shaped.

Preferably, said continuous loop formed by the overlapping central link portions in a pair of links is of substantially figure-eight-shaped construction.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a front view of the link for the prickle chain; Figure 2 is a front view of a pair of overlapping links; and, Figure 3 is a perspective view of two pairs of overlapping links releasably engaging each other to form part S.o of the length of the prickle chain.

Referring to the drawings, it can be seen that the Go* link 2 for a prickle chain comprises a central linking 20 portion 4 in the form of an "S-bend" and first and second arms 6 and 8 respectively which are connected to and extend away from the S-bend 4 in different directions. The first and second arms 6, 8 are spaced apart in a direction transverse to their length.

25 It is apparent from Figure 2 that when a pair 10 of links 2 are arranged so that the respective S-bends 4 overlap 0. in a manner where the respective first arms 6 extend in opposite directions, the overlapping S-bends form a continuous loop 12 in the shape of a figure-eight. The figure-eight loop 12 consists of two contiguous oval shaped loops 14, 16. The figure-eight loop 12 of the pair 10 can releasably engacle a corresponding figure-eight loop formed in an adjacent paiir of links by virtue of one of the oval shaped loops 14 or 16 engaging with a complementary oval shaped loop 16' or 14' respectively in %hat adjacent pair. This manner of engagement of adjacent pairs to form a prickle chain is 5 described in more detail hereinafter with reference to figure 3.

The link 2 is made by suitably bending a diameter solid bar of carbon steel or mild steel. The overall length of the bar prior to bending is approximately 590mm and the length of the link after bending approximately 420mm. Each of the first and second arms 6, 8 are in the order to 175mm long, with the transverse distance between the first and second arms being in the order of 60mm. The radius of curvature of the curved portions of the S-bend 4 is in the order of 20mm. The height of the gaps in the S-bend 4 are in the order of 22mm.

With reference to Figure 3 it can be seen that a length of prickle chain 20 comprises a plurality of releasably engaging links 2, each link 2 including a central linking portion 4 in the form of an S-bend, the links 2 arranged in adjacent pairs 22, 23, 24 each pair 22, 23, 24 arranged such that the respective S-bends 4 overlap in the o manner so as to form a respective continuous loop 26, 27, 28 o 20 in the shape of a figure-eight. The figure-eight loop 26 formed by the overlapping S-bends 4 of the pair 22 releasably 0 S 0 engages with the continuous loop 28 formed by the overlapping S-bends 4 of the adjacent pair 24 thereby forming the length of the prickle chain 20. The figure-eight loop 26 similarly 25 releasably engages with the figure-eight loop 27 formed in opposite adjacent pair 23, thereby extending the length of the prickle chain .Each link 2 of the prickle chain 20 includes first and second arms 6 and 8 which are connected to and extend away from the S-bend 4 in different directions. The first and second arms 6, 8 of each link 2 are spaced apart in a S•direction transverse to their length. The figure-eight loops 26, 27, 28 are formed by overlapping the links 2 in respective pairs 22, 23, 24 in a manner such that the respective first arms 6 of the links 2 in each pair extend in opposite directions, in identical fashion to that illustrated in Figure 2.

6 The figure-eight loop 26 formed in pair 22 comprises first and second oval-shaped loops 30 and 32.

Similarly, the figure-eight loops 27 and 28 comprises first and second oval-shaped loops 34, 36; and 38,40 respectively.

The first oval-shaped loop 30 of pair 22 engages with the second oval-shaped loop 36 of the adjacent pair of links 24.

The second oval-shaped loop 32 of pair 22 engages with the first loop 38 of opposite adjacent pair 23. Additional pairs of links 2 may be added to the prickle chain 20 in a similar fashion until a desired length of chain is formed.

The pair of links 24 can be made to releasably engage the pair of links 22 in the following manner. The second arm 8 of the right hand side link 2 of pair 24 is passed through the first loop 30 from behind the pair of links 22. Next, the second arm 8 of the left hand side link 2 of pair 24 is passed through the first loop 30 from in front of the pair 22. In this manner, the S-bends 4 of the links 2 in the pair 24 overlap to form the figure-eight loop io* 28 in which the second oval-shaped loop 36 engages with the 0 20 first oval-shaped loop of pair 22. When arranged in this manner, the pair of links 22 are disposed in a plane :o perpendicular to a plane containing the pair of links 24.

