Osaka District Court, 1991 (Wa) 585 [Method of Manufacturing Anchors]
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Article information
Article type: Case note
Category: Patents
Topics: AI and intellectual property
First published on this website: 2026-11-01
Display and classification checked: November 2, 2026
Originally published on Ameblo: 2025-02-26 (Japan time). Full English translation.
Osaka District Court, 1991 (Wa) 585 [Method of Manufacturing Anchors]
*The contract was terminated because of defects in prototypes, but repeated improvements led to completion of Product Ha.
⇒ Preparation for a business: established
⇒ Prior-use right: established
“The defendant's method differs in using an eccentric rotary press, but the patented invention … places no limitation on the tool used for caulking … within the same technical concept.”
--------------------------------------------
Osaka District Court judgment of July 11, 1995 (1991 (Wa) No. 585, claim for an injunction against manufacture and sale based on patent rights, etc.)
Prior-use right recognized: yes
Subject: method of manufacturing anchors (patent right)
[Facts]
• April 1977: The defendant was established as a stock company for the purpose of designing, manufacturing and selling various anchors
and related activities.
• Around 1978–1979: As an anchor for foamed concrete, the defendant began manufacturing a type inserted into a drilled hole in foamed concrete,
whose leg portions at the tip spread like an umbrella when a nut is tightened
(trade name “Ever Catch”), and began selling it to Seiwa Shoji Co., Ltd. and others engaged in
selling and brokering industrial fasteners.
• Summer 1983: At the time, among anchors whose leg pieces expand when driven into foamed concrete,
the prevalent type consisted of two or three overlapping leg pieces welded together at their heads. However, their appearance
was not very good, so the defendant's representative considered improvements. Referring to the generally practiced method of pressing metal parts to join them to other
parts, he conceived the idea of making an anchor by pressing the heads of leg pieces inserted into a ring.
To realize this structure,
he asked Kazutaka Yoshida, doing business as Yoshida Ironworks, to bundle three iron leg pieces and make an anchor by
crushing their heads under pressure. Shortly thereafter, Kazutaka Yoshida
bundled three iron leg pieces, interference-fitted a washer (ring) around them, removed the drill from a drill press
(a machine that drills holes in metal and other materials by rotating a drill and pressing down from above),
and replaced it with a head having a recess at its tip. While rotating that head, he pressed the projecting portions of the leg pieces,
plastically deforming them to join the leg pieces to each other and to the ring.
By this method (hereinafter the “prior-use method”), he realized the defendant's representative's idea
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and taught it to him. Based on the prior-use method, the defendant ordered dies for the leg pieces from Sanei Ironworks Ltd.
and had subcontractors, including Yasuo Nii, who operated an ironworks, begin manufacturing anchors
(at this stage, Product Ni, with neither support projections nor bulging portions on the leg pieces).
• Second half of 1983: The defendant presented samples of anchors manufactured using the prior-use method to the above Seiwa Shoji Co., Ltd.
and solicited sales. After confirming that the samples were usable in practice,
Seiwa Shoji marketed them to Densan Kogyo Co., Ltd. (current trade name: JEFCOM Co., Ltd.).
Densan Kogyo confirmed their practical usability and decided to purchase them.
An agreement was reached between Seiwa Shoji and the defendant for Seiwa Shoji to purchase the anchors
from the defendant on a continuing basis.
• Around April 1984: To strengthen its production system, the defendant supplied Yoshio Toyoshima, doing business as Toyoshima Ironworks,
with a head, rings and leg pieces like those described above and asked him to process the anchors.
Yoshio Toyoshima accepted.
• April–September 1984: Yoshio Toyoshima processed a total of 2,215 anchors.
• Around May 1984: To finalize the product, Seiwa Shoji requested final manufacturing drawings from the defendant,
and the defendant submitted drawings.
• May 11, 1984: Yoshihiko Kusumi, the person in charge at Seiwa Shoji, approved the final drawings. Shortly thereafter,
Seiwa Shoji ordered 100,000 anchors in each of the three principal sizes,
300,000 in total, from the defendant, with delivery promised three months later. The defendant, however,
was unable to deliver by the deadline, so approximately one month to forty days after that deadline,
Seiwa Shoji terminated the anchor sales contract.
● Filing date: November 29, 1984
• Around the end of 1985: Because the above anchors lacked both bulging portions and support projections and had problems, the defendant made repeated improvements.
Ultimately, it decided to provide support projections on the leg pieces below the desired ring-fixing position,
and made recesses in the die for manufacturing leg pieces with bulging portions to form those support projections. However,
the recesses were placed incorrectly, so in the anchors manufactured with that die (Product I),
the ring was not fixed at the proper position. Another recess was therefore added at the correct position in the die,
forming support projections on the leg pieces where the ring should be fixed (Product Ha). As a result,
anchor manufacture proceeded smoothly, and the defendant began selling anchors on a full scale through Osaka Tohiuke Seisakusho.
Subsequently, the defendant made a new die
and began manufacturing and selling anchors with support projections at the proper ring-fixing position on the leg pieces
(Product Ro).
[Court's reasoning]
“III. Issue 3 (Whether the defendant has a prior-use right in relation to the patent at issue)
1. According to the evidence (Exhibits Otsu 4, 6, 7-1 through 7-16, 8-1 through 8-5, 9 through 12, 15,
18-1 through 18-3, 19 through 24, and 26; witnesses Yoshihiko Kusumi, Kazutaka Yoshida and Yoshio Toyoshima;
and the defendant's representative) and the entire purport of oral argument, the following facts are found.
(1) The defendant is a stock company established in April 1977 for the purpose of designing, manufacturing and selling various anchors and related activities.
From around 1978–1979, it manufactured anchors for foamed concrete that are inserted into a drilled hole in foamed concrete
and whose leg portions at the tip spread like an umbrella when a nut is tightened (trade name “Ever Catch”),
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and sold them to Seiwa Shoji Co., Ltd. and others engaged in selling and brokering industrial fasteners.
In 1983, among anchors whose leg pieces expand when driven into foamed concrete,
the prevalent type consisted of two or three overlapping leg pieces welded together at their heads. Their appearance was not very good,
so the defendant's representative was considering improvements. In the summer of that year, referring to the generally practiced method
of pressing metal parts to join them to other parts, he conceived the idea of making anchors
by pressing the heads of leg pieces inserted into a ring. To realize this idea, he asked Kazutaka Yoshida, doing business as Yoshida Ironworks,
to bundle three iron leg pieces and make an anchor by crushing their heads under pressure.
(2) Shortly thereafter, Kazutaka Yoshida bundled three iron leg pieces, interference-fitted a washer (ring) around them,
removed the drill from a drill press (a machine that drills holes in metal and other materials by rotating a drill and pressing down from above),
and replaced it with a head having a recess at its tip. While slowly rotating that head, he used it to press the projecting portions of the leg pieces,
plastically deforming those portions to join the leg pieces to each other and to the ring. By this method (hereinafter the “prior-use method”),
he realized the defendant's representative's idea and taught it to him. Based on the prior-use method, the defendant ordered leg-piece dies from Sanei Ironworks Ltd.
and had subcontractors, including Yasuo Nii, who operated an ironworks, begin manufacturing anchors.
(3) In the second half of 1983, the defendant presented samples of anchors manufactured using the prior-use method to the above Seiwa Shoji Co., Ltd.
and solicited sales. After confirming that the samples were usable in practice, Seiwa Shoji
marketed them to Densan Kogyo Co., Ltd. (current trade name: JEFCOM Co., Ltd.). Densan Kogyo likewise
confirmed their practical usability and decided to purchase them. Consequently, an agreement was reached between Seiwa Shoji
and the defendant for Seiwa Shoji to purchase the anchors from the defendant on a continuing basis.
In response, to strengthen its production system, around April 1984 the defendant also asked Yoshio Toyoshima, doing business as Toyoshima Ironworks,
to process the anchors, providing him with a head, rings and leg pieces like those described above. Judging from the processing quantity and fees,
it was an extremely small job, but Yoshio Toyoshima was impressed by the defendant's representative's enthusiasm and accepted. Yoshio Toyoshima
processed a total of 2,215 anchors from April through September of that year (at ¥3.2 each, totaling ¥7,088)
(the delivery slips issued in Toyoshima Ironworks' name to the defendant [Exhibits Otsu 7-1 through 7-16] were in practice filled out by the defendant's representative
so as not to trouble Yoshio Toyoshima. Further, because the defendant lost the receipts for these processing fees,
around April 1991, when the defendant was to undergo a tax audit, Yoshio Toyoshima reissued them at the defendant's representative's request
[Exhibits Z 8-1 through 8-5].).
(4) Seiwa Shoji requested final manufacturing drawings from the defendant to finalize the product.
Around May 1984, the defendant submitted the drawings in Exhibit Otsu 4 (dated April 5 of that year; trade name “Sun Nail”),
and on May 11 Yoshihiko Kusumi, Seiwa Shoji's person in charge, approved them. The drawings show three leg pieces bundled together
to the left (toward the anchor tip) of “C,” apparently the ring, while anchor head E is shown to the right of “C”
(toward the anchor head). E's diameter is larger than the diameter of the three bundled leg pieces,
and the lower left of the drawing states: ‘Pass the head portion “E” through “C” and caulk it.’ (Thus, it can be understood
that three leg pieces are bundled together, a ring fitted around them, and their projecting head portions pressed by caulking and deformed
so that they spread outward.)
Shortly after submission of the final drawings, Seiwa Shoji ordered 100,000 anchors in each of the three principal sizes,
300,000 in total, from the defendant, with delivery promised three months later. However, owing to the circumstances described in (5) below,
the defendant was unable to deliver the anchors by the deadline. Approximately one month to forty days after the deadline,
Seiwa Shoji terminated the anchor sales contract.
(5) Those anchors lacked both bulging portions and support projections immediately below the rings on the leg pieces (Product Ni),
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causing problems such as the ring slipping too far down or stopping at an angle after pressing. Even when skilled technicians
carefully took time to manufacture them, twenty to thirty percent were defective.
The defendant therefore asked Kazutaka Yoshida to improve them. He first added bulging portions to the leg pieces to stop the rings there,
but defects still occurred. The defendant then devised a method of narrowing the heads (projecting portions) of the leg pieces and reducing the ring-hole diameter,
thereby creating a step so that the ring would stop where the leg-piece diameter became larger.
However, because the heads were narrow and the allowance for crushing was small, the ring could not be adequately fixed.
(6) In view of these circumstances, the defendant ultimately decided to provide support projections on the leg pieces below the position
where it wished to fix the ring.
(i) First, to save costs, the defendant made recesses for forming support projections in the die used to manufacture the leg pieces with bulging portions described in (5).
However, because the recesses were placed incorrectly, in the anchors manufactured with that die (Product I),
the support projections were entirely removed from the intended ring-fixing position and did not contact the ring. Consequently,
the ring ended up fixed by the bulging portions of the leg pieces.
(ii) To save costs, the defendant then added another recess at the correct position in the die described in (i),
providing support projections where the ring should be fixed on the leg pieces (the leg pieces thus had support projections
at both the correct and incorrect positions: Product Ha). As a result, anchor manufacture proceeded smoothly,
and around the end of 1985 the defendant began selling anchors on a full scale through Osaka Tohiuke Seisakusho.
(iii) Subsequently, the defendant made a new die and began manufacturing and selling anchors with support projections
at the intended ring-fixing position on the leg pieces (Product Ro).
2. (1) According to the facts found in 1 above, in 1983 the prevalent type of anchor whose leg pieces expand
when driven into foamed concrete consisted of two or three bundled leg pieces welded together at their heads. Because their appearance
was not very good, the representative of the defendant, a stock company established to design, manufacture and sell various anchors and conduct related activities,
was considering improvements. In the summer of that year, referring to the generally practiced method of pressing metal parts to join them to other parts,
he conceived the idea of making anchors by pressing the heads of leg pieces inserted into a ring.
To realize that idea, he asked Kazutaka Yoshida, doing business as Yoshida Ironworks, to bundle three iron leg pieces and crush their heads
under pressure to make anchors. Kazutaka Yoshida bundled three iron leg pieces, interference-fitted a washer
(ring) around them, removed the drill from a drill press and replaced it with a head having a recess at its tip,
and, while slowly rotating that head, used it to press the projecting portions of the leg pieces, plastically deforming them
and joining the leg pieces to each other and to the ring. By this method, namely the prior-use method, he realized the defendant's representative's idea
and taught it to him. Accordingly, the fundamental technical concept of the prior-use method—manufacturing anchors by bundling three iron leg pieces,
interference-fitting a ring around them and crushing their projecting portions under pressure—can be said to have been invented by the defendant's representative
without knowledge of the patented invention. Even if completion of the invention required inclusion of the specific pressing method
of removing the drill from a drill press, replacing it with a head having a recess at its tip, and, while slowly rotating that head,
using it to press the projecting portions of the leg pieces, the defendant's representative can be said to have learned that method
from Kazutaka Yoshida.
It is clear that the prior-use method possesses claim element A of the patented invention, ‘fitting a ring around the ends of two or more leg blanks,’
claim element B, ‘caulking those ends to integrate the leg blanks with each other and with the ring, thereby forming the anchor head’
(which, as explained above, means ‘striking or tightening the ends of two or more leg blanks around which a ring has been fitted, using a tool,
to bring the leg blanks and ring into close contact, join and integrate them, and thereby form the anchor head’), and claim element C,
‘a method of manufacturing anchors characterized by the foregoing,’ and falls within the technical scope of the patented invention.
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(2) Moreover, since the summer of 1983, before November 29, 1984, the filing date of the patented invention,
the defendant had already been having subcontractors manufacture anchors using the prior-use method (at that stage, Product Ni, namely anchors whose leg pieces
had neither support projections nor bulging portions). Although there is insufficient evidence to find that those anchors were actually sold to others,
in the second half of 1983 the defendant showed samples of anchors manufactured using the prior-use method (Product Ni) to Seiwa Yuji Co., Ltd.,
a preexisting business partner engaged in selling and brokering industrial fasteners, and solicited sales.
It reached an agreement to sell the anchors to that company on a continuing basis. Around May 1984,
at the company's request, it submitted final manufacturing drawings for the anchors and obtained approval. Shortly thereafter,
it received an order for 300,000 anchors with delivery promised three months later. Even after termination of that sales contract, it continued improving the prior-use method,
and around the end of 1985, when Product Ha was completed, it began selling anchors on a full scale through Osaka Tohiuke Seisakusho and others.
Accordingly, at the time of filing of the patented invention, the defendant can be said to have been actually preparing in Japan
at least to conduct a business of manufacturing anchors using the prior-use method and selling anchors manufactured
using that method.
The prior-use method uses, as the machine pressing the leg-piece heads, a drill press whose drill has been removed and replaced
with a head having a recess at its tip, whereas the defendant's method differs in using an eccentric rotary press.
However, a prior-use right extends not only to the form of practice that the prior user was actually preparing
at the time of filing of the patented invention, but also to modified forms of practice within a scope that preserves the identity of the invention embodied therein.
The patented invention places no limitation on the tool used for caulking in claim element B, and it is clear that the method using a punch
shown in the specification (publication, column 2, line 13 through column 4, line 3) is one embodiment. Thus, the defendant's method
must be regarded as merely a modification of the form of practice within the same technical concept as the prior-use method.
Further, Methods I through Ha among the defendant's methods differ from the prior-use method in that the leg pieces used as material have support projections or bulging portions.
However, the entry of support projections 3b, 3b, 3b or bulging portions 3d, 3d into the circular hole of ring 14 is merely
an additional configuration and does not prevent a finding that the method falls within the technical scope of the patented invention, as explained in II.3 above.
Accordingly, these likewise must be regarded as merely modifications of the form of practice
within the same technical concept as the prior-use method.
(3) According to (1) and (2) above, the defendant must be held to have a prior-use right in relation to the patent at issue within the scope
of manufacturing anchors using the defendant's method and selling anchors manufactured using that method.”
Translator’s notes (editorial)
The source contains hard line breaks within sentences; the English preserves their node count and order and the complete repeated facts and judgment quotation.
The source variously writes the product labels using visually similar characters (Ni/two, Ro/mouth); romanized as I, Ro, Ha and Ni in context.
The quoted source once gives Exhibit “Z 8” and once names “Seiwa Yuji” instead of Seiwa Shoji; these source anomalies are retained in the English.
Personal and business names are romanized from the supplied characters; readings are not specified in the source.
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November 1, 2026: First published on this website.
November 2, 2026: Added article information, classification, topics, language navigation, related articles where the same case was confirmed, consultation guidance, and SEO. The original text and first-published date were preserved.
