Hans Otto Dohmeier v Eisen-Und Drahtwerk Erlau Aktiengesellschaft

[1988] APO 28

In the Matter of the Patents Act 1952 - and - In the Matter of Patent Application No. 545978 in the Name of HANS OTTO DOHMEIER - and - In the Matter of Opposition thereto under Section 59 by EISEN-UND DRAHTWERK ERLAU AKTIENGESELLSCRAFT.

 

DECISION OF A SUPERVISING EXAKINER OF PATENTS:

Background

Application No. 84114/82 was lodged on 24 May, 1982 by Hans Otto Dohmeier, for a patent for an invention entitled "Laminated Wearing Plate Assembly for Tyre Chain". The application was advertised as accepted on 8 August, 1985 and given the serial No. 545978. A notice of opposition was lodged on 6 December, 1985 by Eisen-Und Drahtwerk Erlau Aktiengesellschaft; the grounds of opposition being those specified in all paragraphs of sub-section 59(1), although only matters of prior publication, novelty and section 40 were pursued by the opponent. The matter came to hearing in Adelaide on 11 July, 1988; Mr. C. Vinall, patent attorney, appeared for ERLAU and Mr. Dohmeier was not represented.

The Specification

The specification indicates that the invention relates to tyre protective or traction chains used for example for earth moving vehicles or vehicles used in lumbering. Known such chains comprise connector links or "connectors" parallel to the tyre surface and wearing links or "wearing plates" perpendicular to the surface. A typical known chain has a tread portion and two side-wall portions for fixing the chain to a tyre, and usually three or four wearing plates are connected to each connector. Annular shaped connectors and rectangular shaped wearing plates are known. Wearing plates are made of various alloy steels, which may be through-hardened or case- hardened, and the plates are normally about 12 to 16mm thick.

There are fourteen claims defining the invention, some are as follows:

"1. A tyre chain having a central tread portion and flanking side-wall portions with each portion comprising a substantially uniform, closed network of wearing plates arranged to be substantially perpendicular to the surface of a tyre in use and connectors in the form of closed loops arranged to be substantially parallel to the surface of the tyre in use with the connectors interconnecting the wearing plates by being threaded through at least one opening in each wearing plate, each wearing plate being connected to two connectors and each connector being connected to at least three wearing plates, wherein each wearing plate of the tread portion comprises an assembly of at least two plate elements, each of which is substantially rectangular and has a suitably hardened surface region in excess of 1.5mm thick so that the wearing plate has an aggregate hardened thickness greater than 6mm.

6. A tyre chain as claimed in any of claims 1 to 5, in which at least some of the plate elements have a formation to space them apart from adjacent plate elements.

10. A tyre chain as claimed in any of claims 1 to 9, in which some of the plate elements of at least some of the wearing plate assemblies are of different heights from other plate elements of the assembly.

14. A wearing plate element for a tyre chain substantially as herein described with reference to or substantially as shown in any of the accompanying drawings."

Claims 2 to 5 are directed to features of the plate elements, viz. shape, thickness and material composition; claims 7 to 9 are directed to embodiments of the formation referred to in claim 6; claims 11 and 12 relate to plate elements with sloping ground engaging edges and claim 13 is directed to a tyre chain as described with reference to the drawings accompanying the specification.

Deficiencies in the prior art and advantages of the invention are discussed in the specification, and are summarised as follows:

(i) The thick plates of the prior art are difficult to form and provide with consistent hardness (page 2 last paragraph).

(ii) Presently marketed chains have wearing plates with various thicknesses; the invention allows plate assemblies to be formed by selecting different numbers of one standard thickness plate (page 7 first paragraph).

(iii) The hardness of the wearing plate assemblies of the intention is high for a considerable portion of the thickness of the assembly and persists throughout the height of the assembly. This advantage is referred to in paragraph I on page 8 of the specification and elaborated as follows:

"For example for (sic) an assembly composed of three mild steel plates each 6mm thick has a total laterally hardened portion of about 9mm above 58Rc compared with 3mm for a conventional wearing plate. In the formed event the hardened portion is 50% of the thickness while it is 19% for a comparable 16mm conventional wearing plate. Of course, the conventional wearing plate could be made of an alloy steel which is hardened primarily by temperature control to obtain a hardened portion of 50% that is above 58Rc: however, in this event there will also be a consequent hardening through the plate though not necessarily to the same extent and such hardness may cause the plate to be brittle and subject to fracture under shock loading."

(iv) Paragraph 2 on page 8 reads:

"While the wearing plate assembly of the invention could be formed of alloy steel plates, an advantage of the invention is that mild steel can also be used, such mild steels being easily available and of slightly lower cost than alloy steels."