The pair of links 23 can be made to releasably engage the pair of links 22 in the following manner. The 25 first arm 6 of the right hand side link 2 of the pair 23 is 'oo. passed through the second loop 32 from in front of the pair 22. Next, the second arm 8 of the left hand side link 2 of the pair 23 is passed through the second loop 32 from behind the pair 22. In this manner, the S-bends 4 of the links 2 in pair 23 overlap to form the figure-eight loop 27 in which the first oval-shaped loop 38 engages with the second oval shaped loop 32 of pair 22. When arranged in this manner, the pair S" of links 23 are disposed in a plane parallel to the plane containing the pair of links 24. In order to extend the length of the prickle chain 20, additional pair of links can be added in a similar fashion.

7 It is apparent from the above description that a prickle chain in accordance with the present invention can be assembled without the need of any tools or separate mechanical fasteners of linking means. Accordingly, the length of the chain may be conveniently varied by either inserting or removing pairs of links 2 by hand. The prickle chain 20 may be attached to any type of draught frame and used in a conventional manner. The arms 6, 8 of the links in the prickle chain act as tines to break clods or remove weeds from the earth. Due to the manner in which the links 2 are engaged within the chain 20, the links 2 are able to twist to a limited degree about an axis parallel to the length of the chain 20. The twisting to the links 2 provides the chain with a degree of resilience and assists in the use of the chain.

,Now that a preferred embodiment of the prickle :chain and link therefor have been described in detail, it will be apparent to those skilled in the mechanical arts that numerous modifications may be made to the chain 20 and link 2 without departing from the basic inventive concepts. For example, in the illustrated embodiment, the links 2 are shown as an integral length of metal bar. However, the arms 6 and a 8, and the S-bend 4 may be made of individual pieces and connected together to form the individual links 2.

Furthermore, although the central linking portions 4 are shown to be in the shape of an S-bend, other shapes may be used, provided that when a pair of links 2 are arranged to overlap the overlapping central linking portions 4 form a *fee continuous loop. All such variations and modifications are to be considered within the scope of the invention, the nature of which is to be determined from the foregoing description.

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Claims

1. A ;ubstantially planar link for a prickle chain, said link comprising: a central linking portion and first and second arms connected to and extending away from said central linking portion in different directions; said arms being spaced apart in a direction transverse to their length, wherein the central linking portion of each link is shaped such that when a pair of said links are arranged so that the central linking portions of each link overlap in a manner where the respective first arms e'i: extend in different directions, the central linking portions form first and second continuous loops, whereby, in use, a first loop formed by overlapping one pair of links can releasably engage a second loop formed by an adjacent pair of *overlapping links,

2. A link according to claim 1 wherein said first and second arms are integral with said central linking portion which is formed intermediate of said first and second 20 arms. e*

3. A link according to claim 1 or 2 wherein said central linking portion is substantially S-shaped.

4. A prickle chain comprising: a plurality of links according to claim 1, said links arranged in pairs, the links in each pair arranged such that the respective first arms of each link extend in opposite directions and the central linking portion of each link overlap to form first and second continuous loops, said pairs arranged so that a first loop of one pair of said links releasably engages a second loop of an adjacent pair of links, thereby forming said prickle chain. 9 A prickle chain according to claim 4, wherein said adjacent pair engage with said one pair by passing the second arm of one of the links of said adjacent pair through the first loop formed in said one pair, in one direction, and passing the second arm of the other link of said adjacent pair through the first loop in an opposite direction.

6. A prickle chain according to claims 4 or wherein an opposite adjacent pair can be made to engage with said one pair by passing the first arm of one of the links of 10 the opposite adjacent pair through the second loop formed in said one pair in one direction, and passing the first arm of the other link of the opposite adjacent pair through the second loop in an opposite direction. 7, A prickle chai., according to claims 4 to 6 wherein said central linking portion is substantially S- shaped.

8. A prickle chain according to claims 4 to 7 wherein said continuous loop formed by the overlapping central link portions in a pair of links is of substantially 1 20 figure-eight-shaped construction. S

9. A link for a prickle chain substantially as herein described with reference to and as illustrated in the accompanying drawings. A prickle chain substantially as herein described with reference to and as illustrated in the accompanying drawings. Dated this 3rd day of August, 1994. NEIL BERNARD NORRISH By His Patent Attorneys: GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia. J;~