Walter Pederson received a US patent dated April 7, 1925, that
covered the concave face on this iron. Pederson theorized that the
convex face would impart backspin to the ball by causing the ball to
roll up the face. Needless to say, few people bought in to his theory
which explains why so few convex face irons remain today.
A good way to demonstrate the convex shape of this face is to place a straightedge ruler across the face and then roll it up from the bottom and back down at the top. A large amount of space between the face and the ruler is visible wherever the ruler is not touching.
The back of this head is stamped "Pat. Pend., Pederson Mfgs., Mount
Vernon, NY, Mashie" along with "Ken Winton", the owner's name. The shaft and
grip are original.
TCA2 V1 p288