(v) The "geometry of the situation", involving annular connectors threaded through holes in rectangular plate elements, allows greater thickness of a laminated plate assembly than that possible with a single conventional wearing plate (page 8 last paragraph).

The Evidence

Evidence-in-support consists of declarations by R.K. Maddern, patent attorney, and B.J. Lyster, of Moybern Trading Pty. Ltd.; Mr. Lyster is involved with the merchandising and servicing of tyre chains. The declarations generally dispute the supposed advantages of the invention and attempt to give an indication of the state of the art at the priority date of the claims, i.e. 22 May, 1981.

Disclosures in some of the documents accompanying the declarations are summarised as follows.

US patent No. 3490511 (MULLER & KONIG), exhibit RKM-5. This patent discloses a chain of annular connector links and rectangular wearing links similar to the present invention; figure 4 of the specification shows how reinforcement of the sidewall chain may be effected by arranging the wearing links in pairs adjacent to each other.

US patent No. 4106542 (H.O. DOHMEIER), exhibit RKM-6. This patent also discloses a chain of annular connector links and rectangular wearing links. Surface hardening and through hardening of the chain links are discussed, with the latter process being emphasised as being more suitable for the subject invention.

US patent No. 3943990 (H.W. RIEGER), exhibit RKM-7. This patent discloses annular connector links and annular and rectangular wearing links. It indicates that surface hardening and through hardening of the links are known, the essence of the invention being the use of different steels - the horizontal links having high breaking strength and the vertical links having high wear resistance.

PEWAG brochure, exhibit BLJ-9. This sales brochure shows a range of PEWAG tyre chains available in 1980; several models show arrangements of pairs of annular rings used as vertical wearing links. Deep hardening and surface hardening of the links is discussed.

Evidence-in-answer consists of declarations by the applicant-inventor Mr. Dohmeier and by J.I.J. Fick, a consulting engineer with experience in steel technology. Mr. Dohmeier distinguishes US patent 3490511 from the claims of his Australian application by emphasising that figure 4 of the former "refers to the side walls only of a tyre chain construction", and he distinguishes US patent 4106542 by pointing out that "it does not disclose the lamination of the plate elements". In referring to the PEWAG chain, Mr. Dohmeier deposes that "loops and plates are not comparable for a number of reasons" such as the following:

(i) The permissable wear depth of loops is much less than that of plates and consequently the PEWAG chain must be turned inside out.

(ii) When canted or twisted, as occurs in use, the loops have a limited contact area with each other which causes rapid wear.

(iii) Plates have a greater height of material exposed to wear.

(iv) Loops are usually welded, which can result in a weaker region at the weld or which limits the available choice of steels.

Mr. Fick, in his declaration, points out that the inventive concept resides not in the materials or heat treatment but in the use of laminated wearing plates. I support this view; some of the evidence-in-support and the evidence-in-answer addresses matters relating to material selection, manufacturing techniques and hardening processes, but whilst providing useful background reading, this evidence has no direct bearing on the matters in hand and I will not discuss this evidence in any detail. Mr. Fick reiterates the advantages of the invention, in particular that the wearing plates can be made of relatively cheaper mild steel.

The evidence-in-reply consists of second declarations by Messrs. Maddern and Lyster and an affidavit by Heinrich Trunk, an employee of ERLAU.

In referring to the tyre chains discussed in the previous evidence, Mr. Trunk deposes that "all or nearly all tyre chains of the type referred to are subject to a case hardening process" (page 3), and that "the chains manufactured by the opponent and by other competitors ... use good quality steel with a hardened layer of comparable thickness to the layer referred to in the patent specification 545978" (page 17). Mr. Trunk also comments on some of the supposed difficulties of the prior art and advantages of the invention. For example, he states that in practice there is no difficulty in forming thick plates and providing them with constant hardness. With regard to the advantage referred to on page 8 paragraph 1 of the specification, he comments:

[Mr. Dohmeierl "indicates that if the "alloy steel" (presumably an appropriate alloy steel as recommended by a steel supplier) is hardened to have 50% above 58Rc, there will be consequential hardening throughout the plate which may cause the plate to be brittle and subject to fracture under shock loading. This is extremely misleading, since if normal workshop procedures are followed such a situation will not arise, and indeed the appropriate alloy steel will be less likely to break under service conditions than a low alloy or mild steel plate."

Mr. Trunk also produced ten documents as exhibits accompanying his affidavit. Many of these documents have uncertain dates of publication in Australia, however one document which was available to the public is:

US patent No. 2822851 (BOTTING), exhibit KDS-4, which discloses a tyre chain essentially comprising conventional chain links but also comprising several "road engaging means" on the tyre tread portion, the road engaging means comprising a pair of plate elements one with a V-shaped notch on its road-engaging edge and the other with a central point on its road-engaging edge. The chain is designed for improved traction and the wear elements are greatly spaced.

Mr. Lyster in his second declaration argues that the opponent's chromium-manganese steel links are tougher and less brittle than the applicant's case-hardened mild steel links (pages 7 and 14), that case-hardening and double annular ring chains are well-known (page 9), and because one embodiment of the applicant's invention refers to mild steel plate elements being only 2mm thick, that such plate elements would be through hardened and therefore too brittle (pages 10 and 13). Mr. Maddern's second declaration relates to publication dates of the exhibits in the Trunk affidavit.

Common General Knowledge

Mr. Vinall made submissions in this matter; referring to Mr. Cyster's evidence, he stated:

"His Declarations show advertising brochures of both ERLAU and other manufacturers, and he states that their subject matter is well known. We would suggest that:

(i) the type of plates shown, such as rectangular with holes at either end;

(ii) the linking patterns; and

(iii) the density of each tyre chain, i.e. the difference between traction and wear type chains;

are common general knowledge. We would suggest that any manufacturer would be familiar with a competitor's chains and would be familiar with the great variety of wear plates or elements that have been shown in the exhibits of the LYSTER Declarations. Not only would there be familiarity with various designs such as plates, elliptical links or castillated [sic] heads, but would be common general knowledge that [where] elliptical links were used, that flat plates may be readily substituted."

Mr. Vinall referred to the parts of Mr. Trunk's affidavit where he also comments that plates and "elliptical" links are "obvious equivalents". Mr. Vinall further suggested that case hardening tyre chain links was also a matter of common general knowledge; this was apparent from the evidence and from the applicant's specification, and he cites the following parts of the specification:

(i) (page 2, line 21-24) "As is to be expected the quality of the chain is mostly determined by the wearing plates which, for this reason, have been made of a variety of alloy steels with through-hardening or case-hardening (carburising) as is appropriate."

(ii) (page 6, line 7-11) "The outer hardness of 58 to 62 Rc to a depth of about 1.5mm is considered by' persons skilled in the art to be optimal for good abrasion resistance."

On the weight of evidence, submissions and disclosures in the applicant's specification, I conclude the following matters to be common general knowledge at the priority date of the claims:

(i) Rectangular plates were one form of wearing links in tyre chains.

(ii) Wearing links of various forms were used on the tread and/or sidewall portions of the chains.

(iii) Mild steel and alloy steels were materials used for wearing links.

(iv) Surface hardening techniques were applied to the chains, about 1.5mm being a typical depth of a hardened surface region of a wearing link.

Prior Publication, novelty

US Patent 3490511

Most of the features of claim I of the applicant's specification are disclosed in this US patent; two features are not disclosed viz:

(i) some of the wearing plates are in the tread portion of the chain, and

(ii) the wearing plate elements have hardened surface regions in excess of 1.5mm thick.

Neither of these two features are directly related to the essential inventive concept of the applicant's invention, namely the use of laminated plate elements as the wearing links in the tyre chain. The first feature is a matter of common general knowledge as discussed above. With regard to the second feature : firstly it is known that the hardened surface regions may be in the order of 1.5mm thick, secondly the specification does not elaborate on why the invention as claimed has hardened surface regions "in excess of" this known thickness, thus I cannot treat this minor variation from what is known as involving any inventive ingenuity. Presumably the phrase "in excess of 1.5mm" in the claim is merely ensuring that there is a minimum thickness of hardened surface regions.

The differences between the disclosure of the US patent and the applicant's claim 1 I consider to be such that the US patent could not be considered as an infringement, and thus the claim is not prior published. See General Tyre & Rubber Co. v. Firestone Tyre & Rubber Co. Ltd. & Ors. [1972] RPC at 485. However in considering the ground of novelty it is permissable to add common general knowledge to extend a disclosure. In Acme Bedsteads v. Newlands Bros. Ltd (1929) 58 CLR 689 the High Court decided that there was no inventive ingenuity involved where differences between what was known and a claimed invention to a hospital bed amounted to a workman in the art simply choosing the most convenient means to adjust the height of the bed; common knowledge in the art was applied and two features, a ratchet and pawl device and a telescopic central post, were chosen. In this present case, which also involves two differentiating features, I cannot see any inventive ingenuity involved in applying the wearing plates to the tread portion of the chain and hardening the surface regions of the plate elements. This lack of inventive ingenuity establishes the plea of want of novelty. See Hume Pipe Co. (Australia) Ltd. v. Monier Industries Ltd (1943) 13 AOJP 578.

