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(11) | EP 3 015 014 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | METHOD FOR PRODUCING A SOCKET FOR LEVER FASTENER DEVICES FOR SPORTS FOOTWEAR |
| (57) A method for producing a socket for lever fastener devices for sports footwear, consisting
of carrying out a series of operations on a flat metal strip L which advances in steps
of length P along a blanking machine, characterised by comprising in sequence the
steps of: a) initial blanking operation to punch two holes (4), said holes (4) being aligned along the advancing axis of the metal strip, said holes (4) being equidistant about the central axis through the step length P, b) second blanking operation to punch a further pair of holes (6), said holes (6) being equidistant about the central axis through the step length P, c, d) third and fourth blanking operations on the sheet metal to follow the outline of the plane development 8 of the socket to be produced, e) advancing through one step, f) deformation with punch and die to cause the blanked portion (8) to assume a shape of U cross-section with the free end having the arms (10) closer together and with the base surface rising to blend into the sheet metal, g) advancing through one step, h) bending to connect the two arms (10) of the end portion together to form a cylindrical portion (12). i) advancing through one step, l) compressing the cylindrical portion (12) to bring it to the correct value for the subsequent threading step, m) advancing through one step, n) threading the inner surface of the cylindrical portion (12), o,p) advancing through one step, q) detaching the finished socket from the metal strip, and r) removing the discarded material. |
[0001] The present invention relates to a method for producing a socket for lever fastener devices for sports footwear.
[0002] Lever fastener devices for sports footwear are known. Said devices substantially comprise a fork, to the prongs of which the arms of a U-shaped lever are pivoted on pins. The arms are also connected by a further pin on which a socket is pivoted, in which the puller of a U-bolt is adjustably engaged.
[0003] These known sockets have however the drawback of a substantial product cost as they are generally produced by lathe operations.
[0005] The objects of the invention are to eliminate these drawbacks and provide a socket of low cost which can be machined on its lateral surface.
[0006] These objects are attained according to the invention by a socket production method as described in claim 1.
[0007] A preferred embodiment of the present invention is further clarified hereinafter by way of non-limiting example with reference to the accompanying drawings, in which:
- Figure 1
- is a perspective view of a socket produced by the method of the invention,
- Figure 2
- is a perspective view showing the successive operations to produce the socket starting from a metal sheet,
- Figure 3
- is a plan view thereof,
- Figure 4
- shows a longitudinal section through the socket with the pin inserted.
[0008] As can be seen from the figures, the method of the invention consists of carrying out a series of operations on a flat metal strip L, preferably of steel, which advances in steps of length P along a blanking machine.
[0009] In particular, the method comprises in sequence the steps of:
a) initial blanking operation to punch a control hole 2 and two holes 4, said holes 4 being aligned along the advancing axis of the metal strip and having a diameter less than that of said hole 2, said holes 4 being equidistant about the central axis through the step length P,
b) second blanking operation to punch a further pair of holes 6, said holes 6 being equidistant about the central axis through the step length P,
c, d) third and fourth blanking operations on the sheet metal to follow the outline of the plan development 8 of the socket to be produced,
e) advancing through one step,
f) deformation with punch and die to cause the blanked portion 8 to assume a shape of U cross-section with the free end having the arms 10 closer together and with the base surface rising to blend into the sheet metal,
g) advancing through one step,
h) bending to connect the two arms 10 of the end portion together to form a cylindrical portion 12,
i) advancing through one step,
l) compressing the cylindrical portion 12 to bring it to the correct value for the subsequent threading step,
m) advancing through one step,
n) threading the inner surface of the cylindrical portion 12,
o,p) advancing through one step,
q) detaching the finished socket from the metal strip, and
r) removing the discarded material.
a) initial blanking operation to punch two holes (4), said holes (4) being aligned along the advancing axis of the metal strip, said holes (4) being equidistant about the central axis through the step length P,
b) second blanking operation to punch a further pair of holes (6), said holes (6) being equidistant about the central axis through the step length P,
c, d) third and fourth blanking operations on the sheet metal to follow the outline of the plane development 8 of the socket to be produced,
e) advancing through one step,
f) deformation with punch and die to cause the blanked portion (8) to assume a shape of U cross-section with the free end having the arms (10) closer together and with the base surface rising to blend into the sheet metal,
g) advancing through one step,
h) bending to connect the two arms (10) of the end portion together to form a cylindrical portion (12).
i) advancing through one step,
l) compressing the cylindrical portion (12) to bring it to the correct value for the subsequent threading step,
m) advancing through one step,
n) threading the inner surface of the cylindrical portion (12), o,p) advancing through one step,
q) detaching the finished socket from the metal strip, and
r) removing the discarded material.