Bicycle drop-out and method of attachment
AssigneeSandvik Special Metals Corporation
InventorsDennis J. Stauch, William E. Shaffer
Life of this patent
Estimating the term…
Abstract
A dropout for a bicycle receiving tube includes an integral consumable ring which is melted upon the application of heat thereto to form a weld joint between the tube and the dropout. A one-piece dropout for a front axle includes a cylindrical mounting portion, a slotted front portion, and a tapered transition portion. The dropout can be cast or machined from a single piece of barstock such that the slotted front portion is offset radially inwardly relative to a largest outer diameter of the dropout. A three-piece dropout for receiving a rear axle includes two transition elements and a slotted plate welded to the transition elements.
Claims26
A one-piece metal dropout adapted to be attached to a hollow metal receiving tube of a bicycle for retaining a front axle, comprising:
- a rear section including a cylindrical mounting portion sized to be inserted into the receiving tube, said cylindrical mounting portion being hollow to form a rearwardly open recess, a radially outwardly projecting shoulder disposed at a front end of said mounting portion for limiting the depth of insertion of said dropout into the receiving tube,
- a front section including an axle-receiving portion having an axle-receiving slot, a thickness of said axle-receiving portion being less than an outer diameter of said mounting portion, and
- a transition portion disposed between said rear section and said axle-receiving portion and tapering toward said axle-receiving portion, a hole extending through said transition portion and opening into said recess in said mounting portion, said hole being of smaller cross section than said recess,
- said axle-receiving portion being offset radially outwardly relative to a longitudinal axis of said mounting portion and offset radially inwardly relative to the largest outer diameter of said dropout.
A one-piece metal dropout adapted to be attached to a hollow metal receiving tube of a bicycle for retaining a front axle, comprising:
- a rear section including a cylindrical mounting portion sized to be inserted into the receiving tube, and an intermediate portion disposed forwardly of said mounting portion,
- a front section including an axle receiving portion having an axle-receiving slot,
- a transition portion disposed between said intermediate portion and said axle receiving portion and being tapered toward said axle-receiving portion, and
- a consumable ring disposed between said mounting portion and said intermediate portion, said consumable ring having a larger diameter than said mounting portion and said intermediate portion and being consumable during a welding operation to form a weld joint between said intermediate portion and a receiving tube.
A metal dropout adapted to be attached to seat stay and chain stay tubes of a bicycle for retaining a rear axle, comprising:
- two transition elements, each including:
- a rear section formed as a cylindrical mounting portion sized to be inserted into
- a respective one of said tubes, and
- a front section having a curved wall shaped as a segment of a cone whose longitudinal axis corresponds to a longitudinal axis of said rear section, and a front-to-rear extending contact surface extending between opposing edges of said curved wall, and
- a slotted plate attached to said transition elements and engaging said contact surfaces thereof.
A one-piece transition element adapted for attachment to a tube of a bicycle and to a slotted plate which receives a rear axle, comprising:
- a rear section formed as a cylindrical mounting portion sized to be inserted within said tube, and
- a front section having a curved wall shaped as a segment of a cone whose longitudinal axis corresponds to that of said mounting portion, and a front-to-rear extending, substantially flat contact surface extending between opposing edges of said curved wall.
A method of making a one-piece dropout for receiving a front axle of a bicycle, comprising the steps of:
- A. providing a cylindrical metal barstock having a cylindrical outer periphery,
- B. machining a midsection of said cylindrical metal barstock to taper said midsection toward a front section of said barstock,
- C. machining a rear section of said barstock to form a rearwardly facing radial shoulder therein,
- C. machining said front section into the shape of a flat plate having an axle-retaining slot, whereby said flat plate is spaced radially outwardly from a longitudinal axis of said barstock and radially inwardly from said cylindrical outer periphery and
- E. machining one side of said tapered midsection to form a surface extending from a rear section of said barstock to said plate, whereby a final orientation of said plate with respect to said longitudinal axis is established by steps D and E.
A front steering fork for a bicycle comprising:
- a pair of receiving tubes having hollow lower ends, and
- one-piece metal dropouts welded to respective ones of said lower ends, each of said dropouts having a slot for receiving a front axle, each dropout further including:
- a rear section including a cylindrical mounting portion seated within the respective receiving tube, said mounting portion being hollow to form a rearwardly open recess, a radially outwardly projecting shoulder disposed at a front end of said mounting portion limiting the depth of insertion of said dropout in the respective receiving tube, said shoulder being welded to said respective receiving tube,
- a front section including an axle-receiving portion having an axle-receiving slot, a thickness of said axle-receiving portion being less than an outer diameter of said mounting portion, and
- a transition portion disposed between said rear section and said axle-receiving portion and tapering toward said axle-receiving portion, a hole extending through said transition portion and opening into said recess in said mounting portion, said hole being of smaller cross-section than said recess,
- said axle-receiving portion being offset radially outwardly relative to a longitudinal axis of said mounting portion and offset radially inwardly relative to the largest outer diameter of said dropout.
A one-piece metal dropout adapted to be attached to a hollow metal receiving tube of a bicycle for retaining a front axle, comprising:
- a rear section including a cylindrical mounting portion sized to be inserted into the receiving tube,
- a front section including an axle-receiving portion having an axle-receiving slot, a thickness of said axle-receiving portion being less than an outer diameter of said mounting portion, and
- a transition portion disposed between said rear section and said axle-receiving portion and tapering toward said axle-receiving portion,
- said rear section including a cylindrical intermediate portion disposed between said mounting portion and said transition portion,
- said axle-receiving portion being offset radially outwardly relative to a longitudinal axis of said mounting portion and offset radially inwardly relative to the largest outer diameter of said dropout,
- a radially outwardly projecting consumable ring disposed adjacent a front end of said mounting portion, said consumable ring having a larger diameter than said mounting portion and said intermediate portion and being consumable during a welding operation to form a weld joint between the dropout and the receiving tube.
A method of making a one-piece dropout for receiving a front axle of a bicycle, comprising the steps of:
- providing a cylindrical metal barstock having a cylindrical outer periphery,
- machining a midsection of said cylindrical metal barstock to taper said midsection toward a front section of said barstock,
- machining said front section into the shape of a flat plate having an axle-retaining slot, whereby said flat plate is spaced radially outwardly from a longitudinal axis of said barstock and radially inwardly from said cylindrical outer periphery,
- machining one side of said tapered midsection to form a surface extending from a rear section of said barstock to said plate, and
- machining a rear section of said barstock to form a radially outwardly projecting consumable ring therein.
Dependencies are inferred from the claim text.