(19)
(11) EP 4 778 599 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
07.10.2026 Bulletin 2026/41

(43) Date of publication A2:
22.07.2026 Bulletin 2026/30

(21) Application number: 26173786.0

(22) Date of filing: 02.03.2023
(51) International Patent Classification (IPC): 
A63B 53/04(2015.01)
 A63B 60/02(2015.01)
(52) Cooperative Patent Classification (CPC):
A63B 53/0408; A63B 53/0458; A63B 53/047; A63B 60/02
(84) Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR

(30) Priority: 11.03.2022 US 202217654555
11.03.2022 US 202263269232 P
28.04.2022 US 202263363780 P
18.05.2022 US 202263364949 P
29.08.2022 US 202263373831 P
07.10.2022 US 202263378811 P

(60) Divisional application:
26184864.2 / 4803163

(62) Application number of the earlier application in accordance with Art. 76 EPC:
23767574.9 / 4489875

(71) Applicant: Karsten Manufacturing Corporation
Phoenix, AZ 85029 (US)

(72) Inventors:
  • HUANG, Yujen
    Phoenix, Arizona, 85029 (US)
  • HENRIKSON, Erik, M.
    Phoenix, Arizona, 85029 (US)
  • SCHIER, Matthew, T.
    Phoenix, Arizona, 85029 (US)
  • SIMONE, Matthew, W.
    Phoenix, Arizona, 85029 (US)

(74) Representative: Tombling, Adrian George 
Withers & Rogers LLP 2 London Bridge
London SE1 9RA
London SE1 9RA (GB)

   


(54) MULTI-STAGE FORGING PROCESS


(57) An iron-type golf club head with a cavity formed via a multi-stage forging process. The forged iron-type golf club head is formed from a single billet of material. An intermediate step of the multi-stage forging process creates a cavity in the iron-type golf club head which can receive an insert. The resultant iron-type golf club head has a substantially lower center of gravity and higher moment of inertia when compared to a traditionally forged iron-type golf club head lacking a cavity. Additionally, the resultant iron-type golf club head has a more solid feel than a traditionally cast iron-type golf club head as a result of the tighter grain structure the forging process yields.







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Search report