I will now consider the other claims of the applicant's specification. The feature of claim 2 is shown in figures 2 and 3 of the US patent. With regard to claims 3 and 4 : firstly the applicant's specification on page 7 indicates that "presently marketed chains have wearing plates with thicknesses of 10, 12, 14 and 16mm", secondly in the US patent cited figure 4 shows the laminated plate elements as about half the thickness of the single plates shown in figure 3, thus I interpolate that the laminated plate elements shown in figure 4 of the US patent would be about 5-8mm thick. This thickness is of the order claimed in the applicant's claims 3 and 4. Claim 5 is directed to "alloy steel or mild steel that is case-hardened"; these features are well known.

Claims 6-9 refer to the plate element spacing formations shown in figure 6 of the applicant's specification. The specification on page 7 indicates that the formations are used to separate the plate elements, when they are constructed of mild steel, to allow carburising of the surfaces of the elements in a gaseous or liquid atmosphere. However, claims 6-9 are not directed specifically to mild steel plate elements, and insofar as they may include elements of other materials the features of claims 6-9 do not offer any advantages over the prior art. I note also that claim 6 only specifies that "some" of the elements have the formations. This implies that some may not; in which case some areas of the plate elements may not be hardened if there are no formations therebetween, thus leading to weak points in the chain, and such a chain would also not offer any advantages over the prior art.

Claims 10-12 are directed to features which I consider to be mere workshop variations of the invention. Page 7 of the specification, refers to these features, as shown in figures 2 and 3, and indicates that the constructions of plate elements with varying heights and sloped edges are to increase traction properties of the chain. Such variations I consider would be readily apparent to a skilled worker in the art who would be familiar with the concept of improving traction with non-continuous surfaces. Some of the evidence accompanying Mr. Cyster's declaration shows-wearing plates with castellated surfaces, which appears to me to be an example of the application of such a concept.

Thus I consider claims 2-12 to be not novel in the light of US patent No. 3490511. Claim 13 also is not novel, there being no feature shown in the drawings which, if not already discussed above with regard to other claims, has any apparent advantage over the prior art. Claim 14 is prior published by the US patent; any plate element as shown in figure l of the applicant's specification is substantially the same as any plate element shown in figure 4 of the US patent.

PEWAG Brochure

Most of the features of claim 1 of the applicant's specification are disclosed in this citation; the differences being firstly that the applicant uses a laminated plate wearing link whereas the PEWAG brochure discloses double-ring wearing links, and secondly the hardened surface regions in the applicant's wearing links are in excess of 1.5mm thick. This second difference as discussed above involves no inventive ingenuity in the light of common general knowledge and is not a novelty-conferring feature. With regard to the first difference, Mr. Vinall submitted that claim 1 is prior published by and not novel in the light of the PEWAG disclosure; he suggested that annular (or elliptical) and rectangular wearing links are "obvious equivalents" and therefore "we fail to see how a skilled addressee who would be familiar with these tyre chains could not recognise the use of rectangular plates as substitutes for the wear elements shown in the PEWAG tyre chain". However I think this argument is rather oversimplified. From the evidence I deduce that single rectangular plates and single annular rings are well known wearing links, but they are n6t exact equivalents because they have different wearing properties due to their shape. Double rings are known, as shown in the PEWAG disclosure, but not as a matter of common general knowledge, and in the light of the applicant's submissions on the wearing problems of double-annular links as discussed above, I conclude that there is an element of inventive ingenuity in the applicant's use of laminated rectangular plates. The laminated plates are the essential feature of the invention, they are not disclosed in the PEWAG brochure and they appear to have some merit and advantage over the prior art. Thus I conclude that the claims are novel in the light of the PEWAG brochure.

US Patent 2822851

The following features of claim 1 of the applicant's specification are not disclosed in this citation:

(i) a network of wearing plates on the sidewall portions of the chain,

(ii) the wearing plate elements are substantially rectangular, and

(iii) the plate elements have hardened surface regions in excess of 1.5mm thick.

Thus, because of these three differences I conclude that this US patent is a weaker citation than US patent No. 3490511, and it is not necessary to compare it to the applicant's claims in any detailed analysis.

Section 40

Claim 14, which is directed to a wearing plate element per se, does not define the invention described which essentially involves the use of multiple plate elements in a composite wearing plate assembly. None of the wearing plate elements shown in the drawings of the applicant's specification embodies this inventive concept. Claim 14 therefore does not comply with the requirements of section 40(l)(b).

Conclusion

I find that the opposition succeeds on the grounds of prior publication, novelty and non-compliance with section 40. I cannot say for certain that there is no patentable subject matter disclosed in the specification and consequently I allow Hans Otto Dohmeier 60 days from the date of this decision to propose amendments with a view to causing the specification to claim that matter.

I award costs against the applicant.

(J.I. WELSH)

Supervising Examiner of Patents

20 SEP 1988

Patent attorneys for the applicant: Collison & Co., Adelaide

Patent attorneys for the opponent : R.K Maddern & Assoc., Adelaide