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Tpr Co., Ltd.

USPTO Granted Patents = 62

% Expired Patents = 1.6

EPO Patents = 45

Forward Citations = 88

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94 inventors (with patents filed for the assignee):

Koichi Hatakeyama (7 out of 7 patents)

Akira Hikone (7 out of 7 patents)

Akira Sato (7 out of 13 patents)

4. Kiyoyuki Kawai (6 out of 38 patents)

5. Atsushi Nakazawa (5 out of 8 patents)

6. Noriaki Ayuzawa (5 out of 5 patents)

7. Masahide Hama (5 out of 5 patents)

8. Yutaka Kitazume (4 out of 4 patents)

9. Seiji Tamaki (4 out of 5 patents)

10. Tomoyuki Sato (4 out of 9 patents)

11. Shohtaroh Hara (4 out of 4 patents)

12. Hidemi Kato (3 out of 11 patents)

13. Takatsugu Iwashita (3 out of 3 patents)

14. Takashi Sato (3 out of 12 patents)

15. Takashi Oizumi (3 out of 3 patents)

Core Competencies:

Piston Ring

Casting System

Thermoelectric Conversion

Cylinder Liner

Sliding Member

Sintered Alloy

Oil Control Ring

Multi-Walled Carbon Nanotube

Valve Seat

Compression Ring

Drip Prevention Device

Centrifugal Casting Mold

62 patents: Sort by Forward Citations

1. 12521788 - Drip prevention device for pressurized pouring furnace (2026-01-13),

2. 12485476 - Casting system (2025-12-02),

3. 12397343 - Mold cooling device, cast manufacturing system, and cast manufacturing method (2025-08-26),

4. 12392301 - Piston unit, top land member, and combination of piston unit parts (2025-08-19),

5. 12305590 - Spiny liner and manufacturing method of same, and method of determining bonding strength (2025-05-20),

6. 12292118 - Piston ring (2025-05-06),

7. 12281380 - CRN coating film and sliding member (2025-04-21),

8. 12196325 - Compression ring (2025-01-14),

9. 12173799 - Oil control ring (2024-12-24),

10. 12121958 - Centrifugal casting mold and centrifugal casting mold assembly device (2024-10-22),

11. 12117084 - Combination of piston rings, and combination structure of piston and piston rings (2024-10-15),

12. 12116951 - Cylinder liner and cylinder bore (2024-10-15),

13. 12092222 - Piston ring combination, and internal combustion engine (2024-09-17),

14. 12066111 - Piston ring (2024-08-20),

15. 12058937 - Thermoelectric conversion module and structure for thermoelectric conversion element (2024-08-06),

Tpr Co., Ltd., headquartered in Tokyo, Japan, specializes in advanced piston ring technology, focusing on the development and manufacturing of high-performance components for internal combustion engines. The company is recognized for its expertise in casting systems, thermoelectric conversion, and the production of sliding members and cylinder liners. Tpr also innovates in oil control rings and sintered alloys, leveraging multi-walled carbon nanotube technology to enhance the durability and efficiency of automotive applications.

Profile summary based on public USPTO records.

Company Badge

USPTO Data Jan 1 1976 - Sep 29 2026

62 Patents

#710 in Tokyo

#1,499 in Japan

#11,755 in the World

Tpr Co., Ltd.

Forward Citations = 88

94 inventors:

Koichi Hatakeyama (7 out of 7 patents)

Akira Hikone (7 out of 7 patents)

Akira Sato (7 out of 13 patents)

4. Kiyoyuki Kawai (6 out of 38 patents)

5. Atsushi Nakazawa (5 out of 8 patents)

Please report any incorrect information to [email protected]